Fish Disappearing/Mantis Shrimp? 11/17/09
Hi,
<Hello Arturo>
half a year back I contacted you to find out methods to capture mantis shrimp. Well ever since I bought the live rock for my 175gal, small fish had been disappearing. I´ve lost about 10+ small fish in a period of two years.
Among the missing small fish, the only survivors are two ocellaris clownfish, who have their own RBTA, its been suggested that had kept them safe from threats.
<Certainly helps.>
My other fish left are big fish: 1 Sailfin, 1 hippo blue tang, and one middle size Copperband Butterfly.
I also captured 3 mantis, and according to me, there was one more left who was the tougher.
Well, every night there were clicking noises, I never really saw the bastard,
<Mmm, I'd like to rename to Lysiosquilla bastardi.>
I only followed the noises and started moving rock to the sump.
<OK>
Well one day the clicking noises in the main tank stopped, and they started in the sump. So I dried all of the live rock in the sump for like a week, and once it was completely dried, then I placed it back in the tank.
Clicking noises completely stopped, and after 2 weeks I bought a Bicolor Blenny. The Bicolor Blenny was placed in the display tank and was never to be seen again. What the?, it can´t be, well it was my first blenny.
So I bought an expensive Mystery Wrasse.
<Yikes, you chanced a 200 dollar fish.>
It lived happily in my tank for 3 months and they hide in the rockwork a lot, and nothing would happen to it, very healthy, eating a lot and now its been gone for a week... No signs of splashing, no corpse on the floor, no corpse on filter sock, sump, etc. It completely disappeared...
<"No corpse on the floor"...Do you have a cat by chance?>
When I was sure I had mantis, fish also just disappeared, but now its been like 5 months since I got rid of the clicking noises.
So it's really weird to have a perfectly healthy fish just disappear like that, but now that I remember the blenny incident, then it reminds me a lot of what used to happen when I knew there was mantis, except that this time there´s absolutely no clicking noises, not even at night, I check my tank at night all the time, feed my corals, etc. And no noises, if a critter was to make a clicking sound, I would have heard it by now.
So why is small fish starting to disappear again?.
<My first thought would be that you still have a mantis of the spearing type rather than a smasher. My other thought would be a large Serpent Star, but I'm sure you would have mentioned that. Mmmm, Bob may input his thoughts here. James (Salty Dog)>

Re Fish Disappearing/Mantis Shrimp? 11/17/09
More info on the incident: The mantis I took out were all very small, less than 2" not very colorful, 2 reddish and 1 yellow, and they were all spearers, its been suggested mantis this small can´t kill but the smallest of fish.
<I tend to agree here, prey is generally proportional to the mantis size.>
I wanted a Royal Gramma, so I bought one, and introduced it, and it hid and it was gone forever...then bought another one.....gone forever.....and another one.......gone forever, they were disappearing to quick and they´re among the fish that hide on the rockwork the most.
<Geez, you've got a pretty expensive food bill.>
Although I once bought a small Lemon Peel Tang, and after 3 months of living happily, one mourning I found him full of cuts, something had attacked it, I don´t know what but I figured it was the mantis, it got better and after one month it just disappeared.
<Yikes. I'd be thinking of doing a complete teardown provided you have a Rubbermaid tub or another tank appropriately sized for the fish only.>
Then I bought a couple of banded shrimps, and one day in front of my own eyes a mantis came out of the rock and attacked and killed the male banded shrimp and brought it back to its cave, that´s when I started taking rocks out and lured the mantis with the shrimp´s corpse, until I found its rock and took it out. So it was clear to me that these little mantis were brave, and they were all spearers, and they did clicking noises.
Can there be mantis left that just won´t do clicking noises?. Also when I removed all the rockwork, I put it in freshwater, and nothing came out but small crabs, then I put it in soda water and nothing came out!, and then I just put it to dry, and didn´t see anything else hiding, the only rocks left in the tank before that were really small and without crevices, so I don´t know how a star could actually hid in them.
Yesterday I checked the nano tank in which I also used rock from the main tank, and at night I saw what appears to be a fire worm, and I said to my self "hmm so there are still something left alive" that nano has no fish though.
Crabs have been suggested too, I used to have gorilla crabs, but I captured most of them with a trap and also when removing the liverock. From what I´ve seen crabs always show up at night, and they also do certain clicking noises, and now it seems there´s nothing left.
I´ve also seen aggressive stars, and they´re also quite visible, at least you see tentacles here and there sticking out of the rock!. So I don´t know this is just weird.
<Depending on the size of the Serpent Stars, these could very well be the culprit(s). I'll ask Bob for his thoughts here. James (Salty Dog)><<I concur w/ your speculations, statements. RMF>>

Is the mantis shrimp a fish killer?   11/4/09 Hi there, my husband and I are longtime utilizers of the website, and this is the first time we’ll be asking a question. <Feel free!> I’ve searched and searched, and can’t seem to be sure of the answer. My husband and I recently lost two fish, a dragon goby (about 4-5 inches long), and our very favorite fish, (due to its uncanny friendliness and curiosity) our Midas blenny about 5 inches. <I assume by "Dragon Goby" you mean Amblygobius phalaena rather than Gobioides broussonnetii.> A couple days ago, my husband thinks that he saw a mantis shrimp (smasher kind) and for a month or so we’ve been hearing the tell tale clicking sounds. <Funnily enough, these "clicks" are more often Pistol Shrimps (Alpheidae) or Damselfish such as Clownfish, which grate their pharyngeal teeth when threatening one another.> I haven’t really noticed any of the clean-up crew going missing, but we have quite a few Nassarius and other snails, and I suppose they could be missing without being noticed or were presumed to be (Nassarius) burrowed under the substrate as they are most of the time (we always see some ate feeding time.) <Under aquarium conditions, Mantis shrimps are as likely to take easy food (such as wet-frozen seafood) as food that is hard and time consuming to eat, such as live snails. When I kept my specimens at university, they'd eat snails almost as a last resort once they got used to the fact I was feeding them!> Anyway, all of the other fish seem to be healthy happy and fine, and the two that died were the two that tended to hang out on the side of the tank where my husband says he saw the mantis. <I see...> The thing that confuses me, is that when the fish died, our emerald and hermit crabs seem to have swarmed the area to help “clean up” the dead fish, and didn’t seem to be hurt or bothered by whatever lives under the rock (there is a small burrow where my husband saw the creature.) <As always when fish die prematurely, it's time to review conditions.> Could it be a mantis shrimp that killed our fish? <If it's there, then yes. The differences between "smashers" and "spearers" are more anatomical than ecological. Smashers will quite happily catch and eat fish given the chance, and in an aquarium, such chances come often.> Would it have killed them and allowed the other crew to hang out and eat what was left? <"Allowed" is perhaps too strong a word. Predatory animals take what they can, when they want it... animals that they haven't yet killed aren't necessarily spared, merely not killed and eaten just yet.> Would it be a pistol shrimp and not a mantis that would do this, or something else entirely? <Pistol Shrimps are generally not predatory, more annoying, if you don't like the noises they make. Indeed, some species form symbioses with Gobies. I've kept coldwater Pistol Shrimps together with a whole variety of other marine life and not seen any particular problems.> Were very upset to have lost our favorite pet and would like to find the culprit. Thank you for your help with the situation, we really appreciate your expertise! <Hope this helps.> P.S. we had a small trap baited with mysis shrimp in place for a couple days, but didn’t catch anything but a Nassarius snail and later our six-line wrasse. <Mantis shrimps are very smart and very difficult to remove. Having said this, they are fantastic animals, more interesting than most fish to be honest, and if you can get the Mantis out, then popping it in its own aquarium is well worth doing. There are of course animals that eat them, including Octopuses and Triggerfish, but in terms of biological control these will do more harm to your reef than the Mantis ever will! Do look over Bob's summary of the fascinating animals we call the Stomatopoda. http://www.wetwebmedia.com/marine/inverts/arthropoda/stomatopods/mantisshrimp.htm Cheers, Neale.> Re: Is the mantis shrimp a fish killer? (RMF, what's a Jack Dempsey Damsel?)<<Got me>> Thanks so much for your quick reply! My husband saw the mantis again yesterday and confirmed that it was indeed the smasher type. <I see.> Could the clicks be from a Jack Dempsey damsel? we don't have any other damselfish. <I have no idea what a "Jack Dempsey Damsel" -- and nor does Google!> (The clicks are about as loud as when you snap your fingers, and sound much the same.) <Damselfish clicks tend to sound more like grating. They're not usually loud, and the sort of thing you notice when it's quiet, and find yourself having to listen out for. Mantis Shrimp smashing things sound like taps, while Pistol clicks are very much louder, disturbingly like glass cracking.> I have actually done quite a bit of research on the mantis and I agree that it is a fascinating animal! (you might enjoy the video from Sheila Patek at: http://www.ted.com/talks/lang/eng/sheila_patek_clocks_the_fastest_animals.html It is very interesting) <Indeed, very interesting animals. Briefly worked on a physiology project while an undergraduate, and maintained a collection of two different species for about six months. Nifty things, and seem to learn very quickly.> I am concerned for my other fish, since we have already lost two, I believe though, that perhaps having the trap with the food in it outside the mantis burrow is causing the fish to invade it's territory. <Possibly, but the Mantis will explore at night as well, and potentially take anything sleeping it comes across. While Mantis shrimps don't have huge territories in the wild, under aquarium conditions it's likely all but the biggest tanks would count as a single "home range" for a foraging Mantis.> If I remove the trap, I believe that the fish would stay away from that spot. What do you think? <Don't think this will neutralise the danger at all.> Should I try to feed the mantis shrimp? <You could, but again, this is likely postponing the inevitable. If nothing else, a bigger Mantis shrimp poses more of a threat than a smaller one, and if it's well fed, it's going to grow... You really do want to get this chap out of the reef tank.> if so, what would he like to eat? <Oh, they eat most anything. Mine would eat small crabs, small hermit crabs, prawns, and even juvenile tilapia (I was less enlightened then than I am now about the use of live fish for food). In captivity they are easily weaned onto wet-frozen seafood (squid, prawn, etc.) and things like frozen smelt and silversides (sold in fish shops as "lancefish" usually). They can be hand fed after a fashion, using long forceps or a satay stick. For very, very obvious reasons, you don't hand feed them directly!> Thank you for all of your help. It is really wonderful to have such expert info available! <Glad to have helped. Cheers, Neale.> Re: Is the mantis shrimp a fish killer? (RMF, what's a Jack Dempsey Damsel?) 11/5/09 SORRY I was mixing up fish names! I have a Sergeant Major damselfish, <Abudefduf saxatilis, a nice, if boisterous, fish.> but I have now seen (and photographed) our culprit, and I saw him "click" so I know it's him. <Indeed.> He's moved his burrow (I think because he didn't appreciate our trap) I've attached the pics. Do you have any suggestions on how I can catch him? <Very difficult. Do read here: http://www.wetwebmedia.com/marine/inverts/arthropoda/stomatopods/mantisfaqs.htm Typically a combination of traps and manual removal of live rock ends up being used.> (my husband wants to put him in our nano tank- now empty accept for some snails and Zoanthids) my fish are very curious and a little too friendly and have been trying to investigate him a lot today. :( <Very small Mantis shrimps aren't much of a threat to very much bigger fish, and can often be ignored. But if your fish are too similar in size, then curiosity on their part may have fatal consequences. Cheers, Neale.>

Re: Powder blue to aggressive for a 150gal with 2 tangs? Stomatopod predation   8/18/09
Thanks for your reply, you´re probably right. The problem with the last mantis shrimp is that I thought it was going to be easy to capture like the last 3, but using the clicking sounds as guide, I never really found the rock, I dipped them in freshwater but the thing never came out, etc.
<Perhaps not there... maybe more stubborn or stuck...>
The worst thing is that it seems Montiporas do not tolerate well to be exposed to air, in about 15 minutes of air exposure they got severely damaged, I lost a small tyree blue polyp cap frag, and the other Montis will thrive but are severely damaged. I just found that out, since I´ve never had problems with Acroporas and air exposure.
<This genus is much more sturdy, often exposed to air in the wild>
What kind of small fish will not hide in the rockwork to be a victim of the mantis shrimp?,
<None>
My clowns have no problem, I don´t know if its because they don´t hide in the rockwork or because they are protected by their red bubble tip anemone.
<This latter. Bob Fenner>

good mantis predator?  8/18/09
Hi, I´m trying to get rid of a difficult mantis. I captured 3 but the last one I haven´t been able to capture it in 2 occasions removing rockwork. Getting rocks out with corals caused severe stress to some Montis, I lost one, and the mantis was never to be found not even in freshwater dips.
DIY and commercial traps have never worked. This last mantis managed to take out 1 cb butterfly fish, 1 small flasher wrasse, and 1 3.5" wrasse. All fish that hide in the rockwork. The only survivors are :
1 x 6" sailfin tang
1x 3" hippo tang
2x ocellaris
The sailfin is way to big for this mantis, the hippo seems big enough to discourage the mantis, although it sleeps in the rockwork. And the ocellaris are never attacked probably because the mantis is afraid of their bubble tip anemone or because they never hide in the rockwork.
It seems this mantis should be at most 2" like his previously captured relatives, which I took in a lapse of 2 years and never really found them bigger than 2". I´ve seen bigger mantis and they seem more active, show themselves, etc. So I believe this one is 2" yet very smart, unseen, and deadly.
My only conclusion now is that I must find a good predator, and I mean good. So I need you to recommend me a good one.
I´ve thought about a bird wrasse, how big should it be?,
<A Coris species would be better, a trigger even better still>
are my corals safe?,
<Less so than with your present fishes; but likely "safe enough">
I can give my clam to a friend. I have a commercial fish trap, what commercial food can a bird wrasse accept?,
<Most all, but some meaty food should be included... Spectrum et al. pelleted foods might work as a staple>
how big should it be?.
<About twice the length of the Stomatopod>
If they don´t attack corals then it should be ok. I have acans, Favias, chalices and SPS.
What about Australian Dottybacks?
<Nope>
And finally I thought on an army of pistol shrimp.
<Likely to be consumed themselves>
Don´t know which option is better. Any more suggestions?. Thanks.
<Trapping is the best. Bob Fenner>

A mate for my mantis? - 06/05/09
Hello WWM Crew,
<Rona>
I was wondering if I could get some advice on what I should do with my current mantis situation.
<Sure>
I purchased a peacock mantis I had been wanting a few weeks ago from a store which had her for quite awhile (couple weeks). When I introduced her to her tank she took to it well. She was definitely not a shy creature and immediately treated herself to a big snack out of the snails and hermits that inhabited the tank. It wasn't until a few days later when I noticed that she was starting to block her cave and went into hiding. I figured that she was probably molting and would come out soon. Well, today i got a peek at her and noticed she was carrying a pink sack of eggs!
<Neat!>
After doing some research, i found that these creatures mate for life I remembered that there were 4 mantis shrimps at the store when i originally bought her and wondered if one of those could possibly be her mate.
<Mmmm, maybe>
I contacted the store and the person informed me that she did come in with another smaller mantis (which they still have). My question now is, should I purchase the other mantis and try to introduce them?
<A semi-dangerous proposition... Not really social animals>
If i do decide to introduce them together, do you have any suggestions on how to best handle the situation?
<A divider of substance... removed ONLY with you present in time>
Would i even be able to introduce another mantis without them killing each other?
<Not good odds>
By the way, my mantis currently lives in a 30 gallon tank that has been running for a little over a year.
<Not enough space>
Thanks in advance.
<Welcome. Bob Fenner>

Mantis shrimp/Fireworm compatibility? – 02/12/09
Hello! We trapped a fairly large (about 6" long almost 1/2" dia.) fireworm this evening and removed it from our 240 gal. FOWLR tank. 2 of our fish appeared to have been stung by it recently - bristles on their bodies and a day of decreased appetite/activity and both recovered w/ no lasting effect.
<Ouch!>
We'd rather not have the worm loose in there, but would also rather not kill it (we're wusses like that).
We do have a 5" mantis shrimp set up in his own tank and thought maybe the worm could live there.
<Mmm, not likely>
So...would the mantis eat the worm, or would the worm sting the mantis, or is it a match made in heaven???
Thanks for your help!
Laura
<Chances are the Mantis will consume the worm. Bob Fenner>

Can Mantis Shrimp reproduce Asexually? 2/7/09
Hi WWM Crew,
This is kind of a long saga that has been going on for almost 3 years, but have you ever heard any reports of Mantis Shrimp reproducing asexually?
Background...
When I set up my tank originally, I ordered 60 lbs of LR from the Caribbean. This rock came packed in bags with ocean water, so there was lots of still living creatures in the rock. I immediately heard the "snapping" noise right from the start. My clean up crew was pretty much wiped out. But the snapping was typical, after research, of what you would hear if you had a Mantis Shrimp. After about 6 months, I had added fish and new clean up crew and wasn't getting the deaths I was before, so I left him alone. Then I found him one morning just sitting against the front glass. This was very unusual cause he was always hiding in some hole somewhere, very rarely saw him. So I decided to net him and remove him.
About 1 month later, I hear "snapping" again. I then said to myself.. wow I got pretty unlucky to get 2 of those things. This one continued to live harmoniously for the most part with everyone in the tank for about 6-8 months. (A tang, 2 clowns, 2 damsels, and a green mandarin). I would notice my hermit population slowly reducing or a missing snail here and there, but nothing big. Then one day I found that one just sitting against the front glass.. in the same spot. I decided to remove him too while I had a chance. Fast forward another month or so. I hear snapping... again.
This process has repeated 4 times... I am apparently on my fifth Mantis Shrimp after 3 years. I have not added any rock or anything others could have been hiding in, so I either started with 5 and am the unluckiest person ever or something else is going on. It never seemed/sounded like I had more than one at a time. Although I could have started with 2 that spawned? But I wouldn't think the tiny offspring would survive. I had lots of crabs and other opportunistic eaters at the time. Also, I heard their lifespan is only a couple years, so I wonder if it's even possible I started with 5 of them 3 years ago and still have 1 left alive. The strangest thing to me is the repeated pattern of one just deciding to show itself just laying against the glass one day when I otherwise never see them. I remove them. Then snapping starts again within 3-5 weeks.
Any ideas? am I just super unlucky with the rock I bought?
Thanks,
Cory
<Hi Cory, the short answer is no, Mantis Shrimps do not reproduce asexually. They have a complex life cycle that involves a planktonic stage spanning many weeks, if not months, so breeding in aquaria isn't really possible. Like a lot of the larger crustaceans, the eggs are carried about by the female under her legs, but when the eggs hatch, the fry drift away.
So if you discover new Mantis Shrimps in an aquarium, it is more than likely they were always there, but have simply grown big enough to become noticeable. As for lifespan, it varies from species to species. Anything between 3-5 years is typical for most of them, but can be substantially more: Lysiosquillina maculata specimens in labs have been recorded living
for 20 years. Now, one other thing: are you sure you're not confusing Snapping Shrimps (a.k.a Pistol Shrimps, e.g., Alpheus spp.) with Mantis Shrimps?
http://www.wetwebmedia.com/pistolshrimps.htm
Snapping Shrimps snap, and are also predatory. They can be surprisingly densely packed in some habitats, and I've handled batches of California kelp holdfasts that have yielded literally dozens and dozens per bucketful.
They are hardy and do astonishingly well in captivity, and it would entirely possible you started off with lots of tiny juveniles that have only now become big enough to observe clearly. Snapping Shrimps are unusual in having very abbreviated larval stages, essentially compressing the whole thing into four days or so. It would be possible, though unlikely, I suppose, for Snapping Shrimps to breed in captivity. Cheers, Neale.>

Mantis Shrimp and Crabs in New Live Rock question 05/10/2008
Hi team,
<<Hello, Andrew this evening>>
I've been looking to your website for much information. Lot's of good stuff - Thanks!
<<Great>>
I've read that some people have luck ridding their live rock of mantis shrimp by dipping the individual rocks in club soda for a couple minutes. I not only have a mantis that I've had no luck catching with the Mantis Trap but now I also have at least two crabs in the rock that I have seen. They have black pinchers and furry spider legs that are brown and stripped with tan color. I've not seen the bodies yet. Will the club soda dip work to rid the rocks of the crabs as well? Or is there some other way to rid the rock of these little beasts that will surely grow to kill any fish I add eventually.
<<A freshwater dip of pH / temp matched water usually makes these individuals exit the rock. Dumping soda water on there, yes, is another good way to get them to exit>>
I am to the point of adding fish and inverts but don't want to jeopardize any livestock to these guys. My set up is a 120g tank, a 30g fuge/sump, 150lbs of live rock, 80 lbs of live sand. Any advise would be appreciated. First time question writer but long time reader..
Thanks for all the help so far.
Mike
<<Hope the above helps Mike, regards, A Nixon>>

Gobies, Firefish, Jawfish- And a Familiar Ticking Sound! (Possible Mantis Shrimp?)   5/2/08 Good morning fishy folks... <Hey there! Scott F. in today!> It's been months since I last wrote you... so things have been running pretty smoothly I must say. Just wanted to pick your brains about two things... <Pick away!> I've had a pistol shrimp for a few years before finally giving it away due to the increasing hermit crab grave yard in my tank, so I am fairly familiar with Pistol Shrimps. Last November, within about a month of adding new liverock... I heard and quickly spotted a mantis shrimp and was able to catch him and trade him off for a feather duster at my retailer. <Hmm..I wonder who made out better on that trade?> Now, I am hearing a somewhat familiar sound coming from my tank and I haven't added liverock since October last year. I have 4 hermit crabs, a peppermint cleaner shrimp, a large coral banded shrimp, and some sort of 'rogue' large black Mithrax crab. The liverock that was added in October seemed to be crawling with sandy brown-legged black-shelled crabs similar to that of a Mithrax crab. Every so often they'd turn up dead washed out to the front of the tank by my wavebox. To my knowledge, I only have this one single LARGE (about the size of a Canadian $1 coin) crab. Anyhow, last night... the two shrimps and this crab were in the same corner of the tank in close quarters. I heard 3 large pops (similar to that of a Pistol or Mantis Shrimp) and the two shrimp and the crab scattered. <They must know something you don't, huh?> My question is... can a crab make this noise?? I am thinking not. I know the CBS and Cleaner certainly can't. I'm worried that I've potentially had another Mantis Shrimp unknowingly for months. I do spend quite a bit of time in my aquarium room and I'm surprised this would be the first I have heard it, if that is in fact what it was. <I suppose that it's not impossible for a crab to make this sort of noise, but I'm with you- I'm leaning towards a Pistol Shrimp or Mantis Shrimp. A nocturnal investigation into this is definitely in the future for you!> With respect to this large 'unwanted' crab... it seems to be content picking at the encrusting algae on the rocks, it leaves my mushroom and polyp corals alone, seems to not be bothering my much smaller hermit crabs or my fish (Two Percula Clowns, Kole Tang, Fairy Wrasse, Two Yellow-Headed Jawfish, yellow-tailed blue damsel. I do like this crab, but his size and the fact that I can't properly identify him makes me nervous that he is in my tank. He looks big enough that he could do serious damage to any of my Jawfish should he be interested. <My personal philosophy with potentially problematic inhabitants is "When in doubt- take it out!" Trust your gut instincts on this and don't wait for problems!> Of note, this is a 90gallon tank with 90lbs liverock, and a 4" sandbed... and the wavebox is an awesome addition! <A fabulous piece of equipment!> I also have a 24gallon nano-tank. I've been housing my rather large Yellow Watchman Goby in this tank solo. Recently I added more cured liverock bringing my total to about 30lbs in this tank. I also added a Blenny (Bicolor ?). The two have been doing well together over the past few months. The tank seemed to be thriving and I added some polyps and some Hammer corals that also seem to be doing rather well. About two weeks ago, I figured it was time to add the final residents, 4 small hermit crabs and two Firefish. I did have a concern that the Watchman Goby might be a threat to the Firefish, but the retailer whom I trust figured I'd have good odds with this combination. <I'd generally be quite comfortable with this combination, but I cannot say that keeping a "non-mated" pair of Firefish is always easy. It seems that one almost always takes out the other in a relatively short time.> I did not quarantine the Firefish as this 24gallon tank is really my 'extra' tank and gobies fair rather well to common disease and illnesses that may be presented by new additions. As well, I figured after reading... that the Firefish also were pretty resistant and I had been checking these Firefish out for most of two weeks at my retailers. <I have to voice my gentle disagreement with this theory. Just because a fish tends to be "disease resistant" is not a valid reason to skip quarantine. The fish could be a carrier for disease, or may simply contract a disease (despite it's "reputation") for any number of reasons. Why risk it? A simple quarantine aquarium is such an inexpensive investment and can provide numerous long-term benefits. At the very least, a quarantine aquarium gives livestock a chance to acclimate, adjust, and "rest" after the rigors of capture, transport, and handling between the reef and the local fish store. Please do consider embracing the practice of quarantine in the future! OK- off my soapbox now!> Within 48hrs of introducing the pair of Firefish, I was missing one and my watchman goby was acting strange. It kept taking mouthfuls of sand, moving it's mouth around, and then spitting the sand out. <Possibly, he/she was simply demonstrating territoriality...hard to say what this behavior meant.> Luckily, the goby was doing this right in front of the glass and I am about 90% certain I could see the missing Firefish in the goby's mouth. <Hmm...I'd be surprised if the fish was eaten by the goby. Rather, I think that the goby may have been attempting to scavenge.> The other Firefish was hanging out near the surface when the lights were on and was hiding at night. <Not an unusual behavior. These fish like to retreat to safe areas at night, or whenever threatened.> 5 days later, the remaining Firefish is laying dead on the sand bottom untouched. <Sorry to hear that.> I figured if the watchman goby was eating the carcass of the initial Firefish.... We wouldn't he feed on the 2nd one. Would it seem more likely that the goby caught the first Firefish? Anything seem strange here? This Watchman Goby is about 4" and thick and certainly had the capability to swallow these guys whole. <I'm sure that he is capable, and it's not an impossibility, but I would be a bit surprised to see this happen.> Ok, I lied... I have a 3rd question. <Two minutes in the penalty box for you!> My two Jawfish of medium and large size upon first introduction to my 90gallon tank last October shared accommodations for about a week and then moved to opposite sides of the tank. Just in the past two weeks, they have shared a very small hole and it seems almost like the smaller one is on the lookout catching food items. On occasion I see the larger one come out to feed. I coulda sworn I saw the smaller Jawfish actually catching food items and spitting it into the mouth of the larger Jawfish on at least two occasions. They seem to have a pretty cozy hole with just a single entrance that they close up at night. In your opinion, is this mating / nesting behaviour? Should I possibly expect to see little Jawfishes if I have the chance to witness before the damsel or fairy wrasse move in to make a meal? David Brynlund <Good question, David. These fishes do establish social hierarchies, so it is possible that they are simply settling in. On the other hand, if they are interacting in such a close way, I would not be surprised if you see some sort of spawning event in the future. Best of luck to you! Regards, Scott F.> Gobies, Firefish, Jawfish- And Familiar Ticking Sound (Cont'd.) 5/2/08 I totally agree with you on the quarantine tank... But this is, sort of my quarantine tank. I had no place to put my goby and I've had him for years... So I dressed the tank up with a sand bottom and liverock. My other tanks were fully stocked. Wife kept complaining that the goby looks so sad and needs some friends. I think of this tank as not a main display... But a extra habitat? I mean, it's still very easy to dismantle should the need arise. <Ok, let's call it a "semi-permanent feature". A true quarantine aquarium is bare bottomed, sparsely decorated, and broken down after use. If the fishes in this aquarium are destined to another aquarium after some period of time, it may qualify to some extent.> Ok, so first thing this morning I do my usual checking of tanks in the dark... With the flashlight. For my reef tank, I usually count my fish that tend to hide... Check out my shrimps that are always out and about in the dark... And I check for the whereabouts of the rogue black crab. However, this morning I see something tiny (almost un-noticeable... Like maybe 1mm) wiggling about... Is it some sort of small crustacean/brine shrimpy type thing? No, the wiggling thing seems to be attached to an arm and I notice orange and green and a body ducking quickly into one of the holes of the liverock. I scanned the rock with the flashlight for most of 20minutes noticing that there was something in there hiding from me. I didn't get a great look... But I trust my eyes and instincts that my 'better' look near the end would identify this as a fairly small 2cm mantis shrimp. Could be wrong, but I think it's there. I quickly removed the eggcrating top and pulled this large porous rock out immediately and placed in a bucket. I carefully poured cold fresh water into some of the pockets avoiding my polyp corals in attempt to flush the shrimp out into the bucket. Instead, I did get a small beige flat shelled crab (not anything like a Mithrax... Some sort of sand crab?). I'm pretty sure that's NOT what I saw originally and I do hope that I managed to lift the rock with the apparent mantis shrimp still inside. Finally, I was running late for work... I placed this rock in my 20g quarantine tank. DOH! You busted me... Yes I do have an additional quarantine tank... Should my polyp corals be ok in a quarantine tank with only 60watts of lighting on it... Even if it is for a day or two? I hope to be able to spend more time and flush out this mantis. Any suggestions? David Brynlund <Well, David- I think that you might be on to something here! As another alternative, I'd consider removing ALL the rock and possibly desiccating it for some period of time. Yes, there will be "collateral damage" to the life forms on the rock, but the Mantis (if present) will be history. You would, of course, remove any corals on the rock first. If you opt to keep the corals in the QT, you can compensate for the lower light by increasing feedings. Best of luck! Regards, Scott F.> Gobies, Firefish, Jawfish, and a familiar Ticking Sound (Cont'd.), Mantis  5/6/08 To clarify... This is the only rock in this particular glass bottom tank. If I held the rock so the bottom was just touching the water level... Would the mantis shrimp eventually seek the water vs. sitting in the rock without water? <I believe so!> How long could the shrimp survive out of water? <I'm not really that sure. I think it would definitely seek the water at some point to avoid desiccation> What about the corals? <Many corals are subject to tidal fluctuations and can be out of the water for surprisingly long periods of time. I would not recommend this for captive specimens, of course. Better to remove the corals from the rock before trying removal process.> Any other tips or tricks? Power heads directly on the rock etc? David Brynlund <I've actually heard of people submerging the rock in club soda, and other exotic stuff. Other possibilities include putting the rock on a platform of eggcrate, and baiting the shrimp with meaty foods. DO look on the WWM site for some different takes on getting these pests out! Good luck! Regards, Scott F.>

Re: Jawfish Burrows... Stomatopod extraction
Good morning Mich,
<Good day David.>
Not a question today... Just an update.
<Ok.>
Two round goldish eyes on stalks peering out at me from a hole in the liverock conveniently in the front right corner. I has me a mantis shrimp! (excellent grammar, hey?)
<Heehee! I've heard/read worse... that was unintentional to boot!>
Anyhow, I didn't want to scare this guy off... I used a piece of glass from my tank top and cornered him off in about a square foot of tank
space. He hung out in the liverock that I quickly placed into a bucket.
I was quite impressed... 2 min.s to catch a mantis shrimp.
<SWEEEEET!>
The guy that owns the aquarium down the road LOVES mantis shrimp, so I was able to exchange this 2" little dark green guy for a large Hawaiian Feather Duster.
<Perfect!>
I also noted some Mithrax like crabs. Glossy black bodies with beige/browny hairy legs. The body is about the size of a nickel. Anyhow, the guy at the store told me to get rid of them... Called them 'gorilla crabs'?
<Yikes!>
Anyhow, it seems like WetWebMedia's stance on 'unknown' crabs is to not take a chance? Get em out?
<Yes, many/most are opportunistic predators. Perhaps a new home in the refugium?>
I do think the mantis shrimp was killing a few of these guys... Because there are sizeable crab claws here and there...
<Yikes!>
David Brynlund
<Glad you were able to find and remove the mantis! Good luck with the other crabs. Thank you for this update and sorry if I steered you in the wrong direction at any point along the way. Mich>

Mantis Shrimp Problem? 10/8/07
Hello Again Crew
<Hello>
I have a Mantis Shrimp problem and I was wondering if you could help me out with. I bought 100 lbs of Gulf Live Rock a month ago. I have it all in a separate tank curing and QT with no fish. Rock is full of life and color. Problem is I started hearing clicking and then I saw them. I searched your site and it said club soda squirted in his hole. Worked great and one came right out. Now the others? Not sure where there hiding? If I go buy a bunch of club soda and pour it completely over the rock one piece at a time will it harm the rock?
<Is irritating, may harm some animals if not rinsed with salt water after the procedure.>
We took every piece out once and squirted club soda in all suspecting holes but we have only caught two so far. I know there is at least one more. How dangerous to fish are these guys? I read on your site people losing fish to them. Will mantis go after large fish are do they just eat fish smaller then them?
<Whatever they can catch, but unlikely fish larger than the shrimp.>
I read somewhere triggers are good at eliminating them. I bought a tank July 4th with live rock used and I think there's one in there also. I never heard any clicking till a week ago but have never lost any fish. My coral banded shrimp did lose an arm but grew back in 2 weeks. Not sure if that was the mantis are not.
<Could have been, they will go after inverts also.>
I have never seen him once. I would like to start putting the rock in my main tank but don't want to get any of those critters in it.
<This clicking you hear may also come from a Pistol Shrimp, much less dangerous than the Mantis and relatively safe in a reef system. You may want to buy a Mantis Trap, bait it, and see if you can get the critter that way.
Do read here and linked files above for more info on this shrimp. http://www.wetwebmedia.com/marine/inverts/arthropoda/stomatopods/mantisshrimp.htm>
Thanks Crew
<You're welcome. James (Salty Dog)>
You Guys Are Great

Elusive predator, SW  – 09/08/07
Good morning. I have been making an ongoing effort to locate/catch/remove an unknown predator from my tank. I have read and tried several techniques discussed in the WWM FAQs, without success so far, and am becoming increasingly frustrated.
Recently, a six line wrasse turned up missing. One of those "here last night, gone this morning" kind of scenarios. It completely vanished without a trace; no corpse, corpse fragments, or bones. I checked a 4 ft radius around the tank, and did a visual inspection of the sand, rock crevices, skimmer, etc. No sign of anything. I have not had anything this strange happen before, and I kind of let it go for the time being.
About a week ago, a second disappearance occurred, of a royal Gramma. Same exact situation as I described for the wrasse. Of course, after a second disappearance within a few weeks, I became extremely concerned and set out to figure this out.
I think that, in light of the nature of the situation, I am definitely dealing with a nocturnal predator. These two fish were in excellent health, very active and eating well immediately prior to their vanishing acts. Water parameters are checked twice weekly and water changes are done twice weekly.
Current key parameters are sg 1.026, avg. temp 80, pH 8.2, nitrates 5-10ppm.
I have not seen
<Nor heard?>
any uninvited guests in the tank, but I have to suspect a mantis here.
<I as well>
Over the last 8-9 days, I tried inverted water bottle traps, front-corner-of-tank raw shrimp bait with net ready, scanning the tank at various times of night with a flashlight, to no avail. In my case, the traps are just catching snails. Last night, I was very frustrated and just sat there staring at the tank, wondering what to do about this. For the first time, I started hearing faint clicking noises;
<Faint? Perhaps an Alpheid, or decapod...>
the noises were consistent with the "marble on glass" analogy that has been mentioned a few times by others who have asked mantis-related questions.
It seemed to be coming from one of two large rocks, so I quickly pulled them out and submerged them in a bucket of club soda. About a dozen worms came out immediately, but no mantis or anything else. The second rock produced similar results.
<A swing and a miss>
This morning, I *believe* I heard more clicking sounds, so I guess it's still in there (maybe I'm just starting to imagine things now, though). At this point, I'm considering a full tank breakdown, throwing all the LR and LS away, and starting over.
<Mmm, a bit extreme... I'd soak in FW or dip in Club Soda, or such...>
I guess I could do sequential FW dips on every piece of rock, but I will end up with mostly dead rock anyway after doing that.
<Mmm, not really... the vast majority of life will/would survive. Worthwhile>
Since the "spearer" type mantis are the ones who typically victimize fish, and they normally build burrows, should I start raking through the sand bed and try to find it?
<Mmm, yes... w/o the LR present>
I know that a DSB should not normally be disturbed, but I'm hitting a brick wall here.
Any other suggestions on how to "sensibly" proceed from here would be most appreciated. Sometimes when I become frustrated, I tend to act impulsively; I want to make sure that I handle this in the best way possible. In addition, I feel that I could be chasing the wrong target...maybe it's not a mantis, and it's something else, since I haven't visibly "seen" it. I have quite a few Zoa and LPS frags in the tank, and a DSB, so that's going to be a major project if I have to do a full breakdown. However, with two deaths so far and more inevitable, I know I must take any actions necessary.
Thanks,
Matt
<I suggest a systematic approach of removing all the LR... running sequentially as you state... and if not finding a/the predator/s, combing the substrate in turn. Bob Fenner>

Mantis Shrimp Removal - Thank you Bendy Straw!- 7/21/07
To Bob and the rest of the gang,
<Hi Jason!>
First off, thanks! <Anytime!> I've been going through what appears to be a rather
common occurrence: snapping noises in the middle of the night, fish, crabs, shrimp and other desirables mysteriously disappearing, etc. <Ah, yes> I'm fortunate to, at least currently, live in Hawaii. <Yes, indeed!) I have a collection permit and catch
all my own stuff, so I haven't actually bought a fish in years. <Wow> Losing fish wasn't costing me any money but was really disheartening. <Undoubtedly> I've suspected a mantis shrimp as the culprit for a while now, but until today was completely unable to find it. <Happens a lot with these guys> This morning I did notice two small stalked eyes looking back out of a small hole in a rock, and finally found the little bugger's house. <Heeee! Good work!>
I searched your site and read and considered all the options. <Great - always good to hear!> My Snowflake eel is the only one not bothered by the mantis. Unfortunately the eel never bothered to eat the mantis either. <The mantis could have been a little too big for the eel, and/or the eel tried to eat it at some point, but was strongly “discouraged”!> They've been in the same tank for a year now and no joy. <With the possible exception of the mantis!> Maybe if the planets aligned just right <LOL Would that also include the new dwarf planets?> and motorcycles had doors, this method might work...<Heeee!> Anyway, I was able to quickly remove the rock into a bucket with tank water in it and still have my fingers and thumbs in working order. <Good to hear - mantis shrimp can do some damage! If you don't already own a pair of gloves, you might want to consider purchasing some.> I didn't want to kill any of the feather dusters in the process so soaking the rock was not really an option. <Understandable> I found one of my kids' bendy straws on the counter and a cold can of 7-Up in the refrigerator. I filled the straw with 7-Up and put the angled side of the straw down into the hole. The soda went in the hole and the mantis immediately leaped out of the hole and into the bucket. <Maybe he didn’t like the new improved formula> Total elapsed time from removing the rock from the tank, to replacing it, was about a minute. <Nice work!> Of all the options presented, I back the soda water. <I can see why. It certainly did the trick - and quickly! The only thing I would add is that my first choice of soda would have been something like an unflavored seltzer, but hey, sometimes you have to improvise!>
The mantis is in a cup (the one that the bendy straw came from) with tank water and a lid. Know anybody who wants a mantis? ;-0
<Actually, there are people out there that collect these guys! They’re fascinating little creatures, but they sure don’t belong in a mixed reef tank! You might check to see if there’s a club in your area. Someone might just love to adopt that little mantis!>
Again, many thanks for sharing your expertise with the rest of us.
<Many thanks to you as well, for sharing this with us, and good luck! –Lynn>
V/R
Jason Geyer

Bad mantis, removal tech.  7/21/07
Hey crew,
<Matt>
Thx for your informative website-it's helped me out a great deal! I have a mantis shrimp problem-however his behaviour is very unusual. He RARELY comes out. I have had the tank for 18 months and I've seen him twice. Therefore I have no idea which rock he resides in. He's smashed his way through 11 of my 12 snails, all of my hermit crabs, and he's also recently devoured my prize flame hawk, partly due to my ignorance :( (everyone told me he would EVENTUALLY get my fish and I was like "yeah whatever").
<Whenever>
Anyway I was moved to make a trap out of a coke bottle. He managed to get the piece of bait out without getting caught. So now I want to try the 1.036 sg salt dip. I just want to know if this will kill my coralline algae. If so, I'll try something else to get him out.
Cheers!
Matthew
<I would NOT raise the spg. in the main tank of course... but the elevated spg. should not kill all the coralline... DO wear gloves and watch your hand while systematically removing all the LR here. Bob Fenner>

Mineral Supplement Use/Misuse On Small Systems...And a Mantis Shrimp Too! - 05/11/07
First I would like to thank you for keeping all of this great information out here and available.
<<Quite welcome...  Tis a collective effort>>
I am new to the hobby, as I am sure you will be able to tell, so I have been a bit shy about asking questions for fear of asking something really stupid.
<<No worries mate...we were all beginners at one time>>
But I need some expert input, so here goes.  I have kept a 24 gal. AquaPod system for about 9 months.  Here are the stats:  ammonia and nitrates stay at near 0, calcium stays at around 460 ppm,
<<A bit high...400ppm is a safer level>>
KH/alkalinity fluctuates between 9 and 11 dKH,
<<Mmm yes, definitely need to let the calcium level drop.  Read here and among the links in blue at the top of the page (http://www.wetwebmedia.com/calcalkmar.htm) >>
pH (my biggest headache) fluctuates between <8.0 and 8.3.
<<I see>>
Tank inhabitants; two Ocellaris Clowns, one Green Chromis, one Firefish, Blue Leg Hermits, and various snails.  I also have one struggling stalk of Xenia, a less than thriving colony of Yellow Polyps, 5 Ricordea and some Blue Mushrooms.  I started the tank with 10-12 lbs. of live rock and live sand (one bag, weight unknown).  Tank maint: 10% water change weekly, filter media rinse in old tank water monthly, 4 drops of Iodine daily, Calcium every other day, Essential Elements and Strontium & Molybdenum weekly.  
<<If not already, you need to be testing/verifying a definite need for these additives.  Considering your livestock, the 10% weekly water changes should be providing all the earth/bio-mineral elements your tank requires.  Possible overuse here may well be what is causing your pH fluctuations>>
I have been using Kent marine products, adding a capful of liquid Pro-buffer dKH every other day.
<<And again...not needed/likely problematic on this system>>
If the pH rises to 8.2-8.3 I try to reduce to once every 3 days, and it drops to 8.0 or less again.  Once it drops it takes daily doses, sometimes twice daily, to get the levels up before the Xenia die.  My LFS has advised to add a full dose (1 capful based on my tank size) to new water before adding, which I do, using Red Sea salt, which didn’t help, and most recently switching to Seachem products.
<<Yay!  A much better product choice in my opinion>>
They advise that I should only have to add dKH twice a week at most.
<<Not even then...>>
Can you offer any additional advice as to what I might be doing wrong/not doing at all that would require me to add buffer so frequently?
<<I can...see below>>
Or is it normal in this size tank to have to dose so often?
<<It is not "normal"...and is often problematic as mentioned.   As you will discover reading from the links I have directed you to, “high” calcium and alkaline levels tend to be mutually exclusive (the “marble analogy” will make this clearer).  The supplement additions you are making to keep both at the upper end of the spectrum are driving one or the other down; depending on what is being added, which causes a dangerous seesaw effect. And at worst, will cause a precipitous event where both calcium and alkaline buffers fall out of solution in what looks like a snowstorm raging in the tank.  My recommendation is to stop these supplement additions...perform several large water changes (as needed) to bring your calcium and alkalinity back in balance...and rely on a larger water change done less frequently (25% every two to three weeks) with water that has been allowed to mature/complete its chemical processes and see if this doesn’t help to bring some stability to your system.  Do browse our FAQs on mixing artificial seawater for info and tips on buffering/maturation/storage/et al>>
My other question is regarding a little guy that I found in the tank about 6 weeks or so ago.  When I first saw this critter I thought it was some kind of worm.  It looked like a small green caterpillar, and would dart out from the rocks to grab Mysis shrimp that the fish had missed.
<<Cool!>>
I searched everywhere to find out what it was, and found nothing.  Last night I got a better look at his head and tail, and I am nearly sure it is a small mantis shrimp.
<<A good possibility...and very neat creatures too>>
On one of your boards, among all the horror stories of fish death and tank destruction, I saw in a response from Anthony that there is a small green mantis that remains <2 inches and is relatively harmless.
<<Ah yes...and even some of the larger species can be “relatively” harmless if kept fed and the hobbyist is careful with selection of tankmates.  But regardless of size, if you really want to observe and enjoy this critter then consider a specimen tank just for the mantis>>
The one in my tank is a greenish color, and has been about the same size (app. 1 inch) for at least 6 weeks or so.  Can you tell me how fast these creatures usually grow?
<<Hmm, not really...but would think 6 “months” to be a better gauge of size potential>>
I am hoping he has reached maximum size, and can be left in the tank with current inhabitants.
<<Time will tell>>
Thanks for any info or advice!
Debbie Weeks
<<Is a pleasure to share.  Eric Russell>>

Mantis Mob – 5/4/07
Good evening crew, thank you in advance for your knowledge I really appreciate it.
<We hope we can be of help.>
I recently cured (about 2 months now) 90 pounds of Tonga live rock in my newly set up 75g tank. Now that my water quality seems quite good all the critters that made it through the toxic hell fresh rock generates are showing themselves. There is a featherduster, several snail looking things (I don't think they are snails they just resemble them), some sort of mollusk, pink, green, red, purple, crimson, lavender coralline, oh! and about 2-3 dozen mantis shrimp running around the tank, uh-oh!  
<Eek!>
The shrimp are small (from tiny to about 1/2 inch in length) and aren't a problem yet but they will be. I don't have any fish in there yet, I want to take my time and research which fish to get plus see what grows out of the rock. I have read the mantis faq's and have seen some ideas like freshwater and soda water dips, turkey basters etc... but I don’t want to lose my other life in there. I read about making traps but there are so many and so small it would probably take months. Is there a certain fish that will feed on them exclusively that won't cause problems down the road? Or some other natural predator that will eat them while they are small? any ideas?
<There is some good reading here:
http://www.wetwebmedia.com/marine/inverts/arthropoda/stomatopods/mantisfaqs.htm
The episodes about the “Siege” are particularly entertaining, and have a good description of a DIY trap by Bob.  Several mention a Snowflake Moray as a possible predator, but I doubt that this would be thoroughly successful and would worry about the Moray getting hurt trying to eat such tough critters.  The best thing is to trap them.  Since there isn’t a lot in there for them to eat, they should be hungry enough to trap.  If you want to remove them, best to do so before you stock it anymore.  Since you plan to wait to stock up, this is the perfect time to trap.  Try different traps and bait, you will knock them out soon.>  
Anything will help, thank you so much for your help. P.S. look forward to seeing the WWM crew at the IMAC Chicago in June.
<See you there!>
  Thanks much, John P
<Welcome. Alex.>

The Incredible Invisible Mantis Shrimp - 04/28/07
We are baffled.
<<No worries...most of the time I am as well [grin]>>
About 3 months ago, our fish started disappearing.
<<Troubling indeed>>
We assumed it was a mantis, based on a clicking sound and the outright disappearing fish (no corpses, no nothing).
<<Sounds like a logical assumption>>
Ultimately, what has disappeared:
-a pair of Percs, a royal Gramma, a firefish, and a bicolor blenny :(
-a peppermint shrimp
-countless hermit crabs
<<Does seem to point toward a Stomatopod>>
In the middle of these shenanigans, I moved to South America for a semester, leaving the mess in the care of my boyfriend.  From my long distance research, I confirmed it was a mantis as well.
<<I see>>
But now we're not so sure . . .
<<Oh?>>
At this point there are NO fish left in the tank.  BF has searched high and low for the shrimp.
<<Not really a "shrimp" ya know...>>
He bought a commercial trap that never worked.
<<These critters are very intelligent/learn quite quickly to avoid such contraptions...usually if you miss on the first shot, that's it for that method>>
Last night, he tore apart the tank, taking each rock and squirting it with soda water.
<<Mmm, likely ineffective as well...would need to submerse...>>
He ultimately left most of the rock exposed to air for quite a while, so everything is probably dead on the rock anyway, but the conclusion is:  He found no shrimp, no evidence of any of the fish, no sand caves, no nothing.
<<Doesn't mean it's not there still yet...dead or alive>>
At this point, the rock is in buckets (with tank water), and we're planning on re-cycling the tank and starting over.
<<A very good idea>>
But what's the point if there's some unknown predator?
<<A valid concern>>
Any thoughts on what ELSE it could be, or what we could do here?  I don't want to get rid of all this rock, as we know it's very pricey.  Specs: 29 gallons, maybe 45# live rock, 1" sand bed. 2-3 hermit crabs.
<<I'm still of the mind that the culprit is a mantis shrimp.  Since it sounds like this rock is not much more than "base" rock at this point, you could try "submerging" each rock in soda water to drive the Stomatopod from it's hidey-hole...if it is even still alive after the previous squirting/drying out...or give the rock a "freshwater soak" of a "few days" if you think there is still a danger...and then let the rock "cure" in seawater for some weeks before reuse.  Regards, EricR>>

Removing hoards of mantis shrimp  – 03/09/07
Hi,
<Jed>
My question is short and simple, yet I am still unable to find a reasonable answer. So, here it is. I recently got a colony of zoas attached to a baseball sized piece of liverock. The problem is that the rock and now my qt tank are infested with what appears to be dozens if not hundreds of tiny mantis shrimp. The largest of them are about a half an inch long and are brownish in color. I have elevated the zoas on eggcrate in an attempt to trick the shrimp from leaving the rock and then being unable to get back up, but they do not seem to have any trouble scaling the eggcrate platform to get back to the rock. I have tried trapping them, but that only removed some of the larger shrimp. So far the zoas have been in my qt tank for 6 weeks and I would like to put something else in it soon. At their present size I do not think that they pose much of a threat to anything, but they are still not something I want in my display. So what would be the best way to eliminate the little tiny shrimp which make my qt tank sound like a bowl of rice crispies with all the snapping, crackling and popping? Thank you for all that you do to better inform us, your efforts do not go unappreciated.
Jed
<Likely a small predator... Maybe a Toby, Canthigaster species. There are chemical means... e.g. organophosphates... but I would not avail myself of these here. Bob Fenner>

Mantis vs. pistol shrimp (ID, not in the ring) 1/26/07
Just a quick question.  
<Hehe, I've seen that once or twice...>
I believe I have some sort of large crab or shrimp in my nano.  I have the clicking sound....very distinctly sounds like a heater popping against the tank side.  It happens often, but not in rapid succession.  (not the heater - I checked)   I have seen a largish crab type thing.  It is bluish, brown leg type things and hides enough I cannot tell anything more.  I don't think it is a hermit, unless it has forsaken its shell for a large piece of hallow live rock covered in zoo's and grown incredibly large.  I moved this rock from my main display to the nano a few weeks ago since I sold my big tank.  While breaking down the large tank I did notice an absence of all hermits and all but the largest snails.  I also had periodic disappearance of chromis.  Do you think this could be a mantis or pistol or maybe something else.  The nano only has zoos, mushrooms, and a toadstool  It has no fish, but 2 large mated CB shrimp I have had 2 1/2 years.   Would the mantis kill the shrimp or visa/versa...?  
<Oh, god YES! If you think you have a mantis, you need to remove him from that mated pair ASAP!!! You need to confirm your suspicions by looking at some pix of mantis shrimp on google or here.>
They have so far coexisted for about 3 weeks and the nano is only 12 gallons. I don't intend to have any fish, could this just stay?
<I will never recommend keeping crustaceans in a system with a mantis shrimp. Bad bad idea.
-GrahamT.>

Mantis <Removal> issue   12/8/06
Hello,
<Hi there>
I have a real issue with a mantis shrimp that come with my tank.
History:
My 215 G tank has been running for 1 year and all 280lbs of LR came from an established tank of 8 years.
Inhabitants:
1 pair of GSM
7 Chromis
1 sixline wrasse
3 GBTA
1 desjar
2 Cleaner shrimp
2 Pepp shrimp
1 Fire shrimp
50 hermits
<Surprising that the Stomatopod hasn't consumed these other crustaceans as yet>
I have a mantis that I have never seen but heard. He is a hammer type based on all the broken shells.
He has killed:
150 hermits
6 peppermint shrimp
4 Turbos
1 Naso
<Wowzah!>
The following methods have been tried:
1) Mantis Trap
2) Pantyhose
3) Bottle trap
4) Tried to pull his rock
<This last may need to be done... in earnest>
I am at my wits end and ready to tear all the rock out and start over again <I would plan on this...>
but want to ask questions before I move on.
1) I wanted to add an either Pink Face Wrasse or a Banana Wrasse to see if they will take care of my mantis
<Not likely, no... if this animal is entrenched, of size... the opposite is more likely>
2) I have thought about a few methods/Introducing another mantis in a hamster ball as a trap to get him out,
<Neat!>
is there some thing that I can add to the tank that will get him sick or stressed?
<Not that wouldn't be more trouble for your other livestock...>
3) What about adding a snowflake eel?
<Nah>
Thank you for all your time,
Russ
<... make it a pilgrimage Russ... get out all your largest containers... help from/with friends, perhaps the local marine club... systematically remove all rock, water, other livestock if necessary... if you have large pieces of rock... squirt simple "soda water" to "flush'em out"... and do keep close watch on where your hands go... Bob Fenner>

Porcelain Crab vs. Mantis Shrimp. No Contest   11/23/06
Hi crew
<Hi Kerryn>
I've found your site very helpful with a lot of my questions on marine tanks, just a new comer to the marine world now having my tank running for a year, have made all the mistakes but I've learned by them as well, but one problem I can't solve is a with an anemone porcelain crab, I have searched the net for hours trying to find the answer. I have two anemone porcelain crabs that live very happy in an anemone each, one had a green algae forming on the top of its body, I thought this was a normal process maybe the crabs shell was getting old and was ready to shed, but obviously not, I woke up this morning to find him on his back in the middle of the tank, I did find some information about a disease that forms on a porcelain crab but didn't mention what it looked like?
I do have a mantis shrimp cutting about in the tank, I can see a nip out of the crabs claw its black around the wound, I don't know how long the wound has been there,  it's known that they will shed a claw or leg if threatened, everything is running brilliant in the tank, temp is 24 to 25 degrees, would really like to know what happened to it I've only had them two and half months-ish.
<I'm surprised they lasted that long with that "Hit Man" you have in the tank with them.  Mantis Shrimp belong by themselves and will kill, dismember, and eat crabs, shrimp, etc. along with smaller fish that it can sneak up on during the night.  He is going to have to go or the other crab or a fish will be next.>
Cheers
<And to you, James (Salty Dog)>
Kerryn.

Mantis issues   10/2/06
Hello,
Thank you for the wealth of information which your website offers, it has helped me immensely.  I've recently determined that my tank is inhabited  with one or more Mantis shrimp.  I get the familiar popping noises at night  which had baffled me for a while.
<Mmm, or could be Alpheids...>
I've lost 5 fish over the past two  months since I introduced some large pieces of live rock.  Two of the fish  I lost were of fairly good size.
<Oh...>
One was a Lawnmower Blenny of about 4  inches.  The other was a Fairy Wrasse of about 3.5 inches.  The Wrasse  had been found alive wedged in a crevice of some branching live rock.  I am  curious what you might think about this.
<Time to go Stomatopod hunting, removing>
It was quite a struggle to get  the Wrasse out of its position, and I ended up ripping it out with tweezers which  killed the poor thing.  
Could the Mantis have done this?
<Mmm... yes>
Or do fish  typically get stuck in rocks to where they must be ripped out?  
<Nope... no species-survival value in such behavior, eh?>
I also  wonder if my Blenny was killed by the Mantis or if it is possible/more likely to  have gotten stuck in a rock like the Wrasse.
<Highly unlikely>
I set up a trap using a small  plastic water container, cutting off the end and inverting it into the container  with a piece of mesh rubber banded around the mouth.  It's been a few days  with two of these traps baited with krill and still no luck, although I think I  heard a Mantis thumping on the plastic.  Any advice/help is greatly  appreciated.
Sincerely,
Chris
<Time to use the all-plastic re-labeled mouse-traps in my estimation. Bob Fenner>

Mantis Shrimp Hitchhiker...What To Do? - 07/23/06
Greetings Crew!
<<Phil>>
Well, it appears I might have a mantis shrimp lurking in my tank, which is approaching a year old.
<<Neat critters>>
I have had a number of hermit crabs mysteriously turn up eviscerated over the last 4 or 5 months.
<<I see>>
Originally I though it might be the olive snail burrowing through my substrate, but even after I returned him, the carnage continued.  On a couple of occasions back then, I though I heard the notorious clicking at night, but it was not frequent and seemed to disappear for a number of months.  Within the last week, I've heard it again after dark on several occasions and today I think I might have located the rascal.  I noticed something spewing gravel out of a small lair, and eventually it even showed a part of its body.
<<Making itself right at home, eh?>>
It was tan colored with darker stripes traversing its body.  However I only saw what I believe was the forward part of its body; it appeared to be somewhere between 3/16 and 1/4 inch wide from what I could tell.
<<Relatively small species then...likely of little concern, other than to your snails/hermits, etc.>>
If it is indeed a mantis, what would be the full length of his body if his carapace was 1/4" wide?
<<Hmm only guessing here, but I'd say 1.5" or less>>
I presume my hermits and snails will be in peril while he remains in the tank.
<<So it would already appear, yes>>
I'm guessing my fish (maroon clown, blue cheek goby, coral beauty, Foxface, bi-color blenny, 2 damsels) are relatively safe, however I am wondering whether he may develop an appetite for my new T. Crocea?
<<I don't think this is likely...especially if you manage to keep it fed with the occasional snail/hermit>>
I am somewhat of the philosophy to not intervene too much in what happens in my tank, assuming I am providing a somewhat stable, quasi-healthy environment for my charges.
<<Not to mention the behavior/antics of the mantis shrimp are in themselves interesting/to be enjoyed>>
However, I would definitely draw the line at the loss of my $80 clam.  What would be your opinion re the risks of leaving this hitchhiker versus removing him, and if I were to remove him, what is the method with the best chance of success.
<<I think the risks of leaving things be is small.  If you decide to remove, a baited trap (some are commercially available) or locating/removing the rock called "home", with a subsequent freshwater dip to drive the mantis out of hiding>>
And if I remove him, would it be unethical to 'terminate with extreme prejudice'?  I don't really have the luxury of setting up a species tank for him.
<<Why not trade to your LFS?  Someone would surely give it a home>>
Regards, Phil
<<Cheers, EricR>>

Peppermint shrimp and porcelain crabs... and Mantis and Clowns  7/18/06
Hi..
<Hello there>
I have a 55 gallon display tank that is being left fallow while my fish reside in a QT tank. I am well aware of the dangers that mantis shrimps
pose, and I know that one lived in my tank because I often saw him and he killed my coral banded shrimps. Now, I have not seen the mantis shrimp for
over a month and I no longer hear the clicking noises they make.
<... may be nothing to "click" about (live food items) present>
As an extra precaution I added some feeder ghost shrimps into my tank and they show no signs of being attacked.
<Oh! Good move>
Is it safe now to add 2 peppermint shrimps? My tank has plenty of live rock and hiding places.
<Only trying can/will tell>
Also, I had an anemone crab that was kicked out of the anemone by my pair of very aggressive tomato clowns. He lost about 6 of his legs and disappeared.
<Yikes, hopefully the legs will regenerate in a molt or three...>
Now that my tank is devoid of fish, I was thinking of adding a pair of porcelain crabs. If I let them live in the anemone for 3 weeks before I put
the pair of clowns back in, will they co exist within the same large anemone?
<Again, only experience can tell...>
Or should I get another anemone so they have one each?
<If this system is "large enough" this might work... It is not altogether improbable that the Clowns will "hog" all anemones...>
Thanks for
your help.
A
<Welcome. Bob Fenner>

Mantis Tactics Refined... and sponges   5/26/06
Greetings Crew:
<B in B>
On WWM there are many FAQs on how to rid a tank of a mantis shrimp.  I am thankful for that.  I have removed one using a new technique, and will be happy to send to you the details should you desire.
<Please do>
Meanwhile, I have two others that have evaded capture for 8 months now due to the size and complexity of my live rock.  At this point, I need help from someone with an intimate knowledge of marine life, and would greatly appreciate your help.  Questions; 1) If I submerge a piece of live rock into fresh water for the 5 to 10 seconds reported in your FAQs, should the fresh water be heated to match the temperature of the tank?
<Approximate is fine>
2) The rocks of concern have turkey wing bivalve mollusks, cup coral, tube coral, coralline algae, hydroids, chicken liver sponges, button tunicates, barnacles, copepods and small stationary dendrochirote sea cucumbers.  Which if any of these will likely die from the brief exposure to fresh water prescribed for the mantis?
<The sponges will likely suffer... If these are not held as particularly desirable, I'd scrape them off during this process>
I have tried, for 8 months now, to get these shrimp using traps and other methods, so I truly appreciate any help you can give.
Sincerely,
Brad in Basalt
<Be chatting, Bob Fenner>

Super salinization shock to drive the 'uglies' from uncured live rock ?   5/9/06
Hello Crew...
<Howdy>
Been reading, researching on starting a new DSB/LR aquarium and saw several tantalizing references to using a brief dunk of super salinated water to drive the hitch hikers from live rock. The snippets I found referred to salinity levels of 1.035-1.040
<Or even higher...>
but were frustratingly brief in their description of the actual process.
<Okay>
Here is my working hypothesis:  given receipt of 30 pounds of uncured Laho live rock from DFS each piece should be individually placed in a container of salt water mixed to a salinity of 1.040 (or there abouts)  and within a couple ( 3 ? 5 ? 10 ?) minutes all the mobile hitch hikers hidden within will 'abandon rock' due to the haline stress.  The 'purged' rock can then be rinsed in fresh water briefly (1 ? 3 ? 10 ?) minutes and installed in the *uncycled display tank*.
<Should work... I'd use the ten minute marks>
Critters in the super-salinated container can then be triaged with acceptable beasties added to the aquarium and the 'uglies' consigned to the compost heap.
<One way of putting this...>
This theory appeals strongly to my sense of how marine invertebrates will react to a potentially deadly environmental stress with over-saturated salinity, but lacking any experimental reports in the published literature or practical empirical experience I thought it might be a good idea to solicit the salacious comments of the widely-acknowledged "Crew of Last Resort" !
Thanks...
John
<Was hoping for first place... Well, this protocol/procedure will likely result in a loss/removal of most pest worms, and crustaceans... with a good deal of the sessile invertebrates left alive... Bob Fenner>

Mantis Question  9/21/05
First of all, thank you for the site.  No other source I have seen offers as many facts and opinions for this hobby all in one place.  
<Great place isn’t it? I’ve learned a lot myself here. Adam J with you tonight.>
I have a new (roughly 4 month old) 30 gallon aquarium with about 42 lbs. of live rock.  My wife discovered a very small Mantis shrimp excavating his home in one of my live rocks.
<Uh-Oh.>
  We have seen his eyes and possibly the first fifth of his body length and from the pictures seen/articles read; I would estimate his total length to be 1" to 1.25".  
<That’s still large enough to wreak havoc on smaller invertebrates and fish such as snails and gobies.>
Is it possible that this specimen could lead a happy life in my tank without causing too much horror?
<Possible but in my experience not likely>
Feeding this guy small pieces of fish has already provided much entertainment.  
<They are cool animals in their own right and make great displays in species only tanks.>
I currently have several snails, 2 peppermint shrimp, 2 porcelain crabs, and an emerald crab.  I have not yet added the first fish but I was hoping to add at least one of the smaller gobies that are less than 1" such as the Trimma (sp.) goby.
<All of these could be a risk.>
My LFS has agreed to take him if he is not "ugly" and I manage to catch him.  The trap I purchased has not yet worked and I refuse to use any spearing or cutting technique (he didn't ask to get thrown into my tank).  
<I admire your respect for the animal, it will take patience but I would remove him.>

Mantis Still on the loose  9/28/05
Thank you for your advice.
<Anytime, that’s what I’m here for.>
After reading your response as well as all the literature I could find, I
decided I was deluding myself that I might be able to leave the little Fellow in a reef tank.
<Every once and a while I hear stories of people keeping a Mantis in harmony with other critters, though this is an EXTREME exception and not at all the norm.>
After having zero luck with a commercial trap, I decided to try the
RO/carbonated water method where each is poured over/into the rock.
<Ok.>
While I had read this is the "magic bullet" the stubborn fellow refused to
budge even after I went so far as to immerse the rock in RO water.
<They are very resilient critters. Keep in mind most of them that are found in tanks have survived dry shipment and curing. I even know of a specimen that survived a copper treatment.>
I am afraid that I pushed the limits and caused the death of the loan coral I had on the rock, an anthelia polyp.  This was the first coral I have tried to keep and it was doing wonderfully.  Though it was my fault for pushing the
limits on the polyp's exposure this experience has pushed me much closer to becoming a "mantis hater".
<I can imagine that this is a frustrating ordeal.>
My question is this:  If I did indeed kill the only coral on the rock, how
long can I place the rock in RO water without losing all the properties that make it "live rock".
<Personally I would not immerse the rock longer than 15 minutes. I usually shoot for around 5.>
After the loss of the coral, I will remove the rock
Permanently if that is what it takes, but it is a rather attractive rock
almost covered with purple coralline algae and I would like to keep it.
<It will take patience. I would try another trap or retry the one you have; sometimes it takes weeks before they work.>
Thanks, Eric
<No problem, Adam J.>

Re: Mantis on the loose ... no more   5/9/06
Greetings Bob,
<Jason>
Thanks for the great advise.  I pulled out each rock last night and dipped them all in fresh water for two minutes.  After it was all said and done I
looked through the water and found at least 20 little Mantis shrimps in the bucket.
<Yikes!>
( they were about 1/2 cm in length and a bluish/green in color)  Just seeing all of them there makes me wonder if there are more or
not but hopefully I got them all.  Once again thank you for your advise! I really appreciate it!  Now there is no doubt in my mind that I can
continue with the tank the way that I intended it to be.
Thanks for all your help!
Jason Chernick
<Congratulations on your "fishing" trip! Bob Fenner>

We think we now have a Mantis Shrimp. Should he live or die 8/28/05
Hi Bob, <James today>
We just put in a large amount of live rock and have heard a clicking sound.
We can see a shrimp. From pages on your site we think he looks a lot like a Mantis Shrimp. <Could be a pistol shrimp also.>
We have two Clowns (one a little bigger and one about the same size as the shrimp), a small anemone, A small bi-color blenny (about the same  
size as the shrimp), a carpet blenny, twice the size of the shrimp and some small brittle stars.
We did have some small crabs but I am likely the snapping sound was their death knell as I can no longer see them. <Sounds like a mantis>
Is there a high chance I will loose fish to this snapping hitchhiker?
<Possibly>
The fish, shrimp and rocks have been together for two days only so far... have I setup the makings for a sad end to my fish.
Would it be best to remove the mantis shrimp for all concerned?
<I would remove it.  They do sell mantis traps.>
I'd appreciate any thoughts you have on the issue.?
<James (Salty Dog)>
Regards
  - Matthew

- What to do with a Mantis Shrimp [is it safe?] -
<Greetings, Jason C here...>
Let me start by saying...mantis shrimp are tricky little boogers!  To recap, I purchased some uncured deco rock, and while curing it in a 20 gallon tank, I heard clicking/popping noises off and on.  The noises stopped, so I blamed my paranoia and imagination (and my husband says I'm in denial!).  Of course, now that the rock has been transplanted to my main tank, the noises have begun again and lo and behold, I have spotted the culprit.  The mantis shrimp is about 1 1/2" long and mostly hides in the rocks, but seems to be
getting bolder by the day, actually coming out into view when I shine a light in his hole.  My current tank inhabitants include: a maroon clown, a strawberry Pseudochromis, a Christmas wrasse, a three-striped damsel and critters include: Astrea snails, a few peppermint shrimp, a green brittle star, a pincushion urchin, a small red starfish and a pink and green cucumber.  I just want reassurance that I do indeed need to remove the mantis shrimp.  Any chance of the inhabitants continuing to live in harmony? <There is a chance, albeit a remote one, I wouldn't risk it myself. I'm sure you've read up on these, but I'll quickly reiterate - mantis shrimp [stomatopods] come in two basic varieties: smashers and spearers. These descriptions accurately portray their offensive capabilities. If your mantis is a spearer, your fish are most certainly in jeopardy as soft-bodied prey is the preferred food of the spearer. If your mantis is a smasher [the clicking certainly makes it seem like a smasher], then it would prefer crabs, snails - things it can bash into submission. That being said, all stomatopods are wily predators and will have no problem taking something not usually on their list. So... the choice is yours. There is also the chance that this is not actually a mantis shrimp but a clicking shrimp, also known as pistol shrimp. These shrimp make a lot of audible clicking sounds, and typically are much noisier than a mantis. If you haven't already, check out our pages on the subject:
http://www.wetwebmedia.com/marine/inverts/arthropoda/stomapods/mantisshrimp.htm >
I think I know the answer, but I don't want to believe it!  As always, thank you so much for the information, the website and the correspondence.  You guys are super-cool! <If I might add one more possibility for you... stomatopods make really fascinating pets, but would best suited to a tank all to themselves. A 10 or 20 gallon tank would suffice. Cheers, J -- >

More light for the tank?/possible mantis (03/12/03)
Hi everyone!
<Hi! Ananda here today...>
I have been working on my second reef tank for about ten months now. I have had very good luck with my soft coral tank (4 years) so I am now going to try a SPS tank. This one is 48X24X18(90G).  I built the hood with three sockets for A future addition of a 250W Iwasaki. The light hood has two 175W 10000K metal halide lamps plus two VHO actinics. I am trying to strike a balance between color AND growth. Would the 150W Iwasaki be enough or would
another 175W 10000K be more appropriate?
<Whoops... you mention a 250w first, then a 150w, then a 175w... each of these bulbs requires a different ballast. Do you have the ballast yet?>
The bleaching of the corallines is an issue with me, because I believe the corals will need the light. Should I add this light to the cycle now?
<No need to add the light when you don't have corals that need it...unless, of course, you read by tank light.>
I added the live rock back in September, and I probably won't begin stocking until May. I almost broke down and added a small school of green Chromis, but on one of my late night "safaris" I think I spotted A mantis shrimp possibly Gonodactylus platysoma (photo on blueboard.com) so I broke down the Q.T. (I will wait and watch).
<I would be setting up the QT to hold the mantis! They are cool critters. Even if you disagree, there are many people who would love to care for your mantis. Do check out the WetWebMedia site and WetWebMedia chat forums for discussions on how to catch and remove these critters, as well as how to keep them or where to sell them!>
The few snails and crabs seem fine.
<Keep a count on them...will help determine/confirm your species diagnosis.>
The water parameters are ammonia, nitrite, nitrate, and phosphate are not detectable. The salinity is 10.25, alkalinity 4.5 m/ltr., and calcium is 450. The water is changed every week at 6%.
<Sounds good.>
I would also like to thank Ananda and one other (maybe Anthony by the sounds of the humor maybe not) for your most recent responses.
<You're welcome... not Anthony, since he always signs off on his... sounds like one of the guys on the crew didn't want to get caught/blamed by your wife in case of your untimely demise!>
YES, I am the guy who spilled skimmate all over his living room carpet. The wife did not kill me (yet)! She just keeps asking me "When are you going to put fish in that d&%m thing?"
<Ah, the cry of spouses of hobbyists with new tanks everywhere... I would suggest you add a couple of clownfish-shaped food clips and point to them next time she asks.>
Thank very so much again Ben.  
<You're welcome. --Ananda>

Killing a mantis with cold...
hello
I've heard that mantis shrimp can't take the cold.  I
was wondering if I let my tank cool down to the 60s or
lower for a few hours, would that likely kill the
shrimp?  all I have so far is live rock.  if you think
this might work, how low should I let the water cool
and for how long?  except for the Aiptasia (another
problem to solve) I wouldn't want the life on the LR
to die.  it's mostly sponges, feather dusters,
Christmas tree worms, turkey wings, and other such
things.
thanks,
warren
<Mmm, I wouldn't go the chilling route. You're very likely to kill more of the desirable "live" part of your rock than the mantis. I would instead try baiting, trapping it/them out. Please read here re:
http://www.wetwebmedia.com/marine/inverts/arthropoda/stomapods/mantisshrimp.htm
and the linked FAQs (in blue, above). Bob Fenner>

Re: killing a mantis with cold...
thanks, bob, for your quick and helpful reply on my
mantis shrimp problem.
<Welcome>
tried the x-terminator over a period of 4 nights using
raw salmon (fresh each night) and then a meaty frozen
fish food, all with no success (or even a nibble!).   
<Yum, am coming over to your place... don't give up here... may not be hungry enough, or like other types of food. Try a bit of shellfish (like a cocktail shrimp piece or oyster...)>
decided to go the tedious club soda route.  first
tried pouring club soda over each piece and into the
holes, but was unsuccessful.  so bought a ton more
club soda and dunked each piece of LR for about 3
seconds each.  that worked like a charm.  got both
inch-long shrimp.   
<Oh! Congrats>
moreover, after 2 days, it doesn't appear the process
has hurt the LR at all.   
<Good to hear/read.>
thanks again,
warren
<Thank you for the follow-up/input. Bob Fenner>

Mantis shrimp (02/20/03)
How do get the darn thing out
<Many suggestions in the mantis shrimp FAQs, linked here: http://www.wetwebmedia.com/marine/inverts/arthropoda/stomapods/mantisshrimp.htm ...more suggestions on the WetWebFotos chat forum (http://wetwebfotos.com/talk/. --Ananda>

Mantis killer
>Hello.  
>>Hello.
>Need your help.  I've recently introduced gulf live rock to my 120gal tank to start my cycle.  
>>I shall assume that this rock has been cured.
>I noticed a few nights ago that there's some clicking coming from the tank.  I have a strong feeling this is a mantis shrimp.
>>I would tend to agree.  Not a good feeling!
>Although I haven't seen it yet, I'd live to dispose of it before I put my clean-up crew in there in 3 weeks.   My question to you is, once my cycle is complete, is there any fish or eel that would make a nice treat out of the mantis.
>>None that I know of that would be reliable, though I've read several recent reports of Coris gaimard that have been seen eating mantis shrimps.  In one instance, the C. gaimard was a juvenile.  These are a hardy, fairly peaceable fish to have, not to mention their spectacular juvenile and adult coloration.  I have found them to be very easy keepers.
>I would like to avoid going the trap route since I hear that most of them don't work very well.  Please help.  Demetrius
>>Yes, the mantis is a very clever shrimp, he is.  What I would do first is begin a process of separating the pieces of rock, in order to narrow down where the mantis may be.  This will take time, space, and energy, but after having one entire reef tank of my own wiped out of all motile inverts/non-cnidarians it's worth it to me.  Be careful, though, these shrimps are known in some locales as "Thumb splitter".  Good luck!  Marina

Will mantis shrimps or bristle worms in any way damage corals or clams? 6/15/03
<Hello, PF with you tonight>
Will mantis shrimps or bristle worms in any way damage corals or clams?
<Ok, I'll break this down:
Mantis shrimp will generally not harm corals, unless they disturb them by walking across them. Depending on the relative size of the clam and the mantis, and the type of mantis (smasher vs. spearer), it could kill and eat a clam. A 2" mantis is no threat to a 10" clam, a 6" mantis is another story.
Bristle worms: in general, no. If they are in plague numbers, they could irritate a corals tissue. As for clams, they have a bad, and undeserved rep. Often a clam with be doing poorly, but still look healthy overall. The clam dies overnight and the worms come out and eat it, the nest morning the aquarist sees the worm shell crawling with worms and makes the obvious (but wrong) conclusion. There are a few species of worms that prey on clams, but they are very rare in captivity.
Bear in mind these are generalizations, you can get a more specific answer with a more specific question. So on that note, have a good evening, PF>

Fight of the Year!  Coral Banded Shrimp vs. Mantis!
>Saludos Salados:
>>Greetings!
>Last week I purchased a CBS and placed him on a 10gal tank. This tank has been running for a year with no apparent problem. The other tankmates are a Cinnamon Clown a Turbo snail and a couple of Bumble Bee snails.
>>Alright.  And now..??
>Recently my wife noticed a strange animal in one of the life rock holes. For her description I think we have a Mantis in the tank.
>>Oh no.. <groan>.  I had a tank wiped out by a mantis once.
>This would explain the disappearance of a Royal Gramma about a month ago.
>>It would explain it quite neatly.
>My question is, will the CBS kill the Mantis or the other way around?
>>My money's on the mantis, hands DOWN.  As a matter of fact, being as how I'm NOT a gambling woman, I would actually put money on that one.
>I am concerned for the CBS (named Jacques) which my son regards as a cool pet to have.  Best Regards; José A. González
>>I would be concerned as well.  There are those who've had luck using different traps.  At the very least (and often the best), if you can determine which piece of rock it's in, then you can remove it to a pail of fresh water.  This will cause the animal to exit IMMEDIATELY, and allow you to put the rock back in sans mantis.  Marina

Bloody Shrimp 12/10/03
Hi;
<Hi Antonio.  Adam here today.>
I have a 3 foot tank, and I have had a mantis shrimp in there. One night despite getting rid of three and a larger one on one occasion, I still have more clicking in the tank. What can I do?
<First of all, don't panic!  Even if it is another Mantis, most that are incidentally collected with rock are smashers (spearers tend to inhabit soft bottom habitat).  While dangerous to small invertebrates, smashers are very unlikely to harm fish.  I would continue to apply whatever trapping method that was successful for you in the past.  Also keep in mind that harmless pistol shrimp could be producing the clicking.
I have heard about dipping rocks in soda water but this can be very detrimental. What is the best way to get rid of them if you cant find them?
<For the soda water trick to work, you obviously have to know which rock they are in and be able to remove it.  I would try trapping first and consider the soda water trick as a last resort.  I would also suggest targeted pouring of the soda water over a total dip.  Please do avoid clearly harmful tactics like prolonged freshwater exposure and boiling water. HTH! Adam>

Who Will Win the Shrimp War. I'll bet on the Mantis (12/10/03)
Saludos Salados: <Greetings>
Last week I purchased a CBS and placed him on a 10gal tank. This tank has been running for a year with no apparent problem. The other tankmates are a Cinnamon Clown a Turbo snail and a couple of Bumble Bee snails.
Recently my wife noticed  a strange animal in one of the life rock holes. For her description I think we have a Mantis in the tank. <Uh oh> This would explain the disappearance of a Royal Gramma about a month ago. <Quite possible.>
My question is, will the CBS kill the Mantis or the other way around? <I'd put my money on the Mantis any day. It has a much more formidable weapon>
I am concerned for the CBS (named Jacques) which my son regards as a cool pet to have. <CBS are way cool. I love mine. Do get rid of that mantis. Start here: http://www.wetwebmedia.com/marine/inverts/arthropoda/stomatopods/mantisfaqs.htm>
Best Regards; José A. González

Mantis shrimp 11/3/03
Hello to all, I have a question concerning a mantis shrimp (little brown type about 2"), I have tried various traps but it is smart and all attempts have failed.
<Hmmm... there is likely no need to remove it anyway. Pause and get a correct species ID (look on the net at the Stomatopod reference sites). Yours is quite likely a smasher (not a spearer) with an adult size of just a few centimeters. If so... it is harmless>
I have not noticed any deaths so I am assuming that the mantis is getting enough to eat without killing my fish, shrimp or snails. Is it possible that it is feeding on copepods?
<microcrustaceans yes... but copepods are rather small. Amphipods more likely. Other larger infauna from the sand too>
Since trapping has failed I have decided to let him be, so my question is what can I put in to feed him and keep him content,
<most any small bits of thawed frozen meaty foods placed near its den/lair>
I was thinking about some blue leg hermits since they are cheap.
<good heavens! unnecessary and a poor use of a living resource. No need, mate... wholesale meats of marine origin are fine - fish food. Best regards, Anthony>

Missing in Action - Must Find That Mantis! 
>Hello to all, I find myself scratching my chin yet again and staring at my tank like the RCA dog, a daily occurrence. I have/had a yellow tail Coris wrasse ~ 5-6" ~ for over a year and he made the move from my 55 to my 125 four months ago without any problem.  In addition I put a three inch two line goby in the display tank last Sunday and haven't seen him since.  I've heard the loathsome intermittent clicking noise coming from the tank since day one and have yet to see the devil.
>>Uh oh.  I know this story all too well.
>I tried to flush it out when transferring the live rock by exposing all the rock to a bath of hyposalinity for three to four minutes per my LFS guidance counselor.
>>Fresh water dipping is generally most effective, but it helps to have an idea of which rock/rock group to go after.
>My question is it likely that the shrimp could/would catch and devour either or both fish in a two to three days time?
>>Hhmm.. depending on the size of the mantis, I'd have to say it's a good probability.  Especially if it found the wrasse, though large, buried and at night.  I'm assuming your tank is well-covered and you've done the search all about, even in the places where "it's IMPOSSIBLE they'd land there!".
>I have check all around the tank, floors, overflows, hood, probed the sand bed, checked the tank with lights off,  looked behind the tank with a mirror.  Ammonia isn't up and I don't know if it's worth breaking down the tank and disturbing the other fish and more than I have to find them or what left of them, ughhh.  :(  Any thoughts or suggestions, and again, thank you ahead of time.  Steve Suniga
>>In a tank that size, even if the fish just kicked with no help from the shrimp it doesn't necessarily follow that the ammonia would spike.  However, as I said, it could be likely that they've been nailed if you're rather certain (the clicking sure is a bugger) you've got a mantis.  In this case, I think it is QUITE worth it to do what you can to find that shrimp.  They can, do, will, and HAVE decimated entire tanks.  I even lost a gorgeous Tridacna derasa to a mantis (just smashed it open, even when it was said it would never happen, it did).  Must find that shrimp!  Marina

Mantis In The Mist (Mantis Shrimp...)
Hello to all,
<Hey there! Scott F. with you today!>
I find myself scratching my chin yet again and staring at my tank like the RCA dog, a daily occurrence.
<Well, as long as you are not scratching other body parts while staring at the tank, then you're on the right track here...>
I have/had a Yellow Tail Coris Wrasse  ~5-6" for over a year and he made the move from my 55 to my 125 four months ago without any problem. In addition I put a three inch Two Line Goby in the display tank last Sunday and haven't seen him since. I've heard the loathsome intermittent clicking noise coming from the tank since day one and have yet to see the devil. I tried to flush it out when transferring the live rock by exposing all the rock to a bath of hypo salinity for three to four minutes per my LFS guidance counselor.
<You could also try one of the "traps" designed just for that purpose...>
My question is it likely that the shrimp could/would catch and devour either or both fish in a two to three days time?
<It is certainly possible...And it is equally possible that you may have more than one...>
I have check all around the tank, floors, overflows, hood, probed the sand bed, checked the tank with lights off,  looked behind the tank with a mirror. Ammonia isn't up and I don't know if its worth breaking down the tank and disturbing the other fish and more then I have to find them or what left of them, ughhh.:( . Any thoughts or suggestions, and again, thank you ahead of time. Steve Suniga
<Well, Steve- short of removing all of the suspected "hideouts" of the Mantis Shrimp and suspending the rock in a bare tank, or dipping the rock in carbonated water, you may need to resort to one of the aforementioned "traps" in an attempt to catch this guy (or guys...). Keep up the high level of alert, and maybe you'll nab the little scourge...Good luck! Regards, Scott F>

Mantis menace
Dear Mr. Fenner,
<Devon>
My husband and I have recently become marine aquarium enthusiasts.  We purchased a 28 gallon tank and have around 35 pounds of LR in it.  We set it up a little over two weeks ago with 100% live sand.  We have 2 medium damsels (for cycling purposes), a hermit, an arrow crab, 2 turbo snails, 2 urchins (stow-aways on the LR), a peppermint shrimp, and an anemone that grew on it's own from the rock.  From everything that I have read and heard, we apparently have at least two mantis shrimp living in our rocks.  We have seen the larger of the two (about 2 1/2-3 inches in length) go after our peppermint shrimp.  From reading on your site and from things that I have heard, it appears that these are rascally little creatures that are very hard to deal with.  The larger of the MS lives in one of our foundation rocks.  Can you tell me the method that YOU would try first to get these little buggers out before the hurt something (especially our arrow crab)?  Thank you for any and all advice you may be able to give me.
Devon Vickers
<If you can definitely see where they are, in this small size system I would gingerly (for fear of bodily damage) remove the specific rocks and flush them out with soda water (yes, carbonated drinking water)... if this doesn't do the trick (next trial) I would try baiting them out with a tasty shrimp (cocktail sans sauce) and fishing line toward evening... with a speedy, sure hand net! Lastly, if these two techniques don't remedy the condition, I would go the plastic (Home Depot, Lowe's) mouse trap route with a meaty bait. Get 'em outta there! Bob Fenner>

Mantis menace II
Thank you so much for your help regarding the nasty little mantis guys.  We got the two that we know of out last night.  Oddly enough, one of them came over and jumped onto the side of the net and climbed right in!
<Hee hee, some Darwin Award candidate in the crustacean class now!>
The other one was a very tricky matter.  We had bait in there, but he was just not going for it.  Finally, my husband got mad and took the whole rock out.  He but it in a bucket and the thing would not come out.  We didn't have any carbonated water, so my husband had to go to plan b, which was to skewer the little sucker, which, he successfully did.
<En garde!>
  Those little guys are vicious!  Anyway, who knows if there are twenty more lurking around in there, but we got the two big guys out.  The smaller was about 2 inches and the bigger one was a good 3 to 3 1/2.  YUCK!  Have a great day!
<Beautiful animals, but destructive in the "wrong" settings. Cheers, Bob Fenner>

How dangerous is a Mantis shrimp?
Hello all, << Hi, Blundell here. >> I have identified a Mantis Shrimp it is a Gonodactylus (little
green 2.5"). I have tried trapping  without success, very smart fella. My
question is what threat/damage could this little fella do. << Overall not much damage.  He isn't going to terrorize the tank and eat everything.  What he can do is eat a few small fishes and pick on some other small invertebrates. >> I am starting to
like him but if he is going to reek havoc of my hermits and snails (maybe
clam) << He may eat some, but people who keep Mantis shrimp often have hermits and snails in those tanks anyway. >> then I will continue on trying to remove. I read in one of the  FAQ
where this species was referred to as harmless, I thought harmless and
Mantis were two words never associated with each other. << Well harmless to your corals.  Maybe not so harmless to little fishes, but then again what is? >>
Thanks again for your time.
<< To remove him, I recommend scaring him with a stick so he hides in a rock... then remove the rock.  If you keep him, I would suggest feeding him every few days in hopes of preventing him from being too aggressive. >>
Mike Winston
<<  Blundell  >>

Help with an Eviction
Please help:
<I'll try! Ryan with you today>
I have a buddy with an 80 gallon bow front. He has had it up for 6-8
months and was loaded with emerald crabs and fire shrimp. They have all
disappeared in the last 2 weeks. Last night he saw a tail flapping
around after the lights went out. Mantis Shrimp maybe! <Prime suspect> If so how in the
world do you catch the little bastard? <Glass trick: Take a pint glass, lean it upright against the rockwork.  Leave a few silversides or meaty item at the bottom, and he'll jump in to get them.  He won't be able to climb back out, but he'll be good and mad so watch your fingers.  If not a Mantis Shrimp, any
ideas? <The tail is a good clue that it's a mantis.  You may even want to set up a small aquarium for this creature- It's quite fascinating.> Everything else seems to be fine. Snails are still there and fish
seem fine.
<Won't be long unless he finds the shrimp! See ya, Ryan>
Brian

Rogue Stomatopod?
My girlfriend has a 20g reef tank and she's been having a problem with disappearing fish.  She had a small ocellaris clownfish since she first started the tank about four or five months ago.  A couple of weeks ago he mysteriously vanished over night.  A month or so before she put in a firefish, which vanished within the first couple of days.  Three days ago she put in a pink skunk clown, and this morning he was gone.  None of these fish have shown any signs of stress or poor health.  She's got zebra leg hermit crabs, snails, a Ricordea, glove polyps, a couple of feather dusters, and an abundance of copepods that visibly multiply in the tank, and a clown goby who's been in there for about two weeks, and a more recently added electric eye scallop.  The goby is looking lonely, and Jenny's getting really discouraged, and thinking she should give up on fish all together.  Water conditions are primo, no amm, no nitrite, 20 ppm nitrate, 1.025 sg, pH 8.3...every invert she has every put in there has thrived.  We've never observed any predatory crustaceans, but I don't know what else it could be.  She's got 30lbs of live rock so there's plenty of hiding spaces.  As far as traps go are there any superior models or brands?  Is there anything else that would cause fish to disappear entirely?
***Hey Scott,
Assuming these fish are not jumping out (something fire fish are notorious for) then it very well could be a mantis shrimp. Try examining the tank a hour after lights out with a flashlight - sometimes this turns up the culprit. One thing you could try is a hyper saline dip. Remove the rocks and soak them (do not soak any corals) in a bucket with salt water mixed to 1.036. This should cause any mantis that's hiding in the rock to exit almost immediately. Leave the rocks in this solution for no more than two minutes, as the hyper saline conditions could cause unwanted dye off on the rocks.
The other option is a trap, and I believe there's one specifically designed for stomatopods. Do a search for "mantis trap" on the web and you should find it in short order if that's the case.
If you do find a mantis, you might want to consider setting him up in his own small tank. They are very intelligent, and make fascinating pets.
Good luck!
Jim***  

Rogue Stomatopod, Part Deux...
Hello Tracy,
For any Gonodactylus, or other "smasher" variety Stomatopod, an arrow crab is nothing but a meal. I'm not sure what the logic behind putting an arrow crab in the tank was.
I would try a trap first. If that fails, you can try a hypo saline dip. Mix the water to 1.036 and dip the suspected rock (if you can best guess which rock he's in). Leave the rock in this solution for two minutes, no more. If he's in that particular rock, this should send him scurrying out.
Good luck
Jim***
We recently discovered that we have a mantis shrimp living in our live rocks, her has been coming out every couple of days so we can see him, but he's too fast for us to catch him.  We don't want him in there because of the harm he can do to the tank, so we inquired with our local fish store what to do.  They suggested buying a trap, which they stated had about a 50/50 chance of catching him, or adding an arrow crab to the tank to seek him out and kill him.  We opted for adding two arrow crabs to our 65 gallon tank, they have been there for about 24 hours now, one has already molted.  What do you think about this strategy?  Can you think of anything else?  We had thought of taking out the rocks and running them through fresh water, but we don't really want to kill other stuff living in the rocks, plus we are not 100% sure which rock he is living in (he moves around).  We have several corals, live rocks and a few fish (left!).  Thanks,
Tracy  

Rogue Stomatopod, Part Tres!
We have tried the trap for about 3 days now, the only thing it is doing is
feeding the arrow crabs.  They are scurrying off with the bait every night
and having a feast.  They don't weigh enough to set off the trap even though
we have it set at the most sensitive setting.  Dumb question...how do I get
the water for the dip to 1.036?  I think we might want to try that next.  Do
you think that a fresh water dip is not advisable?  Also, if he doesn't
scurry out of the rock, how do we know if he is dead before we return the
rock to the tank?  We tried the fresh water dip over the weekend on a piece
of branch rock that my husband was sure he saw the mantis go in to.  He
wanted to verify that the mantis was dead and took a hammer to the rock.
Guess what, he wasn't in there!  No more smashing rocks!
Thanks for your help.
Tracy
***You need to add salt mix to the dip water until it reads 1.036. This will be easier on the rock than a freshwater dip. Still, do it no longer than two minutes or so. If he's in the rock, he should come out. However, nothing is for sure and I've seen mantis shrimp drive reefers off the deep end. :) This could very well be "JUST THE BEGINNING" MUAAAHAHAHAHAHA!
Hope not, and I wish you luck. I would keep the trap, and lose the arrow crabs for now.
Jim***

Catching a mantis
We recently discovered that we have a mantis shrimp living in our live rocks, her has been coming out every couple of days so we can see him, but he's too fast for us to catch him. << Seen this happen many times. >>  We don't want him in there because of the harm he can do to the tank, so we inquired with our local fish store what to do.  They suggested buying a trap, which they stated had about a 50/50 chance of catching him, or adding an arrow crab to the tank to seek him out and kill him. << I don't think that will work. >> We opted for adding two arrow crabs to our 65 gallon tank, they have been there for about 24 hours now, one has already molted.  What do you think about this strategy? << I think the mantis is much more dangerous and could kill an arrow crab any time it wants to. >> Can you think of anything else? << Yep, rock removal.  Lots of people just lift the rock out, put it in a bucket and shake it around until he falls out.  Works surprisingly well. >> We had thought of taking out the rocks and running them through fresh water, but we don't really want to kill other stuff living in the rocks, plus we are not 100% sure which rock he is living in (he moves around). << That can be a problem. >>  We have several corals, live rocks and a few fish (left!). << I know other people who have little traps.  They just lend them out free and share them.  Also, they are way easy to make out of acrylic.  So the trap idea isn't a bad idea because you have nothing to lose. >>  Thanks,
Tracy  
<<  Blundell  >>

Catching a mantis
Hello.  Yes, I've been to utahreefs.com and they have some good info
too.  Well, I caught my mantis this weekend using the 5 second dip
method.  He's now in a 3 gallon eclipse all by himself, and not too
happy, I'm sure.  << Can I come see him?>> I need to put some rock in there for him/her/it.
Problem is, after I had everything re-assembled in the JBJ, I heard
another click . . . maybe I was just hearing things.  Anyhow, the mantis
is about 1 inch long total and not all that colorful.  Mostly grey and
maybe a little bit of pink here and there.  It hasn't busted a hole in
the acrylic (yet), for that I am thankful.  I am considering keeping it
permanently.  Its kinda cute.  You are welcome to come take a look at it
and take photos. << Great, I'll give you a call. >>  Where it is now in the 3 gallon with no ornaments
should be easy to get a good shot.  Just let me know.
Tom
<< Thanks, Blundell  >>
 

Compatibility - Update on Their Night Stalker.. Calling Richard Ramirez!
To Salty Dog James (God I love that call name!).
<I've had it for quite some time, don't steal it:)> 
Update on our night stalker. We really like this little guy, so we would hate to part with him but sure we have figured out how he launched his operation. Our tank lights go out before our china hutch (all on timers). When the tank lights go out, the crabs leap into action. However, the hutch lights throw just enough light to create a 'moonlight' effect in the tank, so we are sure this is how our Pixie discovered them moving about, thus started his hunting activities. We now have the hutch and tank lights on the same cut off time hoping that will eliminate the problem.  I tried to research it, and can't find anything indicating Pixie Hawks being night hunters. 
<If they can see, they can hunt. Some fish have excellent night vision. Right now you are playing Russian Roulette. Maybe consider a tank of his own. Getting back to the call name.  I have been in the hobby since 1969. The last six years developing a whitish beard, so my cousin's husband started calling me Salty Dog knowing my love for the salt water hobby. James (Salty Dog)>