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>>

Descriptions Match... Hope I'm Wrong/Hitchhiker ID 8/26/09 Greetings to the Crew, Richard here: <Hello Richard> As always your site and team are a valued resource, and I thank you for the prompt reply to my previous request for information. <You're welcome.> I found an observer in my tank, seems to have been watching me for a while. (Hope I got the pics in focus and formatted correctly.) <Is fine.> The 'eyes' seem to alternate from each other (one open whilst the other isn't). Doesn't seem to concerned with light as this was taken under full light, but doesn't venture further then you see. Oh yeah, in the fear that the term 'predatory' was part of it's vocabulary I tossed it a piece of sea bass... took it faster then my Grandmother could yell bingo! Ok, I've braced myself... could this be a variety of Mantis Shrimp? <From what I can see of it, it sure looks like a specie of Mantis Shrimp.> I appreciate your time and efforts, Thank you. <You're welcome. James (Salty Dog)> Richard J.C.

Pistol or mantis hitchhikers: Hard to tell, but best guess is a pistol.. Hitchhiker\Pistol Shrimp\Mantis Shrimp 8/23/2009
Hi team,
<Hi Kevin.>
I'm finally restarting a SW tank after the first one was destroyed by hurricane Ike. Four weeks without power is apparently bad for SW tanks... sigh.
My new tank has been setup for 6 weeks or so. It's a 44g pentagonal with a 96W PC fixture, an Aquaclear 70 HOB filter (sponge and ceramic bio pieces only), a Koralia 1 and a Maxi 900 with a sponge filter on it. I started cycling it 3 weeks ago and had 40 pounds of dead rock. I added about 10 pounds of 'fully cured' liverock and about 30 pounds of live sand. Tank was cycled in two weeks. Last weekend I added a torch coral and a small rock covered in green star polyps. I got a pair of mushrooms as hitchhikers on another rock and some clove polyps on yet another rock.
<Everything sounds good so far.>
So that was 3 weeks ago. Yesterday, my wife mentions that she's hearing clicking sounds from the tank. Finally tonight, I heard them too. They are pretty loud, but seem to be single pops. However, the rock that's in the back of the tank seems to have a lot of 'debris' around it... like silt or something. It could be just that, that the flow of water has cleaned the rock of debris (and I have it in a different position that the tank I got it from).
<Possible Mantis and Pistol shrimp are diggers too.>
The tank I got this live rock from is a LFS's cured live rock tank.
There is nothing in that tank but live rock.
<As far as anyone knows.....>
I have dealt with the misery of mantis hunting before and did not enjoy it. I guess the question is would a mantis or pistol shrimp, not do anything for almost 3 weeks and then start popping?
<Very possible.>
I know they are crustaceans, but can they go 3 weeks without food. There is no mobile life in the tank except for some tiny worms and some very, very tiny blue starfish.
<That is what is making me lean towards a Pistol Shrimp. You can put a few crabs in the tank as a test. If it is a mantis, it will come out after the crabs.>
I was thinking of adding a pair of clowns this weekend, but I don't want to if I have to go mantis hunting.
<Put a few crabs in the tank and see what happens. To look at it another way, Mantis Shrimps by themselves do make for an interesting display.>
It's just weird that nothing happened for almost 3 weeks, then pops.
Thanks for any info you have.
Kevin
<MikeV>

Deep Water Crustacean Caught: Likely a Mantis Shrimp, yes, you can eat them 4/28/2009
Hi,
<Hi Bill>
While grouper fishing yesterday in about 70 feet of water in the Gulf of Mexico 20 miles off Venice, Florida, I caught an unknown crustacean.
<OK>
It was about 12 inches long, and had exoskeleton like the tail of a lobster, yet almost clear, and uniform width of about 2.5 inches from front to back.
It had two arms in the front, long and doubled back like a praying mantis arms. These "arms" were holding onto my squirrel fish cut bait. At the back it had two or more sets of scissor pincers.
<Heheh. Lucky it was interested in your bait and didn't try to sample your hand.>
Do you know what this was?
<Likely a Mantis Shrimp Look here and see if anything looks familiar.
http://www.wetwebmedia.com/marine/inverts/arthropoda/stomatopods/mantisshrimp.htm >
Is it rare?
<Not in the slightest - I'm betting most that keep marine tanks with they were much rarer than what they are.>
Is it eatable?
<Actually, they are - do a Google search on the web - there are several recipes for them.>
Thanks for your help.
<My pleasure>
Bill
<Mike>

ID help please, Mantis 4/11/09 I have been searching for an identification on this guy for quite a while and was hoping you could help. <Will try.> I first noticed him in my tank ~ 6 months ago and have done some searching for an ID from time to time since I haven't been too worried about him. In the last two months I have lost 2 bottom dwelling fish and am a little concerned that he may be the culprit. <A possibility.> He is yellowish green in color and is about 2 inches long and his tail looks somewhat like a shrimp. <Not a true shrimp, but commonly referred to as a Mantis Shrimp, of the order Stomatopoda. Judging by the picture could very well be a "spearer" as opposed to a "smasher" and a threat to fish. Nice looking specimen here.> My only guess is that he is some kind of isopod. He is very illusive and while not very good the attached pictures are the best I have been able to get since I noticed him. <They are quite secretive and clever.> He is kind of neat and I am hoping that he is not too destructive as my 2 year old daughter is very fond of her "Creepy Eyes" Thank You -Josh <I would remove this, could be a threat to your other livestock. There are several commercial traps that are fairly effective in catching these clever animals. However they are quite attractive and popular to keep in their own dedicated tanks. Perhaps a small tank just for him would be an option here for your daughter, just make sure little fingers are kept outside the tank, these crustaceans are often refer to as "thumb splitters" for a reason. For more check out here http://www.wetwebmedia.com/marine/inverts/arthropoda/stomatopods/mantisshrimp.htm and the links in the bibliography.> <Chris>

Mantis Shrimp ID: Likely Family: Gonodactylidae – 2/4/09 Hey all, <Hi Scott, Lynn here this evening.> Although you've heard it many times before, you guys are fantastic! <On behalf of Bob and my fellow crewmembers, thank you very much!> I have read and learned tons since deciding on starting into the marine hobby over a year ago. Last April I started a 150 gallon FOWLR. <Very nice.> I got quite a bit of live rock off a guy from EBay who was unloading a ton of great looking stuff - full of life! I’m still seeing new things. It took me about 6 months to realize there was a (only seen one) Mantis Shrimp in residence. <Yep, there's probably just the one. They’re decidedly un-neighborly when it comes to fellow Mantis Shrimps.> I just moved recently and with the new set up, he has settled into one place and I see him peeking out his hole often. <Neat> My question is if anyone can identify this guy (know there are hundreds of species). <Indeed! Well, I may not be able to offer a species name, but thanks to your terrific photos, I believe I can at least narrow things down a bit. What you have is a pretty little Mantis, most likely in the family Gonodactylidae. It’s also highly likely that it’s a “smashing” variety rather than a “spearing” one. I’m leaning towards Gonodactylidae because the basic shapes of the visible body parts and eyes are right and it’s got the typical spine on the rostral plate (just above/behind the eyes). The deciding factor will be the shape of the various parts that make up the tail section. Since we can’t see that area in the photos, I’ll supply a link for you that illustrates it in detail. It also has more information on the family itself: http://www.crustacea.net/crustace/stomatopoda/www/gonodac.htm You may find the following two links helpful when it comes to the various terms used at the listing above: http://www.ucmp.berkeley.edu/arthropoda/crustacea/malacostraca/eumalacostraca/royslist/notes.html http://bb.wetwebmedia.com/gallery/pic.php?mode=large&pic_id=269 For more information and photo comparisons, please see these links: http://www.wetwebmedia.com/marine/inverts/arthropoda/stomatopods/mantisshrimp.htm http://www.ucmp.berkeley.edu/arthropoda/crustacea/malacostraca/eumalacostraca/royslist/ http://www.blueboard.com/mantis/ > I think he's fascinating, <I couldn’t agree more. They’re wonderful little creatures that have the most amazing eyesight imaginable.> …but need to know how big he should get, etc so I know if I need to try to remove him now. <That’s understandable. All I can tell you though, without knowing the species is that since your Mantis is most likely a “smasher”, it poses more threat to snails, hermits and the like, than to fish (the main prey of spearing Mantis). That’s not to say that fish are completely safe (especially slow movers), they’re just at less risk. Keeping the Mantis well fed will go a long way to avoiding any problems there. One thing to consider, that you’ve probably already heard/read about, relates to the potential for Mantis Shrimp to break aquarium glass. This is something that obviously depends on the size of the Mantis as well as the thickness of the glass. I would read through the information at the various links above and decide for yourself whether this might be an issue down the road. I can’t imagine that at less than 1”, your Mantis could do significant damage to the thick walls of a 150g. If I were in your shoes and didn’t plan on adding any snails, hermits, crabs, etc, I’d keep that little Mantis well fed and enjoy him! I’d just watch and only remove if/when he gets too big or poses a threat to your livestock/tank.> He's probably less than an inch long right now. <Awww, he’s just a little bitty thing, isn’t he!> Thanks for the info. Hope the pic’s make it across. <Yes, thank you. They made it just fine.> Scott <Take care, Lynn>

Mantis  11/12/06
Hi WetWeb crew
<Shellman!>  
  I have this mantis shrimp in my tank. I very rarely see him, but today I got a good look and saw that he is about 3 inches long.
<Beauties eh?>
I read through your articles on these and now I believe that this one is a smasher. The reason is because I have lost 3 hermit crabs and several snails. I had no idea what was killing these inverts. Then one day I saw my coral banded shrimp eating a big chunk of snail and guessed it was him killing them.
<Might be the Stenopid also, alone...>
The dead snails have had the tops of their shells broken off and the insides devoured.
<Oh... this is the Stomatopod>
Well the thing is, I have also lost several small fish inexplicably. Is it possible that a smasher mantis would also eat fish?
<Oh yes...>
All fish that I lost were either very small or had just been placed in the tank and were hiding in the live rock. I have 2 small clowns and a small Hawkfish which have thrived in this tank-and I suppose, have been very lucky now that I have seen what is hiding in the rocks. Do you think this mantis will try to catch my fish?
<Yes... Best to either remove it out of harms way to your other livestock... or try feeding it to otherwise lessen the temptation. Bob Fenner>

Mantis on the loose  - 5/5/2006
Hello Crew,
<Jason>
I do believe that I have a Mantis (or multiple Mantis) problem.  I started up my 30 gallon tank 8 months ago. Did everything "by the book" with the cycling of the tank/live rock checking my water parameters and using the correct lighting. ( I am using RO water)  I started off the tank by adding three Blue/Green Chromis after the tank had cycled.  Within three days all three had vanished.  So I thought that I probably should start off with a couple of Blue Leg Hermit crabs and a couple of Turbo snails.  That worked
fine and after about three weeks of them being in there I decided to do it again with the Chromises.  Once again one after another they vanished.  So
I stopped buying them and picked up a few more Hermit crabs (thinking that I just have no ability to keep fish in the tank).  After a while I started
to notice that I was gaining more empty shells than I had hermit crabs. So I went out and bought more empty larger shells thinking that the reason
they were dieing was because they were out growing their shells and were falling victim to one another in fights over the larger shells.  Next I
developed an Aiptasia problem and reading over your sight and suggestions (thanks by the way!) I went out and bought a Peppermint Shrimp.  Well I
took it home and waited an hour and half filling the bag with my own tank water and allowed it to get to the right tank parameters and allowed to
get used to my tank conditions.  I netted it and released it into the tank.  The Peppermint Shrimp was doing great and all that good stuff but
the next morning it was no where to be found.  So I waited yet again for another two weeks, tested the water (no problems) every other day and
bought two clown fish who each started to swim vertically after day 3(one gone) and day 5(second one gone). ( almost made it a week!)  So I waited
until two weeks ago and bought three more Chromises and two Peppermint shrimp (on a Saturday).  The next morning both the Peppermint shrimp were
gone (Sunday). Monday a Chromis vanished and the same for Tuesday.  So right now with all the filler spacing in-between time I have 1 Chromis, 7
Turbo snails, and 8 Blue Legged Hermit crabs left.  If I really do have one or more in my tank I am just tired of feeding them everything that I
put into the tank.   I have tried a store bought trap that has not worked and also a pint glass with a fresh piece of shrimp in it and it has not
worked yet.  Any other advice you have would be really appreciated in trying to catch these guys.
Thanks for your help!
Jason
P.S. I have not heard any type of snapping coming from the tank.
<This does read like a Mantis problem... best to systematically take each piece of live rock out and dip it in freshwater... with or w/o soda water added... this should flush out the culprit/s here. Bob Fenner>

Pistol or Mantis? and adding fish   12/28/05
Hi Crew!   Hope you all had a great holiday. So since the 6 months from my first e-mail to you, things have gone very well.  Tank is very stable, and
my skeptical wife now loves it.  We spend at least an hour every evening after we put our daughter down for the night just watching the tank and talking.
<Ahhh!>
She has named all the fish and has identified personalities in all of them.  Even the dog gets into the act.  (Dog barks when my smaller
ocellaris "surfs" the current from my Sea-swirl from 1 side of the tank to the other, which at night it will do 15-20 times in the last hour before the
light goes out!)  She has protested any time I talk about moving rock around.  So my point of all of the above is that the tank is really in a
great place and I don't want to do any major overhauls.
<Okay>
Tank basics:  72 Bow Front, 100lbs LR, 20g refugium with 8" DSB, 40g sump, 3/4 sand in display, 2x175w 10K MH on for 9 hours a day, 2x96W PC 420nm
Actinic on for 12 hours a day.  2 Ocellaris Clown (2" and 1 3/4").  Foxface Rabbit (4"), Hippo Tang (2 1/4"), Starry Blenny (4 1/2"), 2 cleaner shrimp
(3 1/2" each), 2 peppermint shrimp (1 1/2" - new adds) 2 Mithrax crabs.  Oh and 24 Astrea snails, 4 Mexican turbo, 10 Nassarius.
So for the last 4 months I have heard a popping from the tank.  I tried trapping, but I kept catching the Mithrax crabs (damn them).  I hear two
types of popping.  1 loud popping that occurs sometimes at full light and definately under just the PC and dark.  The pops only come in 1s and
sometimes in 2s, but I would characterize as loud.  Usually several minutes between pops.   The 2nd type of popping is more of a quiet clicking.  Happens
just after light goes out.  Happens in multiples, but not rapid fire, usually 15 to 30 second spacing.   
So my question is Pistol shrimp, mantis, or maybe both?
<Likely Pistol/s... from the loudness, frequency, absence of dead crustaceans (the Mithraculus would be gone)>
What exactly should i be looking for?
<Small alpheid/s... they hide, especially during light hours>
I have not seen either of them and I have spent many the hour with a flashlight scanning the tank.
Nothing has yet been killed.  I have a healthy population of amphipods that
could be feeding one or both.  If they were small to begin with would they have gotten much bigger in 6 months?
<Likely so... most only get to less than an inch and a half total length>
I have herd stories of people having mantis shrimp in a reef and it never killing fish.  Nothing has died should I just wait and see?
<I would, yes>
Could I have lucked out?  I have a healthy population of coral too.   My rock is secured to a frame so I have good circulation in front and back (at your
suggestion).  So, the only thought I have is to slowly pull out rocks 1 by 1 and rotate them into the fuge until I hear the popping coming from the fuge.
My concern is that I will stress the heck out of the fish pulling a new rock out every night and of course anything with coral attached will take a potential hit.
<You are wise to consider this "cost" here... the "alternative hypothesis"... and to choose the null... to do nothing>
My final question is w/ respect to adding fish given this situation.  I am only planning on adding a few more. 1 Flame Angel (of course my coral and
clam may hate me), 1 mandarin goby when the time is right, and a couple of open water swimmers: fairy wrasse or 2, a Chromis or 2, etc...
Thanks as always, you all are the best. Oh and Tom from the Fish Doctors in Michigan sends his best (I got lucky and now have a great LFS).
<Ahh! Please do mention back to Tom that I say hello as well! Bob Fenner>

Hitchhiker - Mantis Shrimp
Hi Crew, I recently purchased 45lbs. of uncured deco live rock, which I am curing in a 20 gallon tank.  Off and on I hear clicking sounds coming from the tank and I am guessing that I have either a Pistol Shrimp or a Mantis Shrimp in one of the rocks.  I have never seen the shrimp, but from all I've read, this seems like the logical explanation for the clicking noise.  My question is, should I try to remove this shrimp.  The noise isn't really loud enough to be bothersome, but I fear that if it's a Mantis Shrimp, he will do damage to his future tankmates.  Is there any way to id the shrimp if I can't see him?  Should I not worry about it unless it becomes a problem?  If you do suggest trying to remove him, how would I go about this? Thanks in advance for any help you can offer...you guys are awesome!!
<If there is a clicking sound it is likely a mantis shrimp. The easiest way to remove him is to suspend the rock above a bare bottom tank and catch him/remove the rock when he comes down to eat. If it is a mantis he could cause damage and or eat any future tankmates.  When you catch him you might try "advertising" him on the WetWebFotos chat forums, there are some folks that love keeping Mantis Shrimp and will purchase him from you.  They can be quite beautiful.  There is much more on WetWebMedia.com, search on mantis shrimp in the google search.   Craig>

Re: missing fish!
I have a 75 gallon salt water tank with ten fish (all compatible and reef safe).  
<How do we know?>
2 days ago one of my cardinal fish vanished! Then yesterday the same thing happened to my scooter blenny. Besides that I've had 1 banded starfish ripped apart and killed, and now the new banded starfish is missing 2 legs that were just there. What could be going on? All of my other fish are doing great and my corals are growing beautifully. My water tests which I do once or twice a week continuously come back good. I have live sand and Tonga ridge rock, could there be something hiding in my rocks?
<Yes, likely a Mantis Shrimp. Does your tank make a clicking sound?
Go to WetWebMedia.com, scroll down to the google search engine and type in "mantis shrimp". You have to trap it. Be careful they can injure you, no joking.  Perhaps a crab too.  Craig>

Mantis ID- Stomatopod 2/5/03
Could you please identify the creature in the attached photograph?  
<yep... a small Mantis "shrimp" (Stomatopod)>
It came in with a shipment of live rock from the Gulf of Mexico. It was about an inch long but has doubled in size in less than 4 weeks.  It is very elusive and hides at the slightest disturbance. The tail area is flared like a lobster.
Robert Pierrelee
<you will likely need/want to remove this predator on small invertebrates. Fears about its presence in the aquarium are largely overstated... still, it can destroy a lot of small and desirable life forms (snails, small fishes, other crustaceans. Please browse info in the archives about trapping such creatures. Anthony>

The Mystery Killer
Greetings crew,
<Scott F, on call today>
Thanks for your help in the past.  I'm new to the hobby (4 months) and appreciate the guidance and reassurance.
<We aim to please! Glad we could help!>
I have a 30G tank with 40# live rock, single 17 watt Zoo Med Reef Sun 50/50 lighting (12-hr on timer), H.O.T. Magnum Pro filter with activated carbon and bio-wheel, Berlin Air-Lift protein skimmer (added two weeks ago), and the following (known) inhabitants:
<I like the "known" preface!>
Fish:
1 Dascyllus melanurus, 1.5 inch (4-stripe damsel)
1 Amphiprion ocellaris, 1.5 inch (Ocellaris clown)
1 Centropyge bispinosus, 3 inch (coral beauty)
Inverts:
4 scarlet hermits
3 Lysmata wurdemanni (peppermint shrimp)
3 Turbo snails
1 Lysmata amboinensis (scarlet skunk cleaner shrimp)
1 Mithrax sculptus (Emerald crab)
1 Condylactis pink-tipped anemone
Lots of tiny (Mysid?) shrimp - more every time I look.
<Cool- sounds like mysids!>
The turbo snails were added about three weeks ago, the coral beauty and anemone just one week ago.
<Remember to quarantine all future fish purchases, okay?>
The rest have been in the tank for about 3 months.
I feed Tetra Marine Granules (softened in water for about 30 seconds
first to make them easier to eat for the fish -  in retrospect, not the best food choice for my small fish) daily, and flakes about every other day, either Spirulina or Tetra Marine flakes.  Occasional frozen brine shrimp.
<Try some frozen Mysis shrimp, or "Formula" foods- they offer more complete nutrition than brine shrimp>
Latest water numbers (typical for my tank - no major deviations):
Temp:               77 F
pH:                   8.2
specific gravity:  1.023
ammonia:          0 mg/L
nitrite:               0 mg/L
nitrate:              30 mg/L (can't seem to get this to go down)
About once a week I add 2 ml of Seachem Reef Iodide, though I do not measure it in the tank.  I change 5 gallons about every 1.5 weeks.
<Make it a bit easier- try smaller (like 5% of tank volume) changes twice weekly- that may help with the nitrate reading a bit>
I should preface this story by saying that there may be additional,
unintended inhabitants in the tank: shortly after adding my last batch of live rock (15# on 11/07/02), I think I saw a small (1 inch) pistol shrimp - he came out of the new rock quickly, grabbed a piece of food, and hustled back in.  I've only ever seen it that one time and am starting to wonder if I imagine it, but I don't think so.
<I hope you are...but if you saw it...could be there...and could be a problem!>
I distinctly remember seeing one claw being larger than the other, besides that, it looked similar to the peppermints - not easily confused with a mantis shrimp.  I haven't heard any distinct clicking sounds coming from the tank, and I've tried to sneak up on the tank a few times when the lights had been off for a while but haven't seen anything major.  There is also at least one bristle worm, maybe two inches long and 1/8 inch wide.
Here's the story: During the first week of January, I was away on
vacation, so my brother stopped by to feed the fish, using individual food packets I'd previously measured out.
<Smart idea!>
I was gone 7 days, he ended up coming by four times to give them a single packet each time - I told him not to worry about missing a day or two, better to underfeed. When I got back, he informed me that one of my clowns just disappeared, and I have found no trace of her since (I had two then, in the pre-coral beauty days).  Not to ruin the ending, but I also had two Emerald crabs
at that time (pre-snail and anemone days).  The odd thing is that of the two clowns, the one that is still around is the one I would have expected to have fallen victim to a predator - he apparently has a swim-bladder defect, and cannot maintain neutral buoyancy (he was tank-raised).  He seemingly gets so tired constantly swimming up that, several times a day, and all night, he just lies on the gravel, a prime target for a hungry Emerald.
<Yeah- you'd think head be the "Vic" (okay, I watch too much "CSI" on TV) >
The one that disappeared swam normally. I suspected the mysterious shrimp first, so I took out the rock I saw him in months ago and put it in a bucket for a few days, with a piece of scallop in there to temp him out.  The food (replaced daily for freshness) was not eaten in a week, so I gave up and put the rock back
in the tank. I then assumed it was the Emeralds, and decided to keep an eye on them (there were two at that time, remember).  Of the two, one was clearly bigger and slightly more aggressive, but never, to my knowledge or witness, posed any real threat to the fish. So fast-forward to this week - I have a tank divider in place to let the frisky 4-stripe damsel get acclimated to the coral beauty.  The two Emeralds were on one side, together with the 4-stripe, two snails and two peppermints, but on the other side from the suspicious rock. Yesterday I saw the carcass of the larger, more aggressive Emerald, lying upside-down on the gravel.  I've been fooled by crabs molting in the past, mistaking them for having died, but this one I am 99.9% sure is really dead.  I removed the carcass - it seems the right weight etc, has no "escape" hole that she could have gotten out of. In fact, the
only thing differentiating it from a living crab (besides the fact that it is dead)
<Yes- being dead is generally the best indicator that it is dead! LOL>
are that the abdominal cover (the baseball-catcher
chest-protector like thing between its legs on the underside) has been loosened so it is only attached posteriorly (exposing some clear muscular looking tissue), and, most interestingly, seems to have had a hole punched though it!  The hole seems like it required some force to create - like a puncture wound right through the abdominal shell. I can't imagine that the other Emerald crab could have done it - taking down a larger, more aggressive crab.
<Neither could I...I vote for the mystery shrimp>
I can't imagine that any of the known inhabitants in the tank could have done it, actually. So the only explanations I can think of are: 1) the crab died "naturally", due to an unknown water parameter, poor nutrition, etc, and the other crab and/or peppermint shrimp scavenged the carcass, creating the wound;
<Possible, but too many similar coincidences recently>
or 2) an unknown murderer is living in my tank, picking off my pets one by one.
I have still seen no sign of the clown (no measurable water changes
either, that would indicate a hidden decomposing fish), so I assume what ever got it ate it, or, if it too died naturally, was consumed thereafter.
<Both good possibilities>
Have you ever seen a fish just disappear without a trace (in a 30G
tank), and a crab get stabbed to death?  Any advice on how to further investigate/prosecute this case?  I apologize for the length of this question, but I thought it was all relevant.  I appreciate any help. Respectfully yours, Tom
<Well, Tom- based on the circumstantial evidence (that sounds soo cool to say that!), I'd have to believe that you have a nocturnal killer. If it is the "mystery shrimp" (and I believe that it is), you'll have to lure him out somehow with some bait (like the scallop you used before), and maybe utilize one of the commercially available "traps" for this purpose. I used to think that they were a joke until a friend of mine caught a 3 inch mantis shrimp in one! Keep trying to bait this little *&^%$# out, and get him out of the tank as soon as you can. Don't give up! Regards, Scott F>

Mantis menace?
07/19/03
<Hi Tim, PF with you today>
Hi, I think I might have a mantis shrimp, not quit sure. I saw only a glimpse of him peeping out some hole in the rocks, and he seemed to travel from hole to hole, and in different rocks. But, what I did see was this green head with long green eyes that rotated opposite of each other. He never comes all the way out, so I can't get a good look at him. The LR I bought was from Tampabaysaltwater.com, and I've heard they're known for it. I do hear a clicking sound but haven't seen any dead snails, and the tank has been cycling without fish for two months now. Is there a way to lure him out so I can see him, or an easier way (I know there is no easy way, unless he breaks the glass) to get him out. I don't want to buy traps that won't work, and to find him in a particular rock means I would have to use my hands. I like my fingers as they are.
Please help.
By the way your new book is next on my list.
Tim Wagner
<Well Tim, first off, the bigger worry is your LR falling on your glass than that mantis breaking it. The mantis breaking glass is a tale that grows in the telling. It has happened, but the mantises weren't the little ones like you have but an O. scyllarus that was at least 5" long - and there's a lot more power in 5" of mantis than in 2". As for TBS live rock, Dr. Roy Caldwell (a mantis <Stomatopod is their correct name> expert conducted an informal survey and found that most people find 1 mantis/hundred pound of rock regardless of the source (including his own work in the wild), I've had LR from Fiji that the LFS "guaranteed" to be mantis free, the  mantis didn't listen. Be all that as it may, the little bugger is less of a threat than legend has it. Depending on the size of snails and hermits you have, it may not actually be a threat to them. I can understand your fear though, as they are predacious, and very intelligent predators to boot. I would recommend that you go here: http://www.blueboard.com/mantis and read up them. There are sections on the site about mantis removal, and if you're so inclined, their care. If you're up for, I'd advise setting up a separate tank (a 10g nano is plenty big) and keeping the little bugger, or putting him in your sump (I know a number of people who've done that with theirs). Hope this helps, PF the self professed stomatophile. BTW, the new book has a section on mantis shrimp in it, so you can read up on them when you get it.>

Mantis menace?
07/20/03
<Hi Alastair, PF with you tonight>
Hi, I believe I may have a mantis shrimp, but am not certain. Need some advise. There is clicking noises coming from the tank, it will normally be one click, or occasionally two. The thing is I just cannot find it, I have removed each piece of rock and dunked it in fresh water for three minutes, but no Mantis has been forthcoming. What really bugs me is that all I have achieved is damaging and killing some of the other life on my rocks. Is it
really a mantis, or could it be something else?
The tank is a 15 gallon with around 20 lb rock, you would think it would be easy to find whatever is doing it in a tank this size.
The tank was only established around 4 months ago. Around 2 months ago I introduced around 20 small ( 1/2 to 1 1/2 inch ) shrimp of a type that can be caught locally (New Zealand). Most of these have vanished without trace.
One jumped out but the rest just disappeared.
Cheers, Alastair
<Well, it could be a mantis, or maybe a pistol shrimp. Check here for more info about mantises http://www.blueboard.com/mantis. The FW dip is pretty much like nuking your live rock, and I would never recommend it. Try feeding your tank live brine shrimp, or something similar. You may also want to wait up, and using a flashlight with a red filter check and see if you see it moving around after lights off. There are also commercial traps out there. Good luck, PF>

Re: Mantis Menace
07/22/03
Hi PF, Hey, Thanks for the speedy reply.
<Hello again>
Great News, I got them, they were pistol shrimps. I saw one as a snail was crawling on the rock, something appeared and clubbed it of the rock, and then retreated. Now at last knowing where they were I was then able to take out the rock and dig out the hole with a screwdriver, they were both in there and I pulled them out
with tweezers. They appeared to be a mated pair living in the same hole. The female was loaded with eggs. They are small, about an inch long, but still make quite a discernable click.
Checked out that web site you sent me and was able to identify them as pistol shrimps. They are supposed to be relatively harmless, but I would still rather do without them.
You were right about the fresh water being bad news, it really has damaged my rock life, also I was pretty amazed, I only dipped the rock they were in 24 hours ago, and yet the pistol shrimps seem fine.
<If they're still alive, you could set them up in their own display, a 10g or 20g, or perhaps sell them to an LFS. Mated pairs are rarely available, I'm sure someone would like to take them off your hands. It's nice too, that they weren't mantis shrimp, takes some of the heat off my favorite crustaceans. ; ) >

Clicking Noise
>Hi
>>Greetings, Simon.  Marina today.
>I have a two foot salt water tank.  It is stocked with the following:
1 Clown Fish
1 Coral Banded Shrimp
1 Dottyback
1 Blue Tang
Some live rock
There has been a clicking noise (on occasion) coming out of my tank for some time now (around 5 months).  I am not sure what it is, but I have been told that it could be a Mantis Shrimp - which is supposedly something that can smash the glass of the tank.
>>More likely a mantis shrimp, less likely it will smash the glass than it will take other residents.  It's also possible it's a pistol shrimp, but far *less* likely.
>I have read your FAQ and info pages on the Mantis Shrimp and I found it quite informative, however I just wanted to ask the following:
1) I can't find this Shrimp, so is it possible that any of my other stock can click?
>>Yes, it's possible.  However, just because you can't find it doesn't mean it's not there.  They're quite intelligent and crafty little bugs.
>I have been told that Clownfish do some clicking.  The clicking sounds like a coin tapping against the class.
>>Yes indeed, but I've yet to hear them make any noise that's audible from outside the confines of the tank (think of the many catfishes we keep that make similar noises, yet few can be heard from outside).
>2) I have noticed a worm like creature on a live rock.. it looks like a worm and I couldn't really see a head.. it was very quick. I was about to stick a net in and try to catch it, but as soon as I touched the glass it went off like a bullet into the live rock.   If this is the culprit then it is possible for me to take this bit of rock out.  I only managed to see it at 4:00am one night while I had a hangover.
>>Hhhmm... everything's questionable when viewed during a hangover.  J/K.  A worm can't really click, being soft.  However, if you are able to determine *which* rock the mantis/clicking suspect is living, you can remove it to a bucket or other container, dip it in freshwater and it will probably high-tail it outta there.
>I haven't managed to see anything in normal spectator hours :)  I don't know if it is possible to set a trap for it?  Because my coral banded shrimp is pretty quick - he will go for any bait lying on the ground.
>>They are quick (though not too quick for me and my net!), but you're not trying to catch the CB shrimp, are you?  There are many mantis shrimp traps available online, do a Google.
>3) If it is a mantis shrimp - my concern is that it could crack my tank???
>>Again, HIGHLY unlikely, what is likely is residents may begin to disappear.
>Is that a true concern?  Another important concern is my fish - but so far no incidents.
4) Also, another thing that happened the other day (off the topic) - My Coral Banded Shrimp (Lenny) shed his shell.  He has done this a few times now.. It is quite an impressive process. Anyway it seems as though one of his legs (or arms) is a bit weak or injured.  Is it possible that he could have shed prematurely or something went wrong?
>>I would suppose that he's in need of some mineral supplementation--calcium and iodine are two I can think of off the top of my head.  Consider dosing calcium (do test your tank first) and/or iodine.  Search our site for information on these, as well as Googling.
>He hasn't really been himself. A bit reserved.  The Dottyback and blue tang are new additions, and he was going after them a bit. Is it possible that he shed because of these new additions?
>>No, he shed because he outgrew his exoskeleton.  This is a good thing, but do be sure these animals have sufficient and sufficiently available biominerals.  I do hope this helps, and best of luck!  Marina

Praying it's not a mantis  6/15/03
<Hi Simon>
Hi I really hope that you can help me with this.
I am an experienced fish keeper but a beginner as far a marine tanks go. I have a small 80 gallon tank which is some six weeks old. I have been slowly adding live rock and have been very happy to gain a few creatures that came with it. The most exciting of these was a brittle star, it was only small, about the size of a large coin and appeared a couple of weeks after the last piece of rock was added. I was surprised that it survived the nitrite surges as the filter matured.
Anyway I was pointing out the brittle star to a friend who was visiting when something partially emerged from a hole in the live rock, grabbed the brittle star and pulled it into its hole. The "something" was about 2 inches long but that is only the part that was visible. It was red in colour with spikes along its body. A few minutes later it was hanging out of its hole with bits of the dead brittle star left on the gravel bed.
Can anyone suggest what this could be? I have no intention of adding any small invertebrates to the tank, it is intended as a fish only tank for a pair of Tomato Clown fish so what I really want to know is can I leave it there?
Any help would be much appreciated.
Thanks
Simon
<Well Simon, I'd be willing to bet the farm (if I had one) that you have a mantis shrimp. The Lurker's Guide to mantis shrimp is an excellent source of information http://www.blueboard.com/mantis and here http://www.wetwebmedia.com/marine/inverts/arthropoda/stomapods/mantisshrimp.htm . Stomatopods are fascinating animals (and a personal favorite of mine). Now as for letting it stay in your tank, well, a lot depends on what type of mantis it is. If it's a spearer, get it out. If it's a smasher, you could keep it in your tank if: 1, you feed it regularly (krill, open a small clam, pieces of fish or squid, etc.), and 2, you buy a pair of larger tomato clowns (not under 3"). Be aware, that it will probably eat any clean up critters (snails and hermits) you get. As for eating your brittle star, well that sounds like one hungry mantis to me. I've never heard of them eating brittles before.
Well, have a good night, do some reading, and write back if you have any questions, PF>

My, what dark oval eyes you have...? (02/29/04)
Hey crew,
<Hi! Ananda helping out tonight, playing a hunch on this one...>
Thanx for all the help so far.  You guys take a lot of the stress out of caring for a new tank.
<We aim to help!>
This one is going to be hard and unfortunately I don't have a digital camera. Either way I can't see much of the new creature anyways. I looked through the inverts section and didn't come across anything like this little guy. Today I noticed to antennae sticking out of a hole.  At first thought they were just a tube worm but I noticed that each one split into two at the ends. I also noticed that there were two little "eyes" looking around. The shape of the eyes were oval and very dark.  
<Right now, my brain is saying "Cool! He might have a mantis shrimp!" Check pix at http://www.blueboard.com/mantis/ and see if anything looks familiar.>
I didn't get to see any of his body as he is too timid to come out of the hole in the rock.  
<Yup, sounds like a mantis.>
I noticed an empty hermit crab shell next to the hole....hopefully the crab wasn't eaten....and it definitely isn't the hermit in the hole.  
<Well, the hermit may have switched shells.>
I got home tonight and noticed that the hole had been filled in.
<Yup, they do that, too. Cool little critters for a species tank.>
Being curious and maybe not altogether smart I poked it the handle of a net. At this time a piece of shell, clump of sand (not sure what) fell into the hole. The little guy poked his head out and looked around and then put the piece back in place.
<I would, too, if you banged in my door. ;-) >
Unfortunately it can't describe him much better than that as I haven't been able to seem out of his hole.
<The behavior sounds very much like that of a mantis shrimp.>
IF you can identify this or even point me in the right direction to try and identify him that would be great.
Thanks again,
Todd Hawman
<Our resident mantis fanatic is lurking about the forums again. Try posting at http://wetwebfotos.com/talk on the Marine Invertebrates board with more descriptions, if you can, and see if P-F thinks you've got a mantis. You might want to put a piece of frozen shrimp next to the place you saw the creature so that it's less likely to go for a moving target (aka a hermit crab). --Ananda>

Mantis Shrimp? 2/24/04
In the last week or so I have lost 2 Fire Fish Gobies, and a Cleaner Wrasse. All within 48 hours of purchase.. The Wrasse Within 12 hours. I do have some  fairly new rock, (maybe in display now for 6 weeks). I have not noticed a loss in hermit crabs, maybe a couple snails, but I always tend to lose a  snail or two every couple months. In the tank are 2 ocellaris clowns whom I have had over a year. As well as a LT anemone whom I have had over a year.  The Fire fish and Wrasse were about 3" long. I have heard no clicking at night and have stayed up since losing the first Firefish. Yesterday though I saw what could have been a pretty small Mantis. at most he was 3/4" long. Is this big enough to take down the fish mentioned?
<If it was a mantis, it would not stay that small for long with all that food!  Seriously, though, it is unlikely that such a small mantis could capture those fish, and from your story, I doubt you have a mantis.>
and if so could the clowns have been protected in the anemone since they sleep in it? Or could the anemone be the culprit? It does not completely close up at night anymore like it did when I first got it. During the day it is about 13-14" in Diameter and stands about 6" tall. I would think that even at night a wrasse
or Firefish would be to quick for the anemone, all losses have come after lights off, and there is no sign of a body the next day.
<The clowns would probably be protected, but I still don't think that a mantis is your problem.  All of the fish you have lost are potential carpet surfers.  Have you checked the floor behind your tank and any overflows for evidence that they may have jumped?>
How would I go about catching such a small mantis. I have already tried "dunking" in high salinity water all my LR.  <High salinity, low salinity and soda water have all been suggested to coax mantis out of hiding places.  All of these hare hard on the desirable life on rock and should be avoided.  Traps are commercially available or can be fashioned by cutting the top off of a small soda bottle and inverting it into the bottle.  Weight it, bait and wait over night.  Weighting and baiting an old pair of panty hose has also been suggested since the mantis will get entangled while trying to get the food.>
I also have a "monkey shrimp", a Coral Banded shrimp Both I have had for at least 6 months.  <More anti-mantis evidence!  These critters would be much higher on the potential prey list than fast moving fish.  Their survival is a good clue that a mantis is not to blame.>
One more thing, I have a nice  piece of pipe organ coral that is quite large, it seems however that I missed a couple Aiptasia, on the new LR and 2 Aiptasia have since climbed up through the "pipes" and are now sitting smack dab in the middle of the
coral piece. one is quite large maybe 1 1/ 4" Peppermint shrimp have been no good since I think it is to big for them, I can not cut it off since it pulls itself into the "pipes" when I get near, or pull the coral out. I am starting to think I am going to have to cut the coral, but how? its about 4" deep, 6"x5" across the top. the Aiptasia is about 2" from the edge of the coral. My local LFS said to buy a copperband Butterfly, I am afraid it will eat my other corals, he said that they "target Aiptasia first" is this true?  I have not heard that before. My other corals include Xenia., Green star polyps, and asst. leathers and mushrooms. thanks again for all your help the past year.  Aaron
<Glad to help Aaron.  Copperbands are very delicate fish in captivity.  Even the survivors will often refuse to eat Aiptasia, or will only eat them when very hungry.  I disagree that they "target Aiptasia first".  I don't think any of your corals will be at too much risk, except for the pipe organ.  Your best be is to try careful peroxide injection.  Your coral may suffer some collateral damage, but with care, it will be no worse than the Aiptasia will cause.  Best regards.  Adam>

DSB, anoxic dilemma? 3/18/04 (Perhaps the term hypoxic for the mid-zone)
Hi bob,
<Anthony Calfo in his stead>
I have a question regarding depth of substrate. You mention to use 1" or less (completely aerobic) and 3" or more to create an anaerobic environment for denitrification. You mention any substrate thickness in between those parameters would cause anoxic havoc. I'm a little perplexed by this.
<me too... I am nearly certain Bob would have never said this... and I agree with part of the assertion, but would not use the phrase "anoxic havoc". Where is this from  my friend. Our book, the archives, etc?>
Firstly, the anoxic environment created by 2 inches is still an anoxic environment and I do not understand how it differs from 3 or more inches of substrate?
<part of the misunderstanding indeed... I do not believe a 2" substrate can get adequately anoxic for NNR... and if you'll take the time/years to use and study DSBs, the you will see that 3"/75 mm is the bare minimum for effective NNR... hence the rule>
Wouldn't both anoxic environments (in between 1-3 inches and 3" plus) create H2S?
<not the goal at either depth, and regardless cannot be assumed without an address of nutrients sunk to feed/fuel the conversion>
How is it that one is safer than the other? I'm sure there is something I am missing here,
<yes>
I just want to understand what that is.
<me too>
Please do not refrain from becoming really technical in order to get the point across (that is if you have time to), that is, layman's terms are not necessary, nor is the need to explain technical terms.
<no time alas at length... but please let me direct you to the extensive detail and discussion we have of it in our "Reef Invertebrates" book or the free wetwebmedia.com archives (much info there if you will take the time to sort through it)>
My last question. Why would one want to rid Live rock of its biodiversity...i.e.. removal of mantis shrimp...etc. How would they be detrimental to 1) fish only tanks or 2) reef tanks? Are these animals prone to being hosts of pathogens detrimental to animals/organisms in the tank more so than animals commonly kept in aquaria? Or do they just eat factors important in maintaining good water chemistry? Why are they deemed unwanted?
<depends on the species. You must ID that first. Spearers catch and kill fishes... even the smallest/"safest" smashers instead still mow through other desirable invertebrates like gastropods. Judge them by what you deem more useful in your aquarium... purchased snails/fishes... or expensive meals>
Thanks so much! Mars
<rock on... Anthony>

- Is it or Isn't it? -
I think there may be a mantis in the new rock because there is a lot of clicking coming from it almost all the time. <Then chances are it's not a mantis shrimp - what is more likely is that you have an Alpheid, a snapping shrimp. Mantis shrimp just don't click that often, compare with some snapping shrimp which click constantly. No worries.> I just put some egg crate over the top. doesn't seem to effect the light amount much of all. <Good deal... now you're prepared for leaping wrasses.> Thanks!!!
<Cheers, J -- >

- Is it Or isn't it? It Was! -
it was a mantis!! <I should have known better - the live rock from TBS is a well known source of mantis shrimp.>
I came home tonight and between a couple of coral polyps was this big reddish brown head protruding from a hole. I immediately removed the rock and put it in a bucket of fresh water. I was taking no chances. I soaked it for 10 min.s and shook the rock and out comes this huge mass of eggs!! <You'll need to cure this rock all over again - you've wiped out everything on it...> then a 2.5" mantis came out very dead. <Makes sense.> I then took the remainder of the rock and soaked it too. If that thing had gotten in my main tank it would have been a disaster. and with those eggs it was like a reef tank version of Alien waiting to happen. all I can say is better half dead live rock than putting that thing in my tank <Uhh... it's not half dead, it's all dead. Cheers, J -- >

- Is it Or isn't it? It Was! Follow-up -
thanks for everything!!  Gotta tell you. I left the rock in fresh water for a full 20 min.s and the barnacle life is still waving a way!! and the mussels that look like rocks are still alive. <Makes sense, both of these are able to shut tight with a small supply of water... other items will not be so lucky.> I hope I left the rock in fresh long enough to kill any bad guys
<Well, if you wiped out that mantis shrimp, then you probably got anything else like it.
Cheers, J -- >

Peacock mantis shrimps
Hey there! I've just visited my LFS and saw a very interesting mantis called
a 'peacock mantis'. How big do these shrimp get? Are they smashers or
spearers? The label didn't say how much it cost, but how much should it cost? I'd
appreciate any help.
<Please see here: http://www.wetwebmedia.com/marine/inverts/arthropoda/stomatopods/mantisshrimp.htm and the linked FAQs files (in blue, above) re. Bob Fenner>

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***

Maybe a mantis?
I think I might have a mantis.  I've read your pages on the mantis but
still am unsure.  Maybe it's a pistol.  Here's the symptoms:  new, cured
live rock and sand, new setup.  JBJ Nanocube (12g) with about 7 small
hermits (can never see them all at once, so I'm not sure), and 4-5
Nerites snails, a bumblebee snail, and one peppermint shrimp (just added
last week). The tank has been setup about 2 months now and that's all
that's in it - taking it very slowly to be sure all is ok.  During the
daytime I hear clicking sounds, like glass marbles hitting glass. << More like mantis, less like pistol. >>  Its
only once in a while, very sporadic and usually only a couple clicks at
a time.  I've also seen something burrowing in the rock, digging,
spewing out white, chalky particles.  My rock is very porous with an
intricate network of caves and tunnels throughout.  Pretty sure I saw
the little guy one night.  I was hoping all along the popping sounds
meant pistol shrimp so I was all set to see tentacles and a claw, etc
when, to my disappointment, I saw two little eyes at the ends of long
tentacles rotating about, looking back at me.  Bummer.  Mantis.  But
here's the thing, with all these crabs and snails and even a peppermint
shrimp, I've had no deaths.  He's been in there since the tank has been
set up.  I have found some shells with holes, but I'm pretty sure I'm
not missing any crabs.  The life in my sand is quite robust with little
fleas and bugs crawling all over the place.  Could it be he's just
feeding on them and I do not have to worry? << Well it depends on what you mean by worry.  I'd say don't worry.  Yes he may eat a few things here and there, but that is to be expected. I'd think in a 12 gal tank you could remove him if you really wanted to. >> I guess I'd like to catch
him, just to be sure.  With the tank pretty much empty, I could also
just pull out the rock and dip it.  But so far, it seems, no harm, no
foul. << Exactly what I was thinking. >>  However, I do plan to add maybe a goby and other critters
(non-fish).  So, maybe this is a good time to get rid of him . . . .
what do you think?  Is it mantis?  Pistol? << I think you should bring this up on the www.utahreefs.com/forum site.  Get some local input.  Sounds like a mantis to me, but as you said that doesn't seem to be anything to be concerned about.  Also, if you do get rid of him you'll find a buyer there. By the way, I too am in SLC would like to come get some pictures of him if I can. >>
Thanks! << Stay in touch. >>
Tom
<<  Blundell  >>

Fish predator - mantis shrimp?
Hey Guys! I've had my tank for approx 11 months now, its a 5ft x 30" x 24" tank with some live rock. I've been stocking my tank slowly with fish here and there, but every now my fish just swim to the back and then they disappear overnight. so far I've lost a Naso/lipstick tank, 2 purple firefish gobies, and an Anthias. I never find their bodies, they just literally disappear over night ... I test my ammonia, nitrite levels and they seem to be okay (i.e. usually 0 within the few days) At the moment, I have quite a large Radianthus anemone and some coral... at first I thought the anemone would've eaten my first
disappearance (even though unlikely) but never thought much of it afterwards
<doubt it is the anemone.. sounds like a large mantis shrimp to me>
However, I was told that some shrimp are predators to fish. And I do hear a very very loud clicking sound every now and then (maybe once or twice a day). I've realized that that sound is coming from some sort of shrimp ? <yes probably a mantis shrimp>Is it true that this shrimp could be the reason of my disappearing fish? <yes>and if so, how do I find it and rid of it .. is there anything out there that eat these shrimp ?<you can either trap it...or purchase a large triggerfish or wrasse...they will quickly make a meal of him. Good luck, IanB>

Bloated gashed clown
Hello
<Hi there>
I have had a maroon clown in My 200 gal FOWLR for 4 months now. I noticed early last week a gash in his side. he has eaten well since and other then the blemish he seems fine.
<Likely a bump in the night...>
yesterday he seemed a little bloated but it isn't unusual to see him that way after feeding. he seems to take in air during surface feeding and kinda "floats" but then seems fine.
<They are called "clowns"...>
Today I noticed a similar gash on the other side and he seems more bloated. he is still eating.
<Maybe not a bump, but a crustacean would-be predator...>
I thought it my be a mantis shrimp. I got some new rock a couple weeks ago but I have never heard any clicking whatsoever. The gash almost looks like it could be from the inside out. I'm not sure what to do. any ideas?
<I would isolate this fish (in another tank or in a floating plastic colander) and try baiting out whatever might be hidden in your rock. Please read here: http://www.wetwebmedia.com/marine/inverts/arthropoda/stomatopods/mantisshrimp.htm
and the Related FAQs (linked, in blue, at top). Bob Fenner>

Re: bloated gashed clown
Is it possible to have a mantis in the Tank with no clicking??
<Yes. Clicking is far more common with Alpheid shrimp/s... Some Mantis can make periodic loud smacking sounds... the "smasher" varieties>
we haven't
heard click one also, I have 5 green Chromis, an algae blenny, and 2 tangs
with no marks??. I'm gonna keep my eyes peeled and keep watch before I don
the scuba gear and capture the clown out of the 200 gallon
<It still may be that the clown's marks are from other cause... even repeated swimming into sharp objects... Bob Fenner>

Have we Mantis? & Chalk Bass
Hi,
<Hey, Mike G here>
Is there a possible way in finding out if my tank has a mantis shrimp living inside of it? Is a chalk bass a ideal fish for a reef tank, and if so how many is a good number to purchase, and what sort of tank mates make feel comfortable?
<Hmm...For some reason I don't think those two questions should be asked in the same sitting. Chalk Basses make ideal reef inhabitants. They stay small, are relatively docile, are hardy, and don't nip at corals. However, mantis shrimp do NOT make ideal tankmates of chalk basses, and certainly do not make them feel comfortable. Though, to find out if you indeed do have a resident mantis, you could simply go ahead and purchase a chalk bass. If it disappears without a trace, then you have a mantis. If not, then your reef is already stocked with a perfect inhabitant.  
(I DO hope you realize that I was just kidding)
In all seriousness, check the following links for more information on mantis shrimp. Then, once you are sure that you are mantis-free, open up this email again and check the next links, separated by a line break, which contain information on chalk basses. Good luck, Mike G.
http://www.wetwebmedia.com/marine/inverts/arthropoda/stomatopods/mantisshrimp.htm 
http://www.wetwebmedia.com/mantisfaq2.htm 
http://www.wetwebmedia.com/serranus.htm 
http://www.wetwebmedia.com/serranusfaqs.htm > 

Follow up on Chalk Bass and Mantis
Hey, thanks for the links I understand now.
<No problem. Glad I could help.>
I am not worried about having small mantis shrimps in my larger display tank, because I have a pair of extremely large sunrise Dottybacks. I was once troubled with a load of bristle worms, but the pair of orchids, sunrises, and one sixline has kept the population in control.
<They certainly have a habit of doing that. Just FYI, bristleworms are not necessarily bad to have in a reef.>
However, in my small tank I've lost two fish. I stirred the sand and everything else.. just not a single trace. I think the flame Hawkfish did it, but it couldn't possibly consume a lawnmower 
blenny( the Banggais are fine)....
<I seriously doubt the flame hawk did it, unless you found corpses and you've witnessed the hawk acting aggressively. Do you have any brittle stars, by any chance? They have a habit of consuming fish. (But so do mantis)>
This is troublesome but thanks for taking your time..
<Not a problem. I wish you the best of luck. Mike G> 

- Possible Mantis? -
The WWM Crew,
I have some problems with my 125 G reef tank (75 G sump). Recent deaths/disappearances include: 2 Purple Firefish, 1 Blood Shrimp, 1 Skunk Cleaner Shrimp, 10 Peppermint Shrimp, numerous hermit crabs (red & blue legged), and numerous snails. 
<I'd be checking on the floor behind the tank for those fish - they can and do jump out.> 
Also missing in action is my tiger pistol shrimp who is/was mated with a Blue Spotted Watchman Goby- although he has gone underground for long periods of time before. The goby seems to be in perfect health. I hear clicking noises at night- which could very well be my pistol, but I have a bad feeling that I have an unwelcome guest in my tank... 
<Well, just for starters, most mantis that "click" (smashers) are for one, not nocturnal (rather, the large majority are not nocturnal) and two, don't usually prey on fish; snails, crabs, shrimp yes. Also, the a large portion of the smashers are under two inches, so if you "had" a smasher, you would have seen it by now or wouldn't need to worry about it so much.> 
The tank is a new set up, but I used water, substrate, and live rock from my other reefs (35 G & 20 G). Also, added around 80 lbs of fully cured live rock from a reputable LFS.
I bought a trap, but have only managed to catch an emerald crab and the goby (twice). 
<Mantis shrimp are smart enough that you can use any given trap mechanism exactly once - they are quick learners.> 
All my fish seem to be very healthy. (White Cheek Tang, Orchid Dottyback, 3 Flasher Wrasse, 2 Ocellaris Clowns)
These deaths did coincide with the addition of 3 medium sized emerald crabs (AKA suspect #2). <And also worth of your suspicion.> 
I also found a hitchhiker urchin around the same time (AKA suspect #3). 
<Hmm... urchins don't really eat much more than algae, and certainly can't move quickly enough to catch a fish unless the fish were already dead.>
Whatever it is, the snails were decimated rather quickly once the onslaught began. 
<Think this is coincidental... snail populations often thin out all on their own and may have nothing to do with why you lost the fish or other invertebrates. Mantis shrimp are wily predators, but they are not ravenous or unmitigated killers like the creatures in the movie Aliens. They typically only need a decent meal every couple of days and would not kill other stuff for fun or the sport of it.> 
Both cleaner shrimp acted strangely a day before their deaths. The usually very timid blood shrimp sort of went into convulsions for about 20 minutes on the substrate in the front of the tank and the skunk cleaner was antennae-less hours before I saw the tang eating his carcass. I think the tang ate him post-mortem. I hope.
My parameters are so perfect that I am thinking about buying another test kit! My pH is @ 8.2 and my dKH @ 17. Lighting 3x175 W MH 2x96 W PC Actinic. I add a capful of Kent Marine Iodine every other day, basically following their recommendations, at the same time I add Calcium, Coral- Vite, Strontium & Molybdenum. I add calcium (capful) daily, and Essential Elements once a week. 
<Think this may be the clue we need - I don't recommend that anyone add things from bottles without testing first - have you tested for Iodine, Strontium, Molybdenum? If not, then how do you know you need to add them? If you're just going by the recommendation on the bottle, then keep in mind that it is in Kent's or whomever's interest that you buy more bottles of whatever... don't add anything that you haven't tested for.> 
Berlin Filtration with macroalgae, Red Sea Berlin Classic Turbo.
What do the experts at WWM think? 
<I think you need to re-examine your own husbandry of this tank... I'm not saying you're not conscientious, but that you may have missed something. Shrimp don't usually go into convulsions unless something is wrong with their water. If it were being attacked by a mantis shrimp, you would have seen the mantis - it's not going to expend the energy to attack something and not finish it off right there.>
Also, dumb question... Is it possible that my goby has mated with a mantis? 
<Neat idea, but I highly doubt it.>
Any suggestions would be greatly appreciated... I have far too much time & $$$ invested not to fix this problem quickly.
<As I mentioned... look down other avenues... I don't think you have a mantis shrimp which means the answer lies elsewhere.>
Thanks so much,
BJ Wincott
<Cheers, J -- >