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FAQs about Giant Clam Disease, Pests & Predators 8

Related Articles: Example Chapter from NMA Reef Invertebrates book, on Giant Clams, Tridacnids, A Brief Guide to the Selection and Placement of Tridacnid Clams by Barry Neigut, Bivalves, Mollusks, Lighting Marine Invertebrates,

Related FAQs: Tridacnid Health: Pinched Mantle Syndrome in Giant Clams by Dr. David Basti, Deborah Bouchard & Barry Neigut, Tridacnid Disease 1, Tridacnid Disease 2, Tridacnid Disease 3, Tridacnid Health 4, Tridacnid Health 5, Tridacnid Disease 6, Tridacnid Disease 7, & Pest Snails (Pyramidellids...),
FAQs on Giant Clam Disease by Category: Diagnosis, Environmental, Nutritional, Social, Trauma, Pathogenic, Treatments

Tridacnid Identification, Tridacnid Selection, Tridacnid Compatibility, Tridacnid Systems, Tridacnid Lighting, Tridacnid Placement, Tridacnid Feeding, Tridacnid Reproduction, Tridacnids 1, Tridacnids 2, Tridacnids 3, Tridacnids 4, Tridacnid Clam Business, Bivalves, Bivalves 2, Lighting Marine Invertebrates,

Quarantine for new clams       8/17/19
Hey guys,
<Hey Jeremiah>
Thanks a ton for this site, it has helped me massively over the months I've been involved with this hobby.
<Thanks for your words, we are glad to be helpful.>
I currently have a Maxima clam and am getting two more tomorrow. I successfully kept the current Maxima for about two years and it has doubled in size and done very well.
I am planning on quarantining the two I get tomorrow in a ten gallon tank with a sponge filter and heater. I plan on the duration of the QT to be 4 weeks as the two I am getting are quite expensive and the one which I currently possess is the prize of my tank. I plan on situating each of the clams I am getting in their own piece of live rock (currently dry) on the bare bottom of the tank. The pieces of rock I have picked out should be pretty good long term homes for these guys. I will use a spare led light which is currently in my refugium to provide them light. It worked great up top until the blue lights burned out and then didn't look as good, but the white and other colors are what I need for the photosynthetics anyway. One of the new clams is about six or seven inches and the other is about two. I plan on filling the ten gallon tank, drip wise, with water from my main tank as a drip acclimation method.
<Good technique>
So here is where I'm not sure about the next step. How much ammonia do clams produce and how often should I change the water?
<They produce enough to quickly pollute small water volumes, especially when recently imported.>
I know they consume Nitrates and that leads me to think that maybe they shouldn't have water changes in the QT the same way a fish would. Is this true?
<Not completely true, Tridacna clams do consume nitrates but not harmful ammonia and nitrites. And like any other living marine organism, they produce them...not as much as fish, but they do, so you still have to do water changes during quarantine.>
Assuming I do change the water, my plan was to drain off the water to an inch above the largest clam and then drip water from my main tank into the QT to make up the new water. I was planning on doing this once a week, but obviously if I don't have to change the water I would rather not. I haven't found an answer to this question in your archives anywhere.
<I suggest using a HOB filter filled with old filter material from your main tank such as a filter floss or small pieces of live rock, anything that has been for at least a month in your tank/sump, this way you will allow nitrification to take place in your quarantine tank and ease the clams’ acclimation process, besides you can get by with only once a week water changes, don’t forget to constantly monitor your water levels.>
Thanks a ton for your time!
<Your welcome. Wil.>
Re: Quarantine for new clams       8/17/19

Thanks a ton!
<You’re most welcome. Wil.>

Can you ID these hitchhikers growing on my clam shell please? 1/26/12
Hello Bob, James or other possible responsive crew member,
I have attached some photos of some hitchhikers that must've been on my clam when I got him. They started small and are clearly growing. I have two other of these besides the three on my clam in my tank attached to the live rock. They do not move. Initially when they were little I thought they were Tube Worms or a Vermetid Snail so I wasn't too concerned. Now I'm wondering if they are Aiptasia Anemones
<They are>
or Hydroids. I'm not sure as they seem to
have characteristics of all of these. Please advise. It doesn't appear that they are bothering anything. In fact, as you can see in the photos no matter where I move the smaller clam, he always finds his way right back to the bigger clam and prefers to be adjacent to him for some reason. Anyway, It doesn't look like these organisms were disturbing the mantle on my bigger clam even though they were touching. I was concerned because my husband had one of these hitchhikers on his maxima clam in his tank, and when he removed it with tweezers
<Won't work>
(did not expose the clam to air) the clam later died. I think it was related as the clam was doing fine, and there was nothing to indicate any other reason it should've died. After he pulled it out the clam stopped opening and died within a few days.
In the photos, the smaller clam on the left has three of them growing out of his shell. The biggest organism is in the front right on the clam in the photos and two smaller ones at the top right on the other side of the clam.
I moved him to allow me to touch the organisms so that you could see what they looked like when disturbed, and I wanted to try to get a better photo.
I have a 70 gallon display with DSB and 40 gallon refugium with DSB, Live Rock, rubble, Tisbe Copepods and Chaetomorpha Algae. AquaC EV-180 protein skimmer, and I change carbon in a media bag under the return for the protein skimmer every two weeks along when I do water changes. I have a Wavemaker with Koralia Power Heads, covered with mesh and sponge filters in the overflow box and one power head as well on intake and outtake in the refugium which I clean twice a week. Latest test results
Calcium 420
kH 10
phosphates 0
ammonia 0
nitrates 0
ph 8.4 lights on, 8.25-8.3 lights off.
temp 78 degrees
I recently started dripping Kalkwasser, and it seems to be working out fine. It raised my PH slightly, but it was slowly and now it's constant.
My calcium consumption rate is increasing as my corals and other livestock are growing, so I test daily and dose if needed.
<I encourage you to read re Magnesium, test for this as well... often
distorted ratios can cause troubles, in particular when dosing/using Kalk>
My tank inhabitants include:
1 Ocellaris Clownfish
1 Red Linckia Starfish (ordered a Fromia, but they sent me one labeled as a Linckia)
1 Mandarin Dragonet-he eats most of the frozen foods I feed as well as copepods
4 clams, One Maxima and three Crocea
Yellow Sun Corals
Orange Sun Corals
1 Scarlet Skunk Cleaner Shrimp
1 Blood Red Fire Shrimp
Hermit Crabs
2 Orange Spot Nassarius Snails
Bumble Bee Snails
Cerith Snails
Turbo Snails
A few LPS towards the bottom of the tank-one Scolymia, a colony of Trumpet Coral, a purple Blastomussa, Dendrophyllia
Several SPS towards top of tank-Pink Birdsnest and Acropora
2 different Zoanthus sp. colonies
3 different colored Ricordea Florida Mushrooms
1 Hawaiian Feather Duster that has produced several more
Several yellow Feather Dusters that have multiplied as well.
I have two Orphek PR-156W LED light fixtures on a daylight, moonlight cycle of 12 hours daylight, 8 hours moonlight, four hours total darkness. While the display is in moonlight/dark, the refugium T5's are on. I feed everyone a daily cocktail that varies including frozen Mysis Shrimp, Brine Shrimp, Hikari Blood Worms, Rotifers, Phytoplankton, Oyster Feast, etc. except the RBTA which I feed 2-3 times per week with baby clams or raw shrimp. I soak all my food with Selcon, and I recently ordered Vita-Chem and will be including that in my foods as well. I target feed the polyps on my Sun Corals daily. Even thought my parameters are great and my water is clear thanks to the carbon, skimmer, pods, filter feeders and Chaeto, I'm starting to get quite a bit of algae growing on my live rock and equipment, so I'm planning to add a small Zebrasoma tang to a quarantine tank once it's cycled then to the display after 4 weeks to take care of this.
I wrote a book as I want you to have all the information in case I need to destroy these hitchhikers so you can tell me the best plan of attack. I saw the preferred recommendations include injecting vinegar, Joe's juice, buying a Nudibranch that only eats anemones (but I have a RBTA) and Red Sea Aiptasia X.
<The last is my current fave>
I don't want to upset my well balanced setup.
<Mmm, perhaps better/best to just wait then... as you state, the Glass Anemones don't appear to be mal-affecting anything>
Thank You as always for your dedication, passion and information sharing.
<Welcome! Bob Fenner>

Re: re: Can you ID these hitchhikers growing on my clam shell please? 1/26/12
Thanks Bob,
Do these anemones pose any threat being on my clam like that?
<Can; yes>
I've heard stories that they are ok at first, then become aggressive as they get bigger. I read the reviews on Marine Depot regarding the Red Sea Aiptasia X. Most are positive, but a few say that the Aiptasia came back in droves. Have you found this to be true in your experience?
<... see WWM re>
Also, will this product harm my clam or RBTA at all?
<Could; yes, but not likely if treated in situ>
Thanks for getting back to me so quickly and for all your help both on your site and in questions. You are a very valuable resource and have helped me an avid reefer. L
<Ah good. BobF>

Clam, hlth. 11/27/11
Hey Wet Web Media Crew!
Wanna thank you all for your time, effort and patience, providing everyone with all this information. Basically my question is, there seems to be some sort of bubble growing underneath my clam should i be worried about this?
<Mmm, yes... Involvements with the byssus can be dire/deadly>
I believe the clam is a T. squamosa,
<I agree>
about 3 inches long, a friend had it in his tank for roughly 3 months, i was actually with him when he bought it, but apparently has grown out of his tank (he has a nano) so i am the proud new owner of this clam.
Parameters, although I'm not sure are needed for this are:
Amm - 0
Ni - 0
Na - undetectable with api test kit
Phosphates - 0.00 with a Hanna checker
<Mmm, Tridacnids, all photosynthates, need some, measurable Nitrate and Phosphate...>
(is this possible? i test my q/t tank with it as well and it shows around 0.3 phos, so i guess it is working properly but there is still algae growth in my sump so there must be phosphates still right?)
<Yes and yes; though the algae may well be absorbing most all soluble>
Ca - 480
Alk - 3meq/l
sa 1.025
mg - 1600 - should i try to lower this?
<Mmm, t'were it me, mine, I'd lower both Ca and Mg, but if you're leaving, causing the Calcium to be this high, I'd leave the Mg where it is>
ph - 8.1
temp - 77/78
Anyway, attached are a couple pics of the clam with the bubble it is on the right side corner closest to the sps coral, my first thought was some sort of vermetid snail, but now I'm thinking it might be coming from the foot of the clam. Clam does not look stressed in anyway, reacts normal when it is shaded, as in retreats into the shell and i don't see any sort of gapping. If a better pic is needed let me know, this is from my iPhone, but i can get my hands on a digital SLR.
Thanks for your time,
<Let's start w/ obvious questions. Is this Clam placed on a piece of rock under the sand here? It appears to be too deep... What is the PAR value where it's placed? What do you feed it, the tank period?
DO read here:
and the linked files at bottom. Bob Fenner>

Re: Clam, Tridacnid, hlth. 11/28/11
So I read over the article, it has stated that T squamosa should have rock underneath to attach the foot, as you were probably going to suggest. Should I do this?
I am assuming the clam has already attached its foot to the glass at the bottom of the tank, would removing it do more harm than good?
<Use a new single-edged razor blade...>
If not, what would be a good way to remove the clam so I can put it on top of rocks?
Par value and lighting - I do not have equipment to determine Par values,
<Look to borrow from a shop (LFS) or a hobby club, fellow reefer>
but I think my lighting is more than sufficient, although it is at the bottom of the tank, it is a very shallow aquarium, only 14 " in height, and after overflow and roughly an inch of sand we are looking at closer to 11/12 " of water. I run a 250 watt Metal Halide, the bulb itself is a double ended phoenix 14,000K,
<Too high a temp. See the piece/article by myself and Calfo, linked where you were previously referred>
along with one of those new LED Kessil 150A 15,000 K (which I have been more than impressed with). Both hanging roughly a foot away from the water. Bulb on the halide would be 5 months old, and I change the bulb every 6-7 months.
Feeding the tank - I do not generally feed the tank much, basically once a week for the past month I have been feeding reef roids 1 teaspoon in about 120 gallons of water, I haven't noticed much difference and I might just stop it all together. I do however feed live Tisbe and Tigger pods, once a week each, I have a mandarin dragonet so I will not stop. However I will start to cultivate my own pods to cut costs, and after reading how easy it is on your site it would be stupid not to. Finally for the fish it is once a day either New Life Spectrum Flakes or sinking pellets, and once a week frozen Mysis.
Right now I am assuming the best course of action would be moving the clam, and placing it on top of some rock/rubble so it can attach the foot.
If this would cause to <too> much stress, please advise as I would suspect the foot has already attached to the glass and I can only see that the removal of the clam would cause the foot to tear.
Again, thanks for your time and help
- G
<Keep reading. B>

Stylochus matatasi Flatworm... Clam et al. eater 11/16/11
Hello WWM,
By perusing your site, I have determined that we had & may still have one or more of the Tridacna-eating flatworms in our tank.
<No fun>
I lost 2 clams in July, but also many snails. Then in August, I caught a HUGE flatworm. Grey-Brown, mottled. I figured it ate the snails but did not ID the thing at the time or else I would have realized it ate the clams too. We caught this thing and took it out but it broke into pieces. I tried to pick up all the pieces (at night, in my pajamas, holding a flashlight) but one may have escaped.
<Best to siphon out>
Forward to October. I still have 3 clams left. Start seeing dead snails again. Then another clam dies. Two weeks later, another clam, and two weeks after that, my last clam (this past weekend). All 5 clam deaths in hindsight match exactly the MO of what happened to other people's clams known to be eaten by a flatworm (by my research).
<Did you treat this system w/ an Anthelminthic... an anti-worm agent to rid it of this Polyclad?>
Took the last clam out and guess what crawled from his shell? A flatworm. This time I ID'd it, it is the clam eater.
I used flatworm medicine and did WC...but I think the medicine is really for planarians.
<Should work on/for all Platyhelminths...>
Will it kill the worm(s) I have?
<What is the active ingredient? Read here: http://wetwebmedia.com/fltwmchemcont.htm
and here: http://wetwebmedia.com/fshwrmidcuref.htm>
And how many do you think I could possibly have? Will I ever be able to keep clams again?
<Should be>
Thank you in advance for your response!
<And you for sharing. Bob Fenner>

Possible dying clam 8/26/11
I noticed this morning that my clam has not opened.
<<What type of Clam? Am going to assume for the purposes of this response that it's a Tridacnid'¦but in the future please be specific with the species if possible.>>
I can see just a small portion of the mantels inside the shell.
<<Is the mantle still on the brim or outer edges of the shell or has it begun to wane or recede to the point where you can clearly see the smooth lining of the inner shell?>>
I've had this clam for about 3 years (not sure of its age when purchased - and don't really know their longevity in captivity).
<<Again it depends on species, some fare much better in captivity than others but three years seems relatively short. Many aquarists and public institutions have Tridacnids that are decades old. Current data suggests they do not perish simply do to age (giving them a great potential life span) if they do perish it's usually due to something environmental, disease or predation'¦the latter of which most captive Tridacnids don't have to deal with if purchased responsibly. There are reports of large T. Gigas surpassing the century mark.>>
Should I give it a few days or remove it ASAP - I don't want to pollute the
tank. It's a 125 display with 30g refugium. Water param.s are fine (ALK=11;
CA=440; Phos=0; pH=8.3).
<<The parameters look good, though keep an eye on your alkalinity as your 440 calcium ppm has a direct correlation with this, the more dissolved calcium carbonate in the system the more difficult it will be to maintain a stable balance of alkalinity, though if you're using a reactor it likely is handling this ratio for you. As for the clam, without more detail (or even better yet a picture) it is difficult to diagnose the problem. >>
Would appreciate your advice.
<<You are correct in your worry that a deceased Tridacnid can fowl up a system and it is best to watch for early warning signs and remove it before it begins to decay in your system. I had to make a similar tough call recently at a public aquarium I volunteer at with one of our mid-sized T. Gigas, and eventually came to the unfortunate conclusion that the animals chance of recovery was so low it wasn't worth the risk of leaving it in the system to die and create organic carbon issues. For checking out your clam I recommend a few of our articles (but still would be more than happy to help you in the decision making if you provided more details or a picture like I mentioned above'¦and some more details about the tank as well; other inhabitants, lighting, placement of clam, species of clam.) If you start to witness animals in your tank that don't readily/normally display a diet for healthy Tridacnids start to snack on this clam (such as smaller fish and certain ornamental shrimp) this means that they sense it is on it's last legs and are not attacking so much as they are trying to recover the remains, if you notice this, it's a good indicator that it's time to remove the clam if the system isn't large enough to handle the decay.>>
<<More reading
And this last one if you need assistance in id'ing your clam
<<To you as well.>>
<<Adam J.>>
Re Possible dying clam 8/29/11

Hello Adam,
<<Welcome back Gene.>>
Thank you for your response. My apology for not identifying the clam.
<<No worries, it's just important to know the specifics so we/I can further advise you.>>
It was a Crocea. Notice, I said 'was'. I decided to check the stability of the clam knowing that if the foot was still well grounded on the rock, it was likely still alive. As it turned out, it was not. I removed it today.
<<Probably the best decision for the overall health of the system.>>
What seems odd to me is the swiftness with which it died. I saw no signs of distress until this morning. I do run a CR and rechecked my param.s after writing you. CA is actually very high at 560 and KH is at 12. I recalibrated the pH probe and found pH at 8.07 not 8.3.
<<These environmental parameters would be my main guess, Calcium carbonate levels are too high and affecting alkalinity and clearly your pH. T. crocea is more sensitive than other Tridacnid species and when things go bad for clams, they go bad quick..>>
Other corals seem fine and the fish show no signs of distress at this time.
<<They are more resistant but given time will show issues as well.>>
Of course, there could be other param.s that I can't measure that may be in play here.
Again, my thanks for your informative reply.
<<Anytime...something else for you to read as well http://www.wetwebmedia.com/calcalkmar.htm
http://www.wetwebmedia.com/marphalk.htm >>

Crocea Clam Issues/Tridacna Systems/Health 3/31/2011
Hey folks,
I have a question about my crocea clam who has been in my tank for over a year now. As you can see in the picture, there are spots (circled in red) on the mantle which appear bleached. It has not always had these spots, though I can't really pinpoint when they developed. In addition there on one side of the shell there is an organism (circled in yellow) which is a sort of transparent black color. You can see there are a number of siphons coming off this thing. Is this an actinian?
<No, appears to be a tunicate colony. An actinian is a sea anemone in the order of Actinaria.>
Its been there for at least 6 months. I tried cleaning it off with a toothbrush when I first noticed it, but I probably didn't get it all because it came right back. Neither issue seems to bother the clam very much in an obvious way. You can see from the second pic, there continues to be steady and constant growth. The photo was taken first thing in the morning after actinics came on, but before metal halide.
This particular reef tank is 65g with a 29g sump/fuge. It is about two years old. Houses a mix of sps and lps corals and very few fish (2 ocellaris, a Pseudochromis porphyreus and a yellow watchman goby) . There's a clean up crew and lately we've had a population explosion of snails and feather dusters. It sits about 8 inches under a single 250w hqi MH at 10K, supplemented by 4 39w T5s. Right now I've got Wave Point Coral Wave bulbs in there (very pink). <??> The clam itself is just over a foot beneath the light source. This is a pretty low nutrient tank so basic chemistry is consistently at 0 including nitrates and phosphate. Daytime pH is 8.5, night time 8.1, dKH is 8. I have not tested calcium recently because the only thing that gets dosed regularly is Kalk from top off water that runs through a Kalk stirrer. The tank is fed pretty heavily once a day and sometimes twice with a variety of foods including rod's food, oyster feast, some pellet and Nori.
The tank is basically thriving and the clam seems to be doing so too. I just want to make sure these two issues are not of long term concern but if so, what is your opinion on the action to take. Also, will those bleached spots ever fill back in?
<I believe you problem lies in the sterility of your system. Tridacna actually prefer and use nitrates in the water. Suggest you read here and articles/FAQs found at the foot of the article.
And here.
Thanks in advance!
<You're welcome. James (Salty Dog)>

Maxima clam doing very bed/ dying 1/12/11
Hi crew
My problem is the clam.
My system is 60 g hex, 154 w of t5 HO light fixture is 3" from the water (2 marine Glo and 4 power Glo), 80 lb LR, 20 lb LS, Fluval 4, remora hang-on AquaC, uv sterilizer 9w, chiller, Aqualizer,
<The magnets?>
2-koralia2 powerhead, 1- koralia1 Power head , 1- polario 15 ml wave maker,
Water condition: salt 1024,
<A smite low>
temp 77, nitrate 10, ammonia 0, phosphate 0,
<Umm, here's at least one fatal error. HPO4 is an essential nutrient for Tridacnids...>
nitrite 0, calcium 470,
<High... what is your Mg?>
iodine 0.03, ph 8.2, kH 100
Stocked with 1- blue hippo, 1 -yellow tang, 3- yellowtail damsel, 1- four and 1- three-stripe damsels, 1- maroon clownfish, 1- Dottyback bicolor plus some crabs and snails
Corals: green Sinularia, Candycane, torch , Galaxea, sun polyp, maze coral, brain coral Favites, mushrooms, Zoanthids, red Blastomussa, Echinophyllia, spider sponge and blue Tridacna maxima clam.
I bought the 6 inch clam 3 months ago placed it on the rock work about 7" from the surface of the water. The clam always showed its mantel with nice colors but never opened fully. About two weeks ago a flame angel started picking at it and the clam retracted the its mantel and stayed closed, slowly trying to open but the angel would bite it and he would hide again.
After about 6 days of abuse (week ago) I was able to remove the angel and take it back to the Store. The clam looked better right away until two days ago it shrunk into its shell and its not moving. The shell is slightly open about 3/8 gap, I can see inside it and observe a nice color but it's not responding.
I have looked on the WWM and internet for information on this dilemma with out a any result. I feel my clam has little time left if it's not already gone. Please respond as soon as you can. I have attached a picture of the clam as it looks right now. Thank You
<Mmm, I'd remove whatever chemical filtrant/s you're employing... perhaps feed this animal directly. Bob Fenner>

Re: Maxima clam doing very bed/ dying 1/13/11
Dear Mr. Fenner
Thank You so much for such a prompt response.
<Welcome Pawel>
Mg is 1200. Looking at my log HPO4 has always been low, too low (0 - .01),
<Ahh! Needs to be addressed. The chemoautotrophic algae in the Clam require this absolutely>
calcium always too high (450 - 500) only recently (1 month) I was able to get it lower and stable at 450.
<Again... this must be balanced/ratio with Magnesium concentration, and alkalinity:
scroll down to the pH, Alk... tray and read>
The clam still looks the same and not moving, it's been three days like that. I tried feeding it last night with no response . What should I look for as signs of death?
<...? Please read: http://wetwebmedia.com/TridacDisF6.htm
and the linked FAQs files in the series above>
Thank You So much for Your help.
<Welcome. BobF>

Derasa Clam gaping? 3/22/10
To Bob and all who have helped me so much before,
First things first:
Nitrates: 0
<Need some>
Nitrites: 0
Ammonia: 0
pH: 8.2
Gravity: 1.024
Salinity: 33
Calcium: 400+
<Magnesium concentration? Needs to be proportional...>
So, after researching (on WWM, of course), and reading "Got Tridacna", I learned that I could house a Derasa Clam under my 260 watts of CF lighting in my 55 gal reef tank. My local LFS had two of them for $89 each (if you
were to be a member of their "fish club") and I purchased one. I drip acclimated him for about an hour and a half, my LFS's pH and salinity were very close to mine. After I had placed him about halfway up in the tank, 12" from the light, I was observing him and noticed he was "gaping" a little bit and I'm not sure if he was doing this at the LFS or not. I went straight back to WWM and found that his mantle shouldn't appear this way either. I trusted my LFS with the thought in mind that I could return him within 48 hours.
<I would return this specimen>
So, what I'm asking is based on the attached pictures, is this guy going to make it? Or, should I return him and make a "healthier" investment?
<I would, yes>
Thank you so much for all that you do for not the hobbyists, but the animals we are trying to keep as pets!
Paul in snowy Chicago
<BobF in sunny S. Cal.>

Re: Derasa Clam gaping? -- 03/23/10
Hey Bob,
Thanks for the timely response!
<Welcome Paul>
Since the first day that I got the clam, he's stopped the "gaping" and actually seems pretty healthy. He opens for the daytime and closes up at night, and when my fish cast a shadow over him, he responds. Was there anything in the photos that may have led you to believe that he might not be healthy?
<Mmm, no>
Or was it just the issue of gaping?
Thanks again,

Please Help/Tridacna Clam Health/Predators 3/18/10
You could not get rid of me for long,,, maybe a new thread.
<Hello Craig, and yes this will be a new thread.>
This morning I noticed two pyramid snails on my squamosa. I have a sad face right now. After removing the clam I found about 10 more underneath. Now I have a really sad face. Scrubbed all of them off and returned. After inspection of the disgaured <discarded> water I could also see three of what I could only describe as a really small round flat clear worm, about the size of a pencil lead?????
<No idea here without a pic. Bob and/or crew may input here.>
Any way back to the devil snails, I am in trouble aren't I?
<Not yet.>
I also have a big derasa about 5" or so and could not find any on him, he is attached to a old clam shell so I dont know if this helps these snails from getting underneath. Both clams are on substrate.
<Are you sure these are Pyramid Snails? Pyramid Snails are generally white in color, have a slender shell that tapers to a point, and do not grow larger than a few millimeters. The Pyramid Snails use their long proboscis, which is a tube-like mouth, to puncture the mantle of a Tridacna Clam in order to feed upon the fluids and zooxanthellae cells. A few of these snails will typically not pose a threat to a healthy Tridacna Clam. If not controlled/eliminated, the snails can reproduce every 90-120 days, and if left to multiply, can cause serious harm or even death to the clam in a very short period of time.
If the infected clam has poor expansion and loss of color within the mantle, it may be too late to help it. Pyramid Snails feed mostly during the nighttime hours, and during the daytime, they will remain either at the base of the clam, or on the folds of the shell where they are difficult to spot. It is best to inspect with a flashlight a few hours after the lights have turned off on your aquarium. The snails will line up at the top of the shell just below the clam's mantle.
As you mentioned, it is best to remove the clam to a separate container of aquarium water where you can physically remove the adult snails, and brush the entire shell with a new toothbrush in order to remove any eggs.
I would do this weekly until no sign of the snails exist.
I will add that natural predators of Pyramid snails include several species of wrasse within the genus of Halichoeres and Pseudocheilinus. A few of the more popular species that are reportedly very efficient at controlling these snails are the Six and Eight Lined Wrasse (P. hexataenia and P. octotaenia), and the Green Wrasse (H. chloropterus). Hoping this helps remove your sad face. James (Salty Dog)>
Re Please Help/Tridacna Clam Health/Predators 3/18/10-3/19/10

Thanks again, after getting home about 7 est the Squamosa, believe it or not is the fullest and most beautiful I think I have ever seen. I do not know if this is because he may had been bothered for some time by these pests? and now there gone he is happy again? I do believe they are pyramid snails by pics and also where I first spotted the 2-3 up by it's mantle.
I forgot to tell you that I lost a maxima 2-3" about a week ago, but for some reason he never really seemed happy in my tank, so I did not check to see if it was a snail problem, and forgot to mention it. Have these guys always been in my tank?
<Likely came in with one of the clams.>
I have had the maxima, now dead about 3-4 months, the derasa about the same and squamosa around 2.Also when I cleaned squamy I notice a slimy layer of ??? which after doing some research sounded like what their egg masses are like. Do they only lay eggs on host?
I have never seen them on the clam after 1-2 hours of lights being off only this morning about 3 hours before lights are to come on, and two days ago my led moon light went out so now tank is in complete darkness, could this excel the problem? Meaning they did not come out of hiding because of the moon lights being on at night.
<Unlikely, there are full moons over the reefs.>
As far as the six line, I have a mc coskers <McCosker's> now are they compatible?
<Compatible with whom, or do you mean will the McCosker's Wrasse eat the snails? If so, I haven't heard any reports of this wrasse eating pyramid snails.>
and I read they may not get rid of them because of their sleeping habits at night time when the snails attack.
<The snails can/will also burrow into the sand bed near the clam and is where the wrasses will find them.>
Are clams their only food source?
<Likely so, but not 100% positive. Bob or another crew member may input here.>
Meaning in worst case if all clams die, I would just have to wait out their reproduction cycle to introduce clams again?
<If your clams are healthy now, there is no reason they should die from pyramid snails as long as you remove the snails and scrub off egg sacs as you have been doing. Eventually, you
should eradicate them completely and I would suggest getting a Six Line Wrasse to help you out.>
As far as the worms, To <too> small to take a pic, after a close look, looked like a round clear stingray no tail, instead of two eyes looked like a brown dot. One more why don't they go after my nice juicy derasa? Is the shell he is attached to help in any way?
<Possibly, depending on the clams location. Most folks that have Pyramid Snail outbreaks will temporarily place their clams on live rock once they are cleaned of the snails and eggs to prevent re-infection. Pyramid Snails do not generally leave the sand bed for higher ground other than feeding on a Tridacna.>
thank you, I will talk to you soon, have a great eveing <evening>. I am off to kill these little ba%%((e((reds.
<That's the spirit, and can I please ask you to run future queries through a spell checker? Will save me much time if I do not have to edit/correct before posting on the dailies.
Thank you. James (Salty Dog)>
Re Please Help/Tridacna Clam Health/Predators 3/18/10-3/19/10-3/22/10

I am sorry, since my accident, I need help with a lot of things.
<Sorry to hear this, Craig. James (Salty Dog)>

Derasa clam, hlth., paucity of facts 3/1/10
Hello WWM, love the site. I can spend hours reading all the replies. One question I am concerned about my clam, it has some curled in mantel, I ordered him from a wholesale supplier and it looks to be wild caught.
Anyways to the point is this a sign of pinched clam?
<Is it this way all the time?>
Here is a attached picture. He/She looks like it has been nipped by a few fish.
<Yes... what else is present here livestock wise?>
I have had him in for a week
<Oh, may be "just new" to your conditions, system>
seems to open fine every mourning and close at night. I suppose the all important tank stats are as follows nitrate=<10 nitrite and ammonia=0 ph=8.4 calcium is 460.
<A bit high... how do you adjust this? And very importantly, what is your Magnesium concentration and Alkalinity? Please see WWM re these important measures, co-factors>
This is an a 30 tall
<Not very large... inherent issues, instability...>
with 4 t5 ho and 175 MH I change 3 gallons of water every Sunday with Seachem reefsalt. the only thing I supplement is marine snow twice a week.
<Mmm, almost worthless. I would not use this product. Non-nutritive. But... what else do you feed the clam/system? Has this system been set-up long, have an established good-sized refugium?>
Thanks for the help
<Need much more useful information to aid your efforts. Do read through the articles, FAQs files archived on Tridacnids on WWM:
Bob Fenner>

Crocea Suicide Attempt... Tridacnid placement f' -- 02/08/10
Hello folks,
<<Greetings Lanny>>
I just awoke this morning and checked my 30g/150w MH/54w T-5 that is in my bedroom. To my dismay, my Crocea had hurled itself off the rockwork and smack on top of some pesky Actinodiscus.
I am not so much worried about the sting as I am about the strange bundle still attached to his rock.
<<Mmm, yes'¦damage to the byssus gland can prove fatal>>
At first I thought it was the byssus gland, but as I read, it seems more likely the byssus fibers.
She seems alright...the foot looks unscathed and the mantle is expanding. I have included a pic of the bundle - my apologies for the amateur photography. Am I correct in my assumption that is it merely the fibers and not something worse?
<<From the pic it appears to be more than just 'threads''¦but if the 'clam initiated the move,' as opposed to being 'knocked off' the rock, then it is likely fine'¦though only time will tell. And as it should be obvious, the clam was not happy in its previous location. I think it unlikely this species was receiving too much light here, so do look for other reasons for its wanting to move (encroachment from corals/other stinging organism, too much/too heavy water flow, etc.)>>
Thanks for the help and all your great resources.
<<A collective effort'¦you're quite welcome>>
<<Cheers'¦ EricR>>

Re: Crocea Suicide Attempt... -- 02/09/10
Thanks for the quick response.
<<Quite welcome>>
The clam is in fact looking great today. The mantle is fully extended, and the portion that was touching the Discosomas looks unscathed.
The clam was contacting a Montipora capricornis in its original spot, but they had grown into one another maybe three months ago. Could that be the irritant?
The mantle would rest on the Monti when it was extended. I have never had trouble with Acroporids irritating my clams in the past so I thought nothing of it. This clam actually used to reside nestled into an Acropora colony with no evident nettling.
<<Though some have stated that these clams (Tridacnids) are very 'tolerant' of contact with other cnidarians, I have to think there is a 'limitation' to that contact'¦perhaps variable among the differing species and even among different specimens>>
I also wanted to inquire if the scutes that were broken in the fall have the potential to harm the mantle.
<<Sure'¦if jagged/sharp enough>>
They are sort of jagged. I hate to sound like a mother with a newborn, but I worry about all my critters.
<<There's likely little reason to worry, but if these breaks are overly sharp/pointy, you could remove the clam from the water (make sure it hasn't reattached to the substrate first) and try to file them down a bit with a 'fine cut' metal file'¦or better yet, one of those small fine 'diamond-grit' files used to sharpen carbide router bits and the like>>
I see too much slaughter working in the aquarium industry here in So Cal. Last week I saw a 6' black-tipped reef shark crammed into a tank at All Seas and it cut deep.
<<Sad indeed>>
Thanks again for the help.
<<Is my pleasure'¦ Eric Russell>>
R2: Crocea Suicide Attempt... -- 02/16/10

Hello again,
<<Hi Lanny>>
Just thought I would give you the update on the Crocea.
It has been about a week now, and my clam is doing great.
After the jump, I placed the damaged clam on a piece of Montipora skeleton (another falling incident...Monti cap onto Fungia.--Monti lost...bad) and put it on the sand, front and center. I could actually see clear through from the incurring siphon through the foot and out the other side, and I was a bit worried. The mantle never stopped extending fully, and it even has repaired some nicks in the scutes.
<<A good sign>>
While shifting things around to accommodate a couple new frags, I gingerly moved the Crocea to find that it had already repaired itself enough to attach to the base!
<<Very encouraging indeed!>>
Thanks again for the help.
<<I'm pleased to hear the clam is doing so well my friend'¦ Cheers, EricR>>

05/02/10 Clam and Hammer Coral comp.
<Hi Megan>
I introduced a hammer coral into my reef tank last week. Coral doing great, but my maxima seems bothered now.
He has gone from upright on his perch to leaning sideways as of this AM...the side closest to hammer coral is what he is trying to move farther away.
<I see>
It's not as if he is right next to coral...hammer is at bottom, he is at top on rocks...at least 8-10 inches of space between them....but he definitely seems irritated...could the hammer's chemicals flowing thru the water be upsetting him?
<Yes, and this coral has been reported to have very long sweeper tentacles>
Can I wait until tomorrow to take the coral back to LFS?
<Probably yes, but is the Clam 'downstream' of the Euphyllia? If so, then switching these so that the sweepers are pushed in the other direction might do the trick>
If I have to choose, I choose the clam!!
<Move one of these and observe>
Finally, what corals will not bother my clam? I have Zoanthid, Mushroom, Star Polyps, etc. but wanted something a little more advanced.
<Mmm, try something like a Montipora, an excellent, non-aggressive intermediate coral, that is usually ok with what you have listed>
I did read up on this stuff, I do ask lots of questions...but these spur of the moment situations sometimes throw me for a loop...thanks for your time!!
<No problem Megan>

Amphipods Irritating Maxima clam? 12/7/09
I am having some concerns over one of my maxima clams not opening completely. At first I thought it could be pinched mantle. I have researched this and don't find a whole lot out there on the subject.
<Oh! Barry Neigut just had our online 'zine run his definitive piece on this ailment:
I am also hesitant to do the prescribed freshwater dip which could possibly kill an already stressed clam. Especially since I am uncertain this is what it could be. When the lights are out in my tank I searched with a flashlight and noticed amphipods all over the outside of its shell. Attached is a picture pointing a few out.
<Well done!>
Placement is in the base rocks in sand. I believe they are amphipods after searching this site and many other
<Do appear to me as thus>
I am wondering if they are irritating the clam causing it not to extend its mantle fully.
<Could well be>
I also notice a few crawling about during the day which leads me to believe this could possibly be the case. I have
another maxima which looked very good for a while now showing the same signs. Amphipods are all over this shell as well. I have a crocea clam the amphipods don't seem to bother which looks great. Maybe moving the maximas
higher up away from the sand would solve the problem?
<Mmm, doubtful... I would...>
Also nothing else in the tank seems to bother the clams (2 true percula clowns, hippo tang, Kole
tang, Banggai cardinal, 2 cleaner shrimp)
My calcium is 380 (working to get this to at least 400). Alkalinity is 11dKh. Magnesium is 1200 ppm. pH is 8.2. Any insight would be great.
Thanks in advance.
<I would seek either to bait/trap them out (meaty food wrapped in some filter media, stuffed in a plastic pipe... at night) removed after an hour or two), or look to "renting" a relatively, most likely non-Tridacnid-predator that will hunt down, eat these. The list is long here; I would sort through a search on the Net in general. Bob Fenner>

Re: Amphipods Irritating Maxima clam? 12/16/2009
Dear Mr. Fenner,
Wanted to thank you for your help with my Maxima. I removed the clam from the sand to move higher in the rock work. I decided, while it was detached, to give a freshwater dip knowing after I placed it in the rocks it could be challenging to remove if necessary. As soon as the clam was placed in the dip water the amphipods on the clam fell off.
<But fast>
There were quite a few more than I had actually thought. After 20 minutes I returned it to the top 1/3 of the tank and am happy to report the clam looks 100% better. It has attached, has been wide open and has been for about a week. Thanks again for your help.
<Ahh! Congratulations on your success, and thank you for your report here.

Compatibility... Bivalves and Crabs... feast 11/29/09
<Hello Sony>
I had a weird issue, I had a maxima clam some smaller green clams a flame scallop and they all got eaten after in introduced some blue and red dwarf and zebra crabs, along with some Nassarius and margarita snails . could
any of these have eaten all my clams. who and why? and does this mean I cant ever add clams because I wont be able to find the culprits and round them all up?
<Very little info for me to base an informative reply on. I would like to know your tank size, water parameters, lighting make-up, and what types of fish and other invertebrates, if any, are in the system.
James (Salty Dog)>
Sony M. Onatte
Re Compatibility, Take 2, now reef... env. issues -- 12/01/09

I have a 30 gal long with roughly 45 - 50 lbs of live rock. water levels all normal.. 0 nitrate nitrite and ammonia. salinity 19-22.
<1.019-1.022? This should be much closer to 1.026...>
If everything is 0 do I still have to do water changes cuz I'm topping off water 3x a week cuz it evaporates so fast.
<Short answer: yes. Long answer -- the fresh water you are adding back 3x a week is not equivalent to a water change -- this is only replacing the evaporated system water. No export of nutrients has occurred. Water changes achieve 2 goals: nutrient export from the tank, and replenishment of ionic balance within the water. These two things are indispensable, and cannot be substituted by any filter, additive, or otherwise.>
My lighting system is a Current USA power compact with Dual Daylight Lamp (6700K & 10,000K), 1 Dual Actinic Lamp (420nm/460nm) and 3 Lunar Lights.
<Not nearly enough intensity for clams -- Power Compacts simply don't have the depth of punch that T5 or Metal Halide offer.>
<I> have an <A>qua <C> <R>emora skimmer<,> <I> have a black clown<,> a reg<ular> clown<,> a domino, 1 chromis, 2 Fiji blue and yellow devil. 3 camel shrimp, 2 skunk shrimp, assorted margarita, turbo, and Nassarius snails. 3 emerald crabs, 25 assorted blue and red dwarf crabs. 5 diff types of Zoa's.
<Sounds nice -- a bit overstocked... but please, in the future do run your email through a spell check, practice proper punctuation and capitalize proper nouns... All is posted for posterity here, and these corrections
take time out of our day.>
2 bleached trumpet corals from 3 months ago because one of my pumps died while I wasn't home for a month. ( will their color ever come back or is there anything <I> can do about it)
<If they have not died yet, there is hope.>
an recently eaten maxima<,> assorted green clams<,> 2 flame scallops. <Flame scallops do not fare well in home aquaria -- and 'assorted green clams' gives us nothing to go on here..>
and PS: my Zoa's aren't growing as fast as they once were almost to a stop.
<Your salinity is far too low, your ionic balance is off -- fix this, your growth will increase.>
any magic food? I rarely target feed. hopefully this is good enough info.
thank you
<Should not need much/any direct feeding in an adequately equipped configuration, but would certainly benefit from a feeding of Cyclop-Eeze or other similar small foods.>
Sony M. Onatte
Re: Compatibility... Now ScottV rallies! 12/1/09

I just feel like the problem hasn't been addressed.
<It has by Justin below, water quality, stability and lighting are the culprits here, not the crabs.>
My maxima clam has been in my tank for over a year, the green iridescent small clams were newer but they were fine too until I added a clean up crew.
<Unfortunate coincidence.>
All the dwarf crabs I was talking about. Then the clams just started to clear out. No flesh left in the shell. I wanted to know if you have heard of this before?
<Yes, the crabs are scavengers, they will feed on dead or dying clams.>
And will I ever be able to have clams because of this?
<Sure, by addressing the issues listed below! <<Above now! RMF>> Scott V.>

Unhappy Clam?/Tridacna Health 9/9/09
Hey gang!
<Hello Carla>
Quick question, my t. crocea clam just detached itself from the rock it's been happily (or so it seemed) anchored to for over two years now. I had noticed the clam "rocking" itself on occasion, usually when stressed such as when the lights first come on in the afternoon (I'm on a reverse light cycle to help control temp. swings- the tank gets no natural light).
Otherwise seemed ok, good mantle extension, etc. Obviously it's unhappy about something though, or wouldn't have jumped ship like that! Didn't notice any byssal threads in the tank, attached to the clam, or the rock. I moved the clam back up to his perch on the rockwork, and redirected the powerhead that had been blowing behind that rockwork in case that was irritating him- his spot is also below the intake of the skimmer, but there are no discernible strong currents that I noticed when my hand was in the tank. Any other tips? Just keep an eye on 'em? It is just beginning to extend its mantle a bit- obviously clamped shut for a few minutes after moving it. I wonder if it is outgrowing the shelf/nook in the rockwork and was trying to find more room to grow? I have read that it's a good idea to leave the clam on the sand if they detach with a piece of rock below them in the sandbed to attach to, but this is a 29 gal. tank with PC lighting (60 watt 50/50, 60 watt 10000k?) so it needs a high placement in the tank.
<For sure.>
The bulbs are in need of replacement (a little over a year old, I believe)-
could the wavelength shift with aging bulbs be part of the problem?
<Possibly, as your lighting is close to borderline to start with. Anyway, wondering if you had
any feedback and I'll keep you posted on any new developments!
<I would replace the lamps and further observe. A link to a very informative clam article by James Fatherree, a regarded clam expert, will be good reading/learning for you. http://www.reefkeeping.com/issues/2007-10/jf/index.php
<You're welcome. James (Salty Dog)>
Re Unhappy Clam?/Tridacna Health 9/18/09

James and Crew,
Thanks for your advice!
<You're welcome.>
I moved the clam back to his original position in the rockwork, only to have him "jump ship" again by the next morning, so I perched him in a smaller piece of live rock that is a thickly encrusted shell of some kind, and has a nice hollow cup for him to sit in, where he seems quite happy and has attached, and is now at least 2" closer to the lights.
<Good, now leave it alone.>
When I turned this rock over to repurpose it for a clam perch, I discovered a tiny light-starved mushroom polyp growing on the underside (now the top)- this is growing next to the clam- will it irritate or injure the clam? If so, suggestions to relocate the polyp? Careful razor blade surgery? It's a quite smooth surface, so might work, and I'd obviously rather sacrifice the polyp than risk damage to the clam... but thought I'd leave the two for a bit to see if they can work things out, unless anyone has advice to the contrary... :-)
<Leave alone, not to worry until you need to.>
Several people have commented- "A piece of your clam fell off!", which of course led to minor panic on my part until I realized the were talking about the mushroom anemone, which has similar coloration to the clam, and is attached to the rock near the base of the clam. Funny...
I also discovered the root cause of clam distress- stupid stupid stupid me neglected to plug in the canister filter after cleaning it (don't do vital maintenance tasks when distracted by company next time, I suppose). Ack!
Opened it up, and man was that stinky- sent my fiancé© and his friend practically running out of the room. Discarded the media (except for the Chemi-pure, which I rinsed/soaked very very well- should this be discarded as well?
<Not if it is still functional. Water clarity will determine that. A good test to determine this is to put several stripes on a white paper with a yellow highlighter, then tape the paper on the side glass.
While looking at it from the opposite side glass, you should be able to see the yellow highlighting. If not, time to change the Chemi-Pure. I prefer to change the Chemi-Pure before this stage, say every three months with
an average stocked tank.>
Obviously has lost a lot of effectiveness, but it won't leach contaminants back into the water, correct?),
added carbon and floss to temporarily polish the tank (usually I just run Chemipure or sometimes PolyFilters as well, and mainly use the canister for increased water volume and circulation), and filled with new salt water, and within 24 hours everybody in the tank looked much happier- I'd wondered why the skimmer was suddenly producing double the usual amount of goop. Sigh... live and learn, I suppose... bad tank owner!
<No, just the learning curve being experienced.>
Question about a new addition- bought a serpent star on Tuesday (and a 4 # hunk of gorgeous cured live rock with a pretty polyp on it... no one believes me when I tell them the rock was more expensive by several times than the starfish.. heh), and he's still hiding out in the live rock cave he retreated into when I released him.
<Far more active at night.>
There was quite a difference in salinity from the store tanks (1.028 in the bag) and mine, which is around 1.023... working to bring that up slowly with water changes and topping up with light salt mix instead of fresh water. I drip-acclimated him for just over 6 hours (even though the LFS guy said that I didn't need to drip-acclimate- sounded crazy to me and contrary to everything I'd read... did it anyway)
<LFS is wrong here.>
to help even out the dramatic shift in salinity etc, but know that these animals are quite sensitive.
<Sensitive to sudden pH/salinity changes, correct.>
It's definitely alive, and looks healthy, but sluggish. Patience?
He was the most active guy in the store tank, climbing the walls with the lights on. I have my tank on a reverse-light cycle, and was hoping to watch his "nocturnal" scavenging activities... hopefully he just needs time to settle in and recover from the stress of acclimating to new tank conditions? Anything I can do to help him out?
<You are doing fine.>
Thanks for all the reassurance and advice that I've gotten from you guys over the years- what a great resource!
<You're welcome. James (Salty Dog)>

Clam with hitchhikers -- 09/08/09
I hope everyone is well at the WetWeb!
<I am for sure!>
I recently purchased a 2.5 inch Maxima clam, with 2 large, and 3 smaller clove polyps on its shell. One of the large ones is at the very top, and the mantle of the clam expands around it to open, the others are further
down the shell, (and obviously reproducing).
The Clam seems ok - it opens fully, but I don't know if I should be removing these polyps or if that would be a worse stress on the clam than leaving it alone. If so, how would you recommend (Exacto-knife was my best guess...)
Thanks as always,
<A sharp blade, yes... not likely chemically toxic or physically harmful however. Bob Fenner>

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