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FAQs about Giant Clam Disease, Pests & Predators 2

Related Articles: Tridacnid Health: Pinched Mantle Syndrome in Giant Clams by Dr. David Basti, Deborah Bouchard & Barry Neigut, 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 Disease 1, Tridacnid Disease 3, Tridacnid Health 4, Tridacnid Health 5, Tridacnid Disease 6, Tridacnid Disease 7, Tridacnid Disease 8, & 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 BusinessBivalves, Bivalves 2, Lighting Marine Invertebrates,


Maxima Clam Injury 2/28/05 My maxima clam was injured and now while open you can see its insides from about one third of his mouth as if its "sheath " was sliced open. He seems fine and closes and opens with the lighting etc. Can they repair themselves or is it just a hard luck situation? and also what could have done this crabs, shrimp, or tang could be the only suspects? Tank you for any info !!! Eric  <I am not clear on what exactly is wrong. All Tridacnid clams have two openings in their mantle. The excurrent siphon looks like a tiny elephant trunk and is small. The incurrent siphon is a large opening (usually about 1/4 of the length of the mantle), and the gills and other structures are often visible through it. It is possible for tears to occur in the mantle, but this is unusual in my experience. Usually if an animal is attacking a clam, it does little damage or extreme damage. Consider visiting www.clamsdirect.com There is a lot of info there on clams and their care. Best Regards. AdamC.>   

Ripped T. maxima Foot - What to do? Hey all, I was just weeding out Caulerpa today, and I got a long strand. I was pulling it out, and it was attached to my baby maxima clam. When I pulled it out, the clam came with it. His foot has been ripped clean off. There is a hole where his foot was, and some "hair" (byssal threads) were coming out of it. I don't know where his foot went. I glued him to a rock, and positioned him where he usually is. Never, never glue a clam in place because if he doesn't like it where he is, he can move. Some clams will move if they do not like the water movement or lighting. He is fully extended, with no gaping. I really love this clam (as some of you have come to know very well by now), and would hate to see him go. The no gaping/fully extended part gives me some hope. What do you guys think? Any advice on the subject? Thanks in advance! Mike 

Here are some pics...The hole is very clean. No ripped tissue, just a hole surrounded by tissue with byssal threads coming out of it. I think I may have found the foot...it was rubbery, and looked like fat Halimeda, it was covered with algae in most places, so it had a very dirty look. It was long, though, and looks nothing like the foot he had when I got him. The clam was upside down for the photo shoot, that is not how he normally is.  <Depending if the clams develops a bacteria infection and if this is the case it could start to down hill within a week or so. Barry Neigut - ClamsDirect.com >

Coral Banded Shrimp/Maxima Clam Injury Does a maxima clam ever appear ripped... open to expose the inner portion of itself?  <Yes>  My clam has me a bit perturbed. There is a rather large area that just doesn't seem right. The clam is about 1in. long and the tear is 1/3-1/4 in. in length. If this is a tear, you see it most when it is fully opened under the halides. I'm assuming it's ok... until he doesn't open up.  < Melissa, here is a link on clams you should read. http://www.wetwebmedia.com/tridacnidart.htm  Also my coral bandit dropped his arms off (both)... will they grow back?  <Either one or both will appear at his next molt. Both should be back within two molts. James (Salty Dog)> Thanks for your time. <You're welcome> 

Clam question Hello there- My father says WetWebMedia has given him lots of great advice- I have a question about Tridacnid clams (purple/blue (not maxima)......I've had a couple for about a year or so, and they both died the other day, both within about 24 hours.  All I could see was what looked like clear snot, and what looked like pieces of sand in the mucus, .....the clams closed up, and they seemed to have a hole in the bottom of them......the only thing that seemed to be near the clams, were brown tiger tail cucumbers. Have you seen this before? Thanks for your help..... DaveB <Hello Dave, Have you fed your clams weekly?  Marine Snow is a good product to use.<<Uhh, not in all's opinion here. This product is a placebo IMO... has VERY little nutritional value>>  It's not necessary to feed daily, a once a week feeding should be enough. <<Barry Neigut suggests a minimum of 3 times per week... and NOT Marine Snow>> Also, do you change your bulbs on a yearly basis?  Clams do require strong light of the proper spectrum.  Just cause the light lights doesn't mean the full spectrum is still there.  Most clams will only do well under metal halide lighting. James (Salty Dog)> 

Clam Question 1/5/05 <Dave, I have backed up to your original question> I have a question about Trinidad clams (purple/blue (not maxima)......I've had a couple for about a year or so, and they both died the other day, both within about 24 hours.  All I could see was what looked like clear snot, and what looked like pieces of sand in the mucus, .....the clams closed up, and they seemed to have a hole in the bottom of them......the only thing that seemed to be near the clams, were brown tiger tail cucumbers. Have you seen this before?  Thanks for your help..... DaveB <Anytime more than one similar animal dies at one time, it is suspicious for either poisoning, disease or predator.  Your clams were probably T. crocea.  They normally have a large hole a the base called the byssal opening.  It's symmetrical, tear-drop shaped with slightly irregular edges and looks natural and like it should be there.  If the hole you are talking about is small (BB size) and looks as though it was drilled, you have a boring predatory worm or snail.  There are also predatory worms that engulf clams and snails in a blob of mucous to suffocate them and then eats them.  All of these are extraordinarily rare to encounter, but it is possible and would fit with what you described.  Have you recently added any animals that such a critter could have hitchhiked in on?  Catching these beasts can be tricky... baiting them with snails and then watching at night to try and catch them is often necessary.   Best Regards.  AdamC.>
Re: clam question
Hi, thanks for getting back to me....yes, they are Trinidad Croceas....exactly.   <Hee hee! No Tridacnids in the Lower Antilles! Oh, AdamC is out visiting the west coast so am responding in his stead> What happened was exactly what you were talking about, a mucus that looked like they covered the clam, and suffocated them............ but at the same time, it looked like the base was worn away, not by a hole though really.   I added an abalone and a tiger cowry, but other than that all has been the same. I lost one of these about 6 months ago the same way.  I had 3 T. crocea, now just one Derasa left. Thanks, Dave <Please do read through our scant archives on giant clam health: http://www.wetwebmedia.com/tridacdisfaqs.htm and the Related FAQs (linked, in blue, at top) if you haven't already... and on to the references listed. Bob Fenner>


Crocea clam not opening - 12/6/04 Hi Crew!, Hoping someone may be able to help with one of my Croceas. <Sure hope I can help. Sorry for the delay, I was out of town and I thought I had to answer but it got away from me. I do apologize> I have two, both purchased at the same time 6 months or so ago. Both are a little larger than a clenched fist. They sit on very large clam shells (from the beach) <I don't recommend using beach collection in a personal reef collection but if you bleached it then.....> on the bottom of a 75g (corners) with 2 x175 MH and 2 x 96 pc. One has not been extending his mantle and stays almost closed most of the day. <Hmmmm> Some times it is extended a little but not to the extent that the other is. <weird> Param.s are: ph 8.2, Alk 3-4 meq/l, Ca 400. temp 80. Even though not fully extended it still reacts to light change (shadow) I do not know what to do for him. <I would leave him be. Be sure to watch for any pests that may be picking at the mantle. Don't always trust the tang. Also, be sure to try some of the commercial foods directed at clams, such as Reed Mariculture live Phytofeast or their coral and clam diet. Photosynthesis  alone, does not meet all nutritional needs of these animals > My tang does bother him at times but does the same to the other clam and that one could care less <Don't be so sure> Any ideas? <See the above> Thanks. <Hope I am not too late. Sorry for the delay. ~Paul>

Closed Clam Hi. <Hello> I have had a crocea clam for about 5 months now.  Everything has seemed fine with the clam until this morning when I noticed that the clam was not open when the lights were on.  The clam has seemed fine it would close immediately when a shadow went over it.  I just did a water change yesterday and I kept the salinity the same at 1.024.  The temp is at 79 degrees and the ph is fine.   All of my other corals are doing very good. In your experience why would a clam do such a thing? Any advice would be great. <Do you see any pyramid snails on the clams byssal gland? Bristol worms are also known to bother than clams byssal gland, causing it to retract its mantle. Do you know if there was any pH, temperature, or salinity swing during the water change? Do you see anything bothering the clam? Recently a T. squamosa of mine wasn't expanding its mantle fully. I was puzzled why the mantle was extending, due to the fact that nothing changed in my tank. I later found some shrimp picking at the mantle of the clam, possibly looking for some food. A simple feeding every several days completely solved the problem. I feel that any one of these which I described could cause the clam to close its mantle. Some more information about pH, salinity, and temperature would really help. As well, check the byssal gland of the clam for any worms or parasitic snails.> Thanks, <Take Care, Graham.> Tim Jones

Why are my clams losing color? Hi guys! I have 8 clams (left) only lost 2 in 5 years, 1 was only 1.5" the other I made the mistake of moving too many times. (7" Derasa) Have Maximas, Croceas and 1 Squamosa. (all are 3-5") They were in my 75 gal reef w/ 2-175 wt/10K MH & 1-130wt act. and doing well. I decided to make a small "clam tank" out of a 20 gal. tank that no longer had any residents, but has been set up for about 3 years. It is a very stable tank for a 20. 2.5" of fine sand, a bunch of Nassarius snails, Cerith snails, 4 Turbos, 6 Scarlet hermits, 2 small Rio's, a Prizm skimmer and now a 150 wt/20K HQI MH pendant about 6" from the surface. Most of the clams seem to be doing well except 2, a blue Pohnpei Maxima and one of the Croceas that's solid purple. They seem to be losing some of their color at the edges slowly. Some lost a little color in the 75 gal until I started adding a little Iron/Mang. supp. and then that seemed to help them regain the color. (even 1 that arrived a little bleached) The bleached tissue looks healthy except the pigment/Zoo is going away. I give the same supplementation variety as the big tank (proportionate) but I'm wondering if the smaller volume requires more or less of something. << Well here is where test kits are important.  You may have had something adding or removing the magnesium from your old tank.  The best thing to do, is to not worry about how much you are adding proportionally, but what the actual levels are. >> I used to use all SeaChem stuff but after having a problem keeping my alkalinity consistent (with the 2 part cal/carb) I started using Kent Liquid Reactor. It is so much easier to use and doesn't make the alkalinity go up and down. (switched months B4 moving the clams) Any ideas why the clams would lose their color in this situation. << I believe most clam color is due to lighting.  It is very difficult to replicate lighting from one tank to another.  I'm assuming you are using the same type of bulbs, and the clams are the same distance from the bulbs, but even with that it is tough to say. >> I don't think it is a light issue. Does the calcium level have any bearing on coloration? << Not as long as it is in that acceptable range (250-600). >> Is the Prizm too much skimmer for this little tank? There are 2 Gorgonians in there with them (Sea Whips-purple and red/yellow) and they are growing like crazy. << Well now this may be the case.  Clams do filter feed much.  So it is okay to skim heavy, as long as you are feeding them as well.  I don't like to advise people to turn down/off their skimmers, but this may not be a bad idea for you in this situation. >> I feed them all Liquid Life frozen plankton every other day or so, a little Iodine, the Iron/Mang. SeaChem liq. calcium and the liquid reactor twice a week. No, I haven't read Daniel's book yet but I'm going to order it now. Thanks for any help! Scott << I guess I would also say that an iodine and magnesium test kits wouldn't hurt. >> Scott Howe        <<  Blundell  >>

Dying Clam Hi, <Hi Ryan> I've just got back from work and, looking into my tank, found that one of my maxima clams is looking in a bit of a bad state.  His shell is wide open and he seems to have detached from it and has shrunk right back away from the opening.  All in all he looks pretty dead. <Such a shame but sounds like it.> I'm trying to convince myself that this might not be the case but I think I'm kidding myself really.  He's not moving at all (even when poked) and my four cleaner shrimps have moved in vulture style (it couldn't have been them could it???). I was at a complete loss until I started reading through your FAQs and came across something you said about supplements.  The thing is, a couple of Aiptasia anemones recently sprung up on his shell and I read somewhere that a good way to get rid of them is to inject them with supplements.  I dose iodine regularly for my soft corals so I decided to inject them with 0.5ml each of that.  Do you think this could have done for the clam? <Its possible and its also possible that some escaped and went right into the clam.> If not I'm not sure what it could be.  We did have a power cut this morning but it was only a couple of hours and there was no significant drop in temperature. My other maxima is fine.  There's no sign at all of predation.  There have been no recent changes in tank setup recently either. What do you think?  Any advice would be greatly appreciated - I'd hate for this to happen again. <The only thing I would make absolutely sure of is that your clam is getting enough to eat and make sure nothing is picking at him.> Many thanks,

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