Clam not doing well?

[ericgreg]

I have a 24-gal Aquapod with a 150 watt 14k Sunpod light. The light is fairly new so I have it on for only 6 hrs/day so as not to shock my stock. I recently added a derasa (sp?) clam. I put him on a pedastal in the tank fairly high up, and he has closed up after 3 days. At first, I thought that snails and other critters were crawling on him causing him to close. While that may be true, I am now wondering if it's something else. I have now moved him to the bottom of the tank where the light isn't so bright, but he so far still hasn't opened. I can see into his shell, and he still has his color about him. I feed the tank every other day with phytoplankton for the corals, and every few days with pellets for the fish. I get my water at the local lfs, and that is tested regularly - all good.
Any thoughts as to what's going on?

[crvz]

First, I'd ask for actual water measurements that you do yourself. Particularly ammonia, nitrite, nitrate, pH, temp, and salinity. Also, phytoplankton is not really benefiting anything in your tank other than increasing the nutrient levels in the setup; very few critters eat phytoplankton, and your clam surely doesnt need it.

I'd first look for pyramid snails on the foot of the clam. You did the right thing by moving it down, those are lower light sand dwelling clams, and being up high in the rocks was the wrong place for it. So check for parasites, and some pictures may help. Good luck!

[Wiskey]

I ecco what Chris said, another thing I'd ask is,.. What kind of fish do you have in your setup? Allot of fishes like to pick at the slime that coats the underside of the mantle of a clam and it will cause the clam to stay shut, eventually killing it.

While clams are one of the very few things we keep in our tanks that can eat phyto they most certianally don't need it,.. they get more than enough food from detritus in the tank, other foods we feed and light. I would also stop feeding the Phyto just for reasons of your water quality.

Whiskey

[Jared J]

I was just reading an article in the 2009 Marine Fish & Reef USA mag by Scott W. Michael, where he says that in aquarium settings it is beneficial to feed clams phyto because of their great metabolic needs. Also that the algae in the clams tissue only provide enough sugar if the clam is large enough, meaning clams 4 inches or larger with enough mantle volume.

DT's says that clams can feed off the nitrogen from detritus but for the protein, fats and other nutrients they need to feed off phyto.

Now I'm really confused.

[crvz]

Hmm, interesting input, Jared. The consensus now is that clams, of any size, don't need phyto. It used to be the everyone said small clams were doomed without phyto, so it's odd to see that a 2009 (? is that right?) article repeating an old tune.

[Jared J]

so it's odd to see that a 2009 (? is that right?) article repeating an old tune.

Well, it's this newest issue, says 2009 on it: