species discussion: T. derasa

[Reefer4ever]

You mean at the bottom where they attach? How did that happen? You have any pictures?

[ErikH]

No idea how it happened, the clam was over a year old. I just noticed one day it was slumped over.

[Reefer4ever]

Did you have any big fish or crab that could have ripped at the base or hit the shell hard enough to break the seal on the bottom of the clam? That is very odd.

[CoryDude]

Clams are also susceptible to poor shipping. With all the things involved in the collection, holding, distribution, shipping, etc, it could have been overstressed and on it's way out before you even bought it.

I had a deresa clam who's shell grow to over 12". When the mantle was extended it, would take up over a 1/3 of the bottom of a 90 gallon tank. It develops a very pretty brown/blue/green spotted pattern along the edges of it's mantle. It was also the most tolerant of all the clams I've had experience with. Very good clam for a beginning aquarist. Here's a pic of mine about 2 years before it died:

[hobogato]

dylan, a couple of possibilities:

1. trapped air - if the clam was exposed to air and not burped when returned to water, an air bubble could have been trapped inside. this can cause any tridacnid clam to close up and die.

2. parasitic protozoan - Perkinsus olseni was a very common infection causing lots of clam deaths recently, especially in wild collected T. derasa clams from Vietnam.

another possibility is a parasitic flatworm - had one take out a few clams several years ago.

[hobogato]

that is a nice clam cory, i bet it was a real calcium hog!