something killed and ate my maxima clam
 

bought a 2 inch maxima from one of lfs on weekend and the little guy opened up nicely within an hour after placing into tank. overnite something opened up this little guy and all that i've left of him is his wide gaping shell. the thing is i have 6 adult croceas and maximas in the same tank and nothing ever touches them not my mated pair cbs, cleaner shrimps, sally lightfoot or the couple emerald crabs. don't think the culprit might be any oversized bristle or fireworms since i've trapped most of them out. anyway if anyone is considering getting a smaller clam it might be a good idea to consider what's living in the tank first.

Crabs

If it died overnight after buying it and your others are doing fine I think it simply didn't handle the move very well. What did you do to acclimate it? A small dead clam will be consumed in a mature system very quickly. When I feed my fish mussels and clams from the grocery store they are bare well within a day even if the fish don't touch them.

dead clam
 

i drip acclimatized clam for almost 45 minutes even though i live 15 minutes from store and our water perameters are almost identical so i dont believe transport shocks caused its demise. i've also observed and lusted after these particular clams sitting pretty the last 3 weeks in store and so i was very sure they are quite healthy. still think something tore into it for an expensive meal.

I have seen higher mortality in smaller clams. Sometimes there is no reason for a clam to expire. Clams need time to reattach their foot to substrate, so I guess it is vunerable to attack at its base.

Take a good look for pyramid snales that make have come with him.....they could kill it that fast and all your clams are at risk now!

IMO it was potentially on its way out when you bought it. Clams are funny that way, they look completely fine even if they're sick and then overnight they're done. I find usually scavengers don't bother them unless there is already a problem (or you have some of those monster sized bristle worms that eat everything). Next time place a snail shell or something solid underneath the bottom of the clam for it to attach to and that way it won't be vulnerable to attack from below.

I agree with Christy. Also these little clams need fed phyto. They don't have enough surface area to be able to survive on lighting alone.

Clams usually look just fine, then they are suddenly dead. If it was in store for 3 weeks to a month it probably starved.

I bought 4 of these little guys a month ago when they hit all the stores. I feed them phyto every other day and they are really growing.

Same there, I think it just plain died. I would never ever buy 2" clam as they are way too young and fragile and they need feeding because their mantle is not yet big enough to give them all the energy they need.

It is best to get at least 4" clam as these do not require feeding.

I don't think your clam was killed because your other clams would have been killed way before that. That is almost the proof that your clam just died.