Damaged byssal gland - This is the structure that builds the threads clams use to anchor to the substrate. If the gland is damaged a clam will continue to live for a handful of months then either gap and die or close up and die. If you've had the clam for 6+ months and not forcibly moved it lately then this is unlikely.
Irritation - A CUC messing with the clam will keep it from opening. But once the irritation has stopped a healthy clam should open up within a few minutes. If the clam is on the sand bed you might consider moving it up onto the rocks. This will keep the snails away from it. And as for the hermits... I would just get rid of the them altogether. IMHO hermits have no place in a reef tank.
Parameters - Small clams especially maximas are delicate. The other corals/inverts in your system may not be as sensitive at the clam. I would suggest checking your alkalinity as I have seen clams show signs of stress while hardier SPS look fine. That said I have no idea what else you have in your reef.
Light spectrum - If your bulbs are old a small maxima would likely show signs of stress long before a derasa.
Light intensity - A maxima need a lot more light than a derasa. What kind of PAR is the maxima receiving?
Food - This is where I disagree with standard reef hobbyist information. While food plays a role in all clam species nutrition there is research that suggests different species of Tridacna clams rely less on filter feeding than others With the shallow-water species (such as maximas) relying more on light and less on filter feeding.
I'm sure there is more but that's what I can come up with right now.
A couple questions:
Is the clam still showing signs of growth? It would be especially troubling if it is not.
a few thoughts.... in no particular order.
Reply With Quote
