Cooperband butterfly in a reef?

[Delphinus]

FWIW, mine is a smaller CBB (3") and I have clams ranging in size from 2.5" to 14". In all fairness he hasn't been a problem to the clams, and that incident with the new clam may just have been him "investigating" the new arrival (since all the other clams were in the tank long before he ever was).

But the main worry of mine, really, is his choice of foods. He's a hard fish to feed. Feeding mysis is easy enough but too much of it every day is hard on the bioload. I crashed my tank this way, so now I only feed mysis about once a week. So if you can find one that eats pellets and/or flakes, that would be golden.

Doug told me about the trick of feeding grocery store clams and that's basically what I do to offer this fish something to eat. My guess is that because the clams are cold water creatures in warm water, they're somewhat stressed and thus smell more like food than a healthy ornamental tridacnid clam would. However I'm willing to bet that if a tridacnid clam were to get sick or injured (and would thus start smelling more like "food" instead "tankmate to leave alone") that the tables would turn fairly quickly.