I have a Crocea clam in my 75 gallon tank. I noticed this morning that it is somewhat pale in color and it is not responding well to stimulus. It's shell is mostly open and I think it is dying. I did move it higher up in the tank hoping that it may survive, but I have serious doubts. I think one of my MH bulbs is failing and I ordered a new one yesterday. Here's my question: How does one humanely euthanise an ailing clam. I really hate to have anything "suffer." By the way, it has been very healthy up until yesterday or the day before. It gets regular supplements of iodine and other trace elements. Otherwise the water parameters are all within recommended levels.