Will too much light kill a clam ?


New member
I just got a crocea clam a week ago and he is currently sitting at the bottom of my 46 gal bow front with a 250watt Metal Halide over it. The MH is running aqualine 10k bulb, its about 6 inches from water level and i think about 18 inches from the clam (i lost my measuing tape) . The Mh is on about 12 hours a day and no other lights. Well since i got my clam i notice his meat or innerds (not sure what you call it) has been extended out more lately. Does this mean his dieing or wants more light. I;m thinking hes dieing because he's getting too much light. Any advice, i'm a newbie. thanks a bunch
By "meat or innerds", I'll assume you mean the mantle (the coloured part of the clam tissue). This extending is a good sign, I have a 5.5" squamosa that extends its mantle 2" past the shell.
To answer your question, too much light can kill a clam but usually only if the light is suddenly increased. Clams are Highly light tolerant but light acclimation is essential for large changes in light intensity.
Can you get a photo of your clam?
Crocea clams are light-demanding. They are usually in clear water with significant current. They require alot of light to survive. They have a large byssus that enables them to attach and bore into rock.
The 'meat' or I think you mean mantle is brightly colored and extends over the rim of the shell when healthy. If there is some other organ protruding from the incurrent siphon this is not a healthy sign.
I would recommend doing some reading. Knop's book is excellent or link to reefs.org for aquarium frontiers article 'on the half shell'-there is an article on Croceas.
Health status questions can be better addressed when water parameters are known in addition to tank setup. Try to include these.
I would acclimate the clam slowly towards the surface over the next week. Find a position ~12 inches under the halides in some current and the clam will attach readily. Good luck.
HAHAHA, O so thats what its called, the Mantle. Sorry i don't have a digital camera yet, but thats probably my next "reef related" purchase. Thanks a bunch guys. I checked my water and its ok and i acclimated slowly and so I believe my clam is doing ok. But i will keep researching and reading to learn more about clams. Once again, i love this site. thanks a bunch fellow reefers.
its a bit concerning however that you are a newbie and you purchased a corcea clam which is not a beginner type item. Just as helpful reference, you should never purchase livestock which you dont know the needs/demands of, it will lead to problems, which cost $$. Just a little FYI-Guru
Agreed. I very strongly urge you to read "Giant Clams" by Daniel Knop. Crocea clams are very demanding creatures.

If anything, I think your clam would be better properly attached with his byssal organ higher up on your rockwork.