Someone please give me advice ASAP!!! My domino damsel, who usually terrorizes the clownfish in my tank, has been hiding behind a rock for the past few days. He hasn't come out from behind there at all-even to eat. This is unusual because he usually always comes up to the top when he's hungry. At feeding time, he is never timid-he eats like a pig! But now he doesn't eat, and he is also breathing heavy. Could this be due to the fact that the nitrate level is too high or that the salinity is too low? PLEASE HELP-I DON'T WANT HIM TO DIE...this fish means a lot to me. My boyfriend caught him for me in the ocean when he was just a little tiny thing.