I am new to clams, and picked up a dursa a week ago (from everything i read so far they seam to be the easiest.) Though it seems happy, about every other day I come home and there is about a 7 inch long brown hair coming out of the exhalent siphon. It kind of looks as though its going to the bathroom. I tried to find out if this is normal but have not found a clear answer. From what I read it is either in fact going to the bathroom or expelling zooxanthellae. Does anyone know what it is, or if i should be concerned.