The different colors are all the same critter, just different colors. The Modern Aquaria #4 has some pictures of the fish basket I mentioned, plus it shows the serpeant stars being hatched in Mitch Gibbs' tank (Fishey Business/AquaticRevolution) all different colors from the same paremts. And man they are mean, I was propigating mushrooms in my tank, with fairly poor success for SOME reason. Every time I'd put a batch in the gravel tray, he'd run out and grab a few like footballs and make for the rubble pile. Needless to say, I'd never see them again.