Hi. I have a10 gallon saltwater tank. It started as a FOWLR but now has a light aqua colored sponge, some small brown polyps, coralline algae, and some kind of hair thin worms that build tubes which all came from the live rock (have yet to be able to identify the species of the invertebrates). I also have a peppermint shrimp, yellow clown goby, 3 tiny blue legged hermit crabs, 2 small red tipped hermit crabs, and 3 nassarius snails. I've been acclimating abeautiful guppy to the salinity of this tank. I put him in the tank today and he was doing fine until the lights had been off a while. I went back in to check on him about half an hour later I found him stuck halfway inside a hole in a piece of live rock. I thought he was dead and went to get a net and by the time I got back the peppermint shrimp had pulled him out and had him. Amazingly, the guppy survived. The question is, do I have something lurking in the hole (about 3/8 inch) or did something else happen? I can't lift the rock out of the water because it has the sponge growing on it.
