I have a tank with an angle fish a dwarf gourami, a jumbo neon tetra, and a cory fish. there was a red tailed shark, but he seems to have disappeared. he usually hides inside the handle of the pot, in the volcano, the plants, or the log. i've check all his usual hiding places, around the outside of the tank and int he filter...he's no where to be seen. did the other fish eat him? what the heck happened?