If you see this enormous flatworm in your tank, siphon it out. It is a predatory flatworm, and its food is often clam flesh. Their pattern is designed to act as a camoflage to match the mantle of a clam, so it can park on the animal as it consumes it. This flatworm can devour snails quite easily. Blanketing its prey as it pushes its stomach into the aperture of the snail, to feed upon the meaty snack. Not Reef-safe.