It's hard to see in this picture but there is a crayfish right in the center of the photo. There are three in this tank right now about an inch long. The aquarium shop was selling them for .26 cents a piece so I thought I'd take take a chance. Crayfish isn't one of my favorite shellfish but it's nice once in a while. If nothing else, I can cut them up and feed them to the tilapia.