Crayfish

I used to keep a small tank of fish a long time ago. Then it all became a bit too much work. However, it must still be a popular pastime because our local garden centre has an extensive area devoted to tanks of fish, and even reptiles. I captured this fine crustacean atop the coral. The little fish in the lower left corner has such excellent camouflage that I didn't notice it until I cropped the picture.

It must be interesting for children to see crayfish moulting as they grow. When ready, the creature rolls onto its back and begins fanning its pincers and legs to increase oxygen levels. The carapace then begins to crack behind the head, and the new appendages pierce the old shell. After about five minutes, there's a sudden twist and the old shell detaches.