Sea urchin

Biology

The sea urchin is a marine invertebrate that, similarly to the starfish, has no eyes but light-sensitive cells scattered throughout the body. When there are changes in the light, this creature hides under rocks, seaweed or shells. Even having tube feet and the body covered with spikes, it cannot always escape predators.

Curiosities

It gathers in groups and, with the help of its five teeth, scrapes algae and other invertebrates from which it feeds.