26 facts about Brittle stars
Although ophiuroids resemble starfish, they are quite different from them.
First, they move with their flexible arms, whereas starfish use tube feet ...
Jellyfish are fascinating creatures and the most ancient animals on Earth. Although boneless, toothless, and brainless, they are efficient predators armed with invasive toxins. There are so widespread, there are no water tanks not filled with at least one species.