A mouse belongs to the group of vertebrates known as mammals.
Rodents and Mammals
Sea anemone are cnidarians.
Fish
Sea Stars, also know as starfish, belong to the animal group echinoderms.
Crustacean
Sea anemones, coral and jelly fish belong to the group of Cnidarians.
The sea cucumber belongs to the same animal group as the starfish, the echinoderms.
They belong to the class Anthozoa.
Sea urchin is a member of Echinoderm family
A mouse belongs to the phylum Chordata.
It's just a mouse that is on a ship at sea nothing big or scientific just a mouse that's out at sea.