Water Bear Echiniscoides sigismundi
This species of water bear lives in the spaces between sand grains in marine sediments, as do most of the other 25 or so marine species.
The rest of the 400 or so other species live in fresh water, especially in the thin layer of water around damp-loving plants such as mosses. Water bears have a short, plump body without a well-defined head but with eyespots and sensory appendages at one end.
There are four pairs of short stubby legs each ending in a bunch of tiny claws on which the animal lumbers slowly along. The relatively thick skin protects against abrasion from sand grains. The sexes are separate, but there are few males and the eggs can probably develop without being fertilized. The nearest relatives of these tiny animals are thought to be the land velvet worms of the phylum Onchophora.