Anostraca Fairy shrimp The fairy shrimp of the order Anostraca are usually 6–25 mm (0.24–0.98 in) long (exceptionally up to 170 mm or 6.7 in).[6] Most species have 20 body segments, bearing 11 pairs of leaf-like phyllopodia (swimming legs), and the body lacks a carapace.[7] They live in vernal pools and hypersaline lakes across the world, including pools in deserts, in ice-covered mountain lakes and in Antarctica. They swim "upside-down" and feed by filtering organic particles from the water or by scraping algae from surfaces.[6] They are an important food for many birds and fish, and are cultured and harvested for use as fish food.[8] There are 300 species spread across 8 families.[9] Cladocera Water fleas The water fleas - around 620 species so far. Lipostraca Extinct Lipostraca contains a single species, Lepidocaris rhyniensis.

Notostraca Tadpole shrimp The tadpole shrimp or shield shrimp.[15] The two genera, Triops and Lepidurus, are considered living fossils, having not changed significantly in outward form since the Triassic Phyllopoda Clam shrimp Cyclestherida Laevicaudata Spinicaudata Laevicaudata, Spinicaudata and Cyclestherida