Fairy Shrimp

Anostraca is one of the four orders of crustaceans in the class Branchiopoda; its members are known as fairy shrimp. They live in vernal pools and hypersaline lakes across the world, and have even been found in deserts, ice-covered mountain lakes and Antarctic ice, typically measuring 6 to 25 millimeters long, though exceptionally up to 170 millimeters. Most species have 20 body segments bearing 11 pairs of leaf-like phyllopodia used for swimming, and the body lacks a carapace; fairy shrimp are known for swimming upside-down while filtering particles or scraping algae for food.