Fairy shrimp are small crustaceans related to sea shrimp.
They are seldom more than 2.5 cm long and usually much smaller. They have 11 to 17 pair of leaf-like appendages, you could hardly call them legs, that look feathery. The brine shrimp, often sold in pet shops, is a salt-water fairy shrimp. It is a close relative of the pond fairy shrimp. Pond fairy shrimp swim on their backs by making a current with their appendages.