Daphnia longispina is a planktonic crustacean of the genus Daphnia (Family "Daphniidae"), a cladoceran freshwater water flea. It is native to Eurasia. D. longispina is similar in size and sometimes confused with the often sympatric D. pulex (a very common species), but much smaller than D. magna. D. longispina is found in a wide range of standing freshwater bodies from small, ephemeral rock-pools to large lakes.