Leptolida

an order of coelenterates of the class Hydrozoa. A polyp generation reproduces vegetatively, with new polyps appearing on and remaining attached to the stem and branches of the colony. Some species in the colonies have tentacles and mouths (feeding polyps), while others (blastostyles) do not and serve only for forming medusa buds. Some species also develop protective polyps. Medusa buds form primarily on the bodies of the polyps. In a number of species the medusa buds break away from the colony, becoming free-swimming medusae and reproducing sexually. In many other Leptolida the medusa buds are reduced and serve a sexual function without leaving the colony. There are approximately 2,500 known species, which are found in all seas; some species are found in fresh water.