predators, bilateraly symmetrical, transparent with iridescent combs, diploblastic gastrodermis, mesoglea and epidermis. nerve network no specialized respiratory system. ciliated combs for locomotion called ctene arranged in eight rows. statoliths for balance. use sticky cells colloblast to capture prey. hermaphroditic gametes released into digestive tract and expelled through the mouth. embryo development is determinate and most species develop into a cydipid larva.