Podocoryna tenuis (Hydrozoa) in temperate waters of the southwestern Atlantic: additional data on life cycle stages support its synonym with Podocoryna humilis

Two species of Hydractiniidae (Hydrozoa) with metagenetic life cycle have been recorded for the temperate region southwestern Atlantic Ocean: medusa stage Podocoryna tenuis and polyp P. humilis. Both adult humilis are unknown, but it is possible that they different stages same species, a hypothesis still to be tested. Colonies growing on southern king crab Lithodes santolla collected at Patagonian coast, two small medusae released from these hydroid colonies were analyzed. Medusa kept alive 3 days morphologically compared sorted out ~ 2,500 plankton samples along coast. The study specimens allowed reassessing taxonomic status Ocean. Polyp young described, additional information was recovered better describe tenuis. New morphologic biogeographic evidences in order propose synonymy between discussed.