Taxonomic Study on Hydrocoryne miurensis (Hydrozoa : Hydrocorynidae) in Japan

Abstract

The life cycle, nematocyst equipment, and the chromosomes of Hydrocoryne in Japan were studied from the taxonomic point of view. The morphology of Hydrocoryne was described and illustrated in the following developmental stages: the well-developed polyp with or without medusa buds, the regenerated polyp, the primary polyp, the newly liberated medusa, the earliest mature medusa, the aged mature and spent medusae, and the young and aged planulae. The morphology of gametes was also described and illustrated. It is highly probable that only one species, referable to H. miurensis Stechow, 1907, occurs in Japanese waters.