The Largest Cnidae Among the Sea Anemones; Description of a New Haloclavid Species from Japan, Haloclava hercules (Cnidaria: Actiniaria: Enthemonae: Haloclavidae)

Abstract

Members of the family Haloclavidae, belonging to the order Actiniaria, are characterized by the presence of a large siphonoglyph next to their actinopharynx and an aboral end without a basal disc. Members of the genus Haloclava Verrill, 1899 have been reported primarily from Europe and America, and have not yet been described from Japanese waters based on the collected specimen. In this study, I describe a new species, Haloclava hercules sp. nov., from the Pacific coast of Japan. This new species is chiefly characterized by cudgel-like blunt massive tentacles with knob-like acrospheres in the outer tentacular cycle and gigantic basitrichs over 250 µm in length, which are the largest known from sea anemones.