The gelatinous macroplankton community at the hatoma knoll hydrothermal vent

Abstract

A series of dives around the Hatoma Knoll, Okinawa Trough, have revealed a diverse community of gelatinous midwater animals. Many of these animals are potential predators of the larvae of hydrothermal vent-associated organisms. Due to the lack of published information on the midwater fauna of the Okinawa Trough, this paper endeavours to present a synopsis of the macroplanktonic gelatinous faunal elements present in and around the vent site at all depths where vent larvae may occur—from the surface to the benthopelagic layer. Three pelagic tunicates, eight ctenophores, seven siphonophores, eight hydrozoan medusae and two syphozoan medusae were recognized. Taxonomic treatments and comments on distribution and ecology are provided where such information exists.