Reevaluation and New Species of Kainonereis Chamberlin 1919(Annelida: Polychaeta: Nereididae)

摘要

Chamberlin, 1919 was proposed to include only onespecies, , based on epitokes provided with elytriform structuresin chaetigers 5-7. The species was thoroughly described and illustrated, but its uniquefeatures were enigmatic and the genus is currently regarded as . In order to have a better understanding of its diagnostic featuresand determine how this genus differs from similar ones, type material of and two other species bearing elytriform structures- Hartman, 1967 and Sun and Wu, 1979,including additional material from Gulf of California and Caribbean Sea-were examined.Because the type material is in good condition and the presenceof elytriform structures in chaetigers 5-7 is confirmed, this paper regards it as a validgenus. Given that the elytriform structures, or dorsal discs, together with a set ofdiagnostic features, are consistent in structure and position in all epitokes examined,they are regarded as homologous structures delineating .Consequently, is redescribed, the new combinations comb. n. and comb. n. are proposed andredescribed, and two new species are described: sp. n.from the Caribbean Sea, and sp. n. from the Gulf ofCalifornia. Also, the discovery of an atoke on comb. n.allowed us to better distinguish Kainonereis from the similar genera Kinberg, 1865 and Pettibone, 1971. A key toidentifying all known species is also included.