New data on the genus Paracentrophyes (Homalorhagida, Kinorhyncha), with the description of a new species from the West Pacific

Abstract

The kinorhynch genus Paracentrophyes currently consists of two species only: P. quadridentatus (Zelinka, 1928) from the Mediterranean Sea and P. praedictus Higgins, 1983 from Belize in the Caribbean. Both species have until now been recorded from their type localities only. In the present contribution a new species of Paracentrophyes, P. anurus sp. nov., is described from the Korea Strait. The species can be recognized by details in the mouth cone morphology, absence of perispinal setae in segment 10, and absence of a midterminal process in both sexes. Female specimens are furthermore characterized by the presence of an extraordinary long middorsal spine on segment 10, whereas males possess a midterminal type 3 sensory spot. Besides the recording of the new species, the occurrence of P. cf. quadridentatus is reported from two localities in the Atlantic Ocean (Faeroe Islands and Spain). The recorded specimens are described in detail, based on combined examinations with LM and SEM, and diagnostic traits for all three species of Paracentrophyes are discussed in light of the newly acquired information. Furthermore, an emended terminology for positions of cuticular trunk structures is proposed.