A new species of the rare genus Sphenoderes (Cyclorhagida, Kinorhyncha), with differential notes on S. indicus Higgins, 1969

Abstract

A new species of the rarely recorded kinorhynch genus Sphenoderes was collected in the Korea Strait and East China Sea. The new species, Sphenoderes poseidon sp. nov., is distinguished by the presence of lateroventral cuspidate spines on segments 5 and 9 only, opposed to cuspidate spines on segments 5, 8 and 9 as found in S. indicus. The new species is furthermore characterized by having the special head aperture that is diagnostic for species of Sphenoderes, but yet possessing a segment 1 composed of a single, closed cuticular ring, rather than a dorsal, a ventral and two lateral plates as found in S. indicus. The description of Sphenoderes poseidon sp. nov. includes the first scanning electron microscopical examinations of cuticular details in a species of Sphenoderes. The new information is discussed and a comparison is made with the putative closely-related species S. indicus, as well as with other species more generally across the Kinorhyncha.

Keywords:

• Kinorhynch
• meiofauna
• phylogeny
• Sphenoderes
• taxonomy

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Acknowledgements

We wish to thank Stine Elle for preparing the line art illustrations and the Smithsonian Institution for loaning us specimens of Sphenoderes indicus. We are furthermore indebted to Dr Won Gi Min and Taewook Kang for their assistance in collecting samples. This work has been conducted with support through the research program of KORDI with contract number PP00751 to DSK and HSR, and by the Danish Natural Science Research Council (Grant No. 272-08-0576) to MVS.

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark