A new deep-sea benthopelagic chaetognath of the genus Bathyspadella (Chaetognatha) with ecological and molecular phylogenetic remarks

Abstract

A new chaetognath, Bathyspadella oxydentata, collected from Sagami Bay, central Japan, is described. The new species was collected from deep-sea benthopelagic habitat and is distinguished from the closely related species Bathyspadella edentata Tokioka, 1939 by the presence of teeth. The phylogenetic position of the new species was examined by molecular genetic analysis using partial sequences of 18S rRNA and 16S rRNA. Although B. oxydentata shares several morphological features with both Spadellidae and Eukrohnidae, the molecular phylogeny indicates that the new species is closely related to Heterokrohnidae species.

Keywords:

• arrow worm
• Bathyspadella oxydentata
• new species
• molecular phylogeny
• Japan

Acknowledgements

We would like to thank the captains and crew of the T/S Seiyou Maru and the R/S Tansei Maru, and the researchers who accompanied us for their cooperation at sea. We also thank Dr Yuji Tanaka (Tokyo University of Marine Science and Technology, Tokyo, Japan) for providing the samples. This study is part of the Census of Marine Zooplankton (CMarZ), an Ocean Realm Field Project of the Census of Marine Life.