Falcidenshalanychi, a new species of Chaetodermomorpha (=Caudofoveata) (Mollusca) from the northwest Atlantic Ocean

Abstract

During a cruise with R/V Oceanus out of Woods Hole organized by the National Science Foundation project WormNet, a new species of chaetodermomorph aplacophoran was found in the northwestern Atlantic on the continental rise, between 1100 and nearly 2900 m. An investigation into the material of older collections revealed that the species had previously been collected on numerous occasions but remained undescribed. We here describe the species under the name Falcidens halanychi sp. nov. The species is compared with F. limifossorides Salvini-Plawen 1992 that has the most similar overall morphology, but occurs in the eastern Pacific at lower slope and abyssal depths between 3700 and 4300 m. We illustrate the radula of limifossorides and the birefringent colours of the sclerites photographically for the first time. We also include two DNA barcodes of F. halanychi (cytochome oxidase I) to aid future molecular identification.

Keywords:

• Aplacophora
• COI
• DNA barcodes
• geographical distribution
• limifossorides
• radula
• sclerites

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

Acknowledgments

We thank Ken Halanych for inviting CS to participate in the WormNet cruise and for use of his molecular laboratory at Woods Hole Oceanographic Institution. Louie Kerr at the Marine Biological Laboratory, Woods Hole, helped with the scanning electron microscopy. Paula Mikkelsen at the American Museum of Natural History is thanked for the loan of material of F. limifossorides from the Vema expedition. The reviews of Benoît Dayrat and another reviewer were very helpful and we thank them. This research was funded by National Science Foundation PEET (Partnerships for Enhancing Expertise in Taxonomy) grant DEB-9521930 (to AS), by the Mary Sears Fund of the Woods Hole Oceanographic Institution (to AS), and by grants (to CS) from the Swedish Research Council (contract number 621-2002-313), the Colliander Foundation, the Swedish Species Information Centre, the Meltzer foundation, and by a start-up grant from the University of Bergen. Funding for shiptime for collecting material was provided by the National Science Foundation EAR-0120646 Biocomplexity: Genome-Enabled Science (Gen-En) – WormNet: Reconstructing the Early Evolution of Segmented annelid worms (to Ken Halanych).

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