Deep-sea amphipod genus Eurythenes from Japan, with a description of a new Eurythenes species from off Hokkaido (Crustacea: Amphipoda: Lysianassoidea)
Two species of the giant deep-sea amphipod genus Eurythenes are reported from two bathyal habitats in Japanese waters based on a morphological examination and DNA analyses. The new species E. aequilatus collected off Hokkaido in the Sea of Okhotsk comprises a distinctive lineage within the known Eurythenes species and genetic groups. This finding sheds light onto the overlooked role of the marginal deep sea in the species diversification history of Eurythenes. Eurythenes specimens collected from the south off Okinawa Island in the Philippine Sea were identified as E. magellanicus, confirming the presence of a population in the western North Pacific. Past and present trans-oceanic dispersal of this species is briefly discussed based on the mitochondrial DNA sequences obtained from the Okinawa specimens of E. magellanicus.
KeywordsEurytheneidae Molecular phylogeny Cryptic species Pacific Ocean Long-distance dispersal
The authors are grateful to Keiichi Kakui (Hokkaido University), Atsushi Kaneko (Okinawa Churaumi Aquarium, OCA), and Kenta Yamada (OCA) for providing valuable specimens of Eurythenes species. We also express our sincere thanks to Hidetoshi Nagamasu (The Kyoto University Museum) for his helpful advice on a specific name for the new species, and to Cédric d’Udekem d’Acoz (Royal Belgian Institute of Natural Sciences) and one anonymous reviewer for their constructive comments and suggestions on this manuscript. Thanks are extended to the captain and crew of the R/V Soyo-Maru (Japan Fisheries Research and Education Agency). This study was partly supported by JSPS KAKENHI grant numbers JP25242015, JP25840140, and JP15J00720.
- De Broyer C, Lowry JK, Jażdżewski K, Robert H (2007) Census of Antarctic marine life. Synopsis of the Amphipoda of the Southern Ocean. Edited by Calude de Broyer. Volume 1: part 1. Catalogue of the Gammaridean and Corophiidean Amphipoda (Crustacea) of the Southern Ocean, with distribution and ecological data. Bull Inst R Sci Nat Belg Biol 77:1–324Google Scholar
- Escobar-Briones E, Nájera-Hillman E, Álvarez F (2010) Unique 16S rDNA sequences of Eurythenes gryllus (Crustacea: Amphipoda: Lysianassidae) from the Gulf of Mexico abyssal plain. Rev Mex Biodivers 81:177–185Google Scholar
- Eustace RM, Ritchie H, Kilgallen NM, Piertney SB, Jamieson AJ (2016) Morphological and ontogenetic stratification of abyssal and hadal Eurythenes gryllus sensu lato (Amphipoda: Lysianassoidea) from the Peru–Chile Trench. Deep Sea Res Part I Oceanogr Res Pap 109:91–98. doi: 10.1016/j.dsr.2015.11.005 CrossRefGoogle Scholar
- Hasegawa M, Kurohiji Y, Takayanagi S, Sawadaishi S, Yao M (1986) Collection of fish and Amphipoda from abyssal sea-floor at 30° N–147° E using traps tied to 10.000 m wire of research vessel. Bull Tokai Reg Fish Res Lab 119:65–75Google Scholar
- Havermans C, Sonet G, d’Udekem d’Acoz C, Nagy ZT, Martin P, Brix S, Riehl T, Agrawal S, Held C (2013) Genetic and morphological divergences in the cosmopolitan deep-sea amphipod Eurythenes gryllus reveal a diverse abyss and a bipolar species. PLoS One 8:e74218. doi: 10.1371/journal.pone.0074218 CrossRefPubMedPubMedCentralGoogle Scholar
- Rambaut A, Drummond AJ (2013) Tracer v1.6. Home page at: http://tree.bio.ed.ac.uk/software/tracer/. Accessed 24 May 2015
- Ronquist F, Teslenko M, van der Mark P, Ayres DL, Darling A, Höhna S, Larget B, Liu L, Suchard MA, Huelsenbeck JP (2012) MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model space. Syst Biol 61:539–542. doi: 10.1093/sysbio/sys029 CrossRefPubMedPubMedCentralGoogle Scholar
- Scudder SH (1882) Nomenclator Zoologicus. An alphabetical list of all generic names that have been employed by naturalists for recent and fossil animals from the earliest times to the close of the year 1879. In two parts: I. Supplemental list. II. Universal index. U.S. National Museum, WashingtonCrossRefGoogle Scholar
- Stoddart HE, Lowry JK (2004) The deep-sea lysianassoid genus Eurythenes (Crustacea, Amphipoda, Eurytheneidae n. Fam.). Zoosystema 26:425–468Google Scholar
- Tanabe AS (2008) Phylogears v2.0.2014.03.08. Home page at: http://www.fifthdimension.jp/. Accessed 24 May 2015
- Umezu T (1982) Deep-sea pelagos. Part II. Collection by RV KAIYO-Maru for radionuclide analysis. Aquabiology (Tokyo) 4:2–9Google Scholar
- Umezu T (1984) Deep-sea biomass in North Pacific polar frontal zone 40° N–150° E: collected by KOC-net from 150–4500 m depth in May 1981. Bull Tokai Reg Fish Res Lab 113:115–139Google Scholar