Xylocythere sarrazinae, a new cytherurid ostracod (Crustacea) from a hydrothermal vent field on the Juan de Fuca Ridge, northeast Pacific Ocean, and its phylogenetic position within Cytheroidea
This paper described Xylocythere sarrazinae sp. nov. (Ostracoda: Cytheroidea: Cytheruridae: Eucytherurinae), collected at 2196 m depth from the Grotto hydrothermal edifice (Main Endeavor Field, Juan de Fuca Ridge) in the northeastern Pacific Ocean. This new species was found living in association with Ridgeia piscesae tubeworm assemblages. It is the second representative of Xylocythere described from such vents. Xylocythere sarrazinae sp. nov. is easily distinguished from the seven described species of Xylocythere by the surface ornamentations of its carapace, with the most similar species to it being Xylocythere pointillissima Maddocks & Steineck, 1987. However, Xylocythere sarrazinae sp. nov can be distinguished from X. pointillissima based on the following characters: having a subsquare basal capsule outline, a spatulate upper ramus, a flattened distal lobe of the male copulatory organ, and having 15 maxillula branchial plate setae. We found that one specimen of this new species had multiple spherical objects associated with the internal openings of its pore clusters. These objects were quite similar in shape to that of chemoautotrophic bacteria, which were previously reported from the outer surfaces of pore clusters in other Xylocythere species. Finally, we provided a preliminary phylogenetic analysis of this new species based on 18S rRNA gene sequences to determine the phylogenetic position of the subfamily Eucytherurinae within the superfamily Cytheroidea. This analysis revealed that Xylocythere (Eucytherurinae) may be the most ancestral lineage among the Cytheruridae and identified paraphyletic relationships among the three subfamilies within Cytheruridae. This result supported certain previous studies’ conclusions based on morphology and fossil records.
KeywordsChemosynthetic habitat Crustacea Eucytherurinae Meiofauna Pore clusters
The authors thank the captain and crew of the R/V Thomas G. Thompson and the staff of Ocean Networks Canada and ROV’s Jason pilots during the “Ocean Networks Canada Expedition 2015: Wiring the Abyss” cruise. We thank also Kim Juniper and the government of Canada in obtaining of works permit to study in Canadian waters (XR281, 2015). We are also grateful to Thomas Day for his assistance in sample sorting and Akira Tsukagoshi for providing the research facilities for taxonomy and molecular work. This research was part of Yann Lelièvre PhD thesis supervised by Legendre, P. (Université de Montréal) as well as Mariolaine Matabos and Jozée Sarrazin (Université de Bretagne Occidentale/Ifremer).
This study was funded by the grants from the Japan Society for the Promotion of Science for Young Scientists (No. 263700) (to HT), the Research Grants Council of the Hong Kong Special Administrative Region, China (project codes: HKU 17306014, HKU 17311316) (to MY), Ifremer internal funds and a fellowship from the “Laboratoire d’Excellence” LabexMER (ANR-10-LABX-19) (to YL) and NSERC research grant to Pierre Legendre.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All applicable international, national, and/or institutional guidelines for the care and use of animals were followed by the authors.
Sampling and field studies
All necessary permits for sampling and observational field studies have been obtained by the authors from the competent authorities and are mentioned in the acknowledgements.
Data availability statement
Sequence data of Xylocythere sarrazinae sp. nov. that support the findings of this study have been deposited in GenBank with the accession codes LC380020 (https://www.ncbi.nlm.nih.gov/nuccore/LC380020.1).
- Baird W (1845) Arrangement of the British Entomostraca, with a list of species, particularly noticing those which have as yet been discovered within the bounds of the Club. Hist Berwicksh Nat Club 2:145–158Google Scholar
- Colalongo ML, Pasini G (1980) La ostracofauna plio-pleistocenica della sezione Vrica in Calabria (con considerazioni sul limite Neogene/Quaternario). B Soc Paleontol Ital 19:44–126Google Scholar
- van Harten D (1993) Deep sea hydrothermal vent eucytherurine Ostracoda: the enigma of the pore clusters and the paradox of the hinge. In: McKenzie KG, Jones PJ (eds) Ostracoda in the Earth and life sciences. Balkema, Rotterdam, pp 571–580Google Scholar
- Jones ML (1985) On the Vestimentifera, new phylum: six new species, and other taxa, from hydrothermal vents and elsewhere. Bull Biol Soc Wash 6:117–158Google Scholar
- Kajiyama E (1913) On the Ostracoda of Misaki (part 3). Zoological magazine (Dobutugaku-zasshi) 25:1–6 [In Japanese]Google Scholar
- Kelley DS, Carbotte SM, Caress DW, Clague DA, Delaney JR, Gill JB, Hadaway H, Holden JF, Hooft EEE, Kellogg JP, Lilley MD, Stoermer M, Toomey D, Weekly R, Wilcock WSD (2012) Endeavour segment of the Juan de Fuca Ridge: one of the most remarkable places on earth. Oceanography 25:44–61CrossRefGoogle Scholar
- Kornicker LS (1991) Myodocopid Ostracoda of hydrothermal vents in the eastern Pacific Ocean. Smithson Contr Zool 516:1–46Google Scholar
- Machian-Castillo ML, Gío-Argáez FR, Escobar-Briones E (2014) Foraminíferos y ostrácodos recientes de la zona batial y abisal del sur del Golfo de México. In: Low Pfeng A, Peters Recagno EM (eds) La frontera final: el océano profundo. INECC, Mexico, pp 153–173Google Scholar
- Müller GW (1894) Die Ostracoden des Golfes von Neapel und der angrenzenden Meeres-Abschnitte. Fauna Flora Golf Neapel 21:1–404Google Scholar
- Nylander JAA (2004) MrModeltest v2. Program distributed by the author. Evolutionary Biology Centre, Uppsala University, UppsalaGoogle Scholar
- Puri HS (1974) Normal pores and the phylogeny of Ostracoda. Geosci Man 6:137–151Google Scholar
- Rambaut A, Suchard MA, Xie MA, Drummond AJ (2014) Tracer v1.6. Available from: http://beast.bio.ed.ac.uk/Tracer [Accessed on 12 Feb 2018]
- Ramdohr AF (1808) Über die Gattung Cypris Müller und drei zu derselben gehörige neue Arten. Mag Ges Naturforsch Freunde Berl Neusten Entdeck Ges Naturkd 2:85–93Google Scholar
- Sars GO (1866) Oversigt af Norges marine Ostracoder. Forhandlinger i Videnskabs-Selskabet Christiania 8:1–130Google Scholar
- Schornikov EI (1974) Study of ostracods (Curustacea) from the intertidal zone of the Kurile Islands. Flora and Fauna in the intertidal zone of Kurile Islands. Inst Biol Morja Dal'nevost naucn Centr AN SSSR Sborn Rabot p 5–74 [In Russian]Google Scholar
- Szczechura J (1995) The ostracode genus Xylocythere Maddocks and Steineck, 1987, from the Middle Miocene of the Fore-Carpathian Depression, southern Poland (Central Paratethys), and its biogeographic significance. Acta Geol Pol 45:27–40Google Scholar
- Szczechura J (2000) Age and evolution of depositional environments of the supra-evaporitic deposits in the northern, marginal part of the Carpathian Foredeep: micropalaeontologica1 evidence. Geol Quart 44:81–100Google Scholar