Description of Echthrogaleus spinulus n. sp. (Copepoda: Pandaridae) parasitic on a torpedo ray from the central Pacific Ocean utilising a morphological and molecular approach
A new species of parasitic copepod, Echthrogaleus spinulus n. sp. (Pandaridae), is described from the torpedo ray Tetronarce tokionis (Tanaka) (Torpedinidae) captured in pelagic Hawaiian waters. The new species has pediger 4 bearing large dorsal plates with denticles on posterior margin, genital complex with posterolateral lobes widely curved medially and overlapping, leg 4 exopod incompletely 3-segmented, and the largest body size (maximum length 16 mm from anterior rim of frontal plates to tip of caudal rami, excluding setae). This morphology does not match any of the seven valid species of Echthrogaleus Steenstrup & Lütken, 1861. Analysis of 28S rDNA sequences separated the new material from the Central Pacific from samples of E. coleoptratus in the Atlantic and Eastern Pacific Oceans. However, due to the lack of DNA sequences in the databases, the new 28S rDNA sequence cannot used to confirm the species identity. The unique morphological characteristics of the Central Pacific female copepods combined with 28S rDNA sequencing was used as a basis to validate the new species.
This paper is dedicated to George Benz, a true force in copepod discovery and friend. We thank K. Jurow of the Pacific Island Region Observer Programme of the NOAA/NMFS/PIFSC for collecting the torpedo ray and S. Arceneaux, K. Forney, J. Kelly for research assistance. The support from the FV Vui Vui longliner, Captain L. V. Pham and crew G. Villasrosa, D. Salvo, V. Quang, E. Ebiata and K. Terrera is appreciated. The NOAA/NMFS/PIFSC program for laboratory support especially J. O’Malley, Bruce Mundy, R. Humphreys, Jr and M. Lee. The Argentina copepod specimen was collected by Claudio Serrano (Museo de Historia Natural Patagonia) and processed for molecular analysis by Walter Ferrari. This research was supported by Ocean Research Explorations. The CLSM images were taken at the University of Hawaii at Manoa, PBRC, Biological Electron Microscope Facility with support from T. Carvalho and M. Dunlap and NSF grant # 1828262. We acknowledge D. Catania CAS, H. Bolick BPBM for the specimen curation and Jennifer Crites for her help with figures. This research was facilitated while (GLC) was a visiting scientist at PIFSC. This is Ocean Research Explorations Hawaiian Islands Biodiversity Project publication 01.
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Conflict of interest
The authors declare that they have no conflict of interest.
All applicable institutional national and international guidelines for the care and use of animals were followed.
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