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| Bathynomus yucatanensis Huang, Kawai & Bruce, 2022 |
ABSTRACT
Bathynomus jamesi Kou, Chen and Li, 2017 from Zhengbin fishing port in Keelung, Taiwan, was identified by the shape of the distolateral corner of the uropodal endopod, the shape of the clypeus, and the nucleotide sequences of the COI (cytochrome c oxidase subunit 1) and 16S rRNA genes. Only two species of Bathynomus have previously been recorded from Taiwan, B. doederleini Ortmann, 1894 and B. decemspinosus Shih, 1972. Bathynomus kensleyi, previously known from the South China Sea as well as the south-east Swain Reefs, Coral Sea, was primarily differentiated by the elongate and upturned pleotelson spines, but that character is now shown to also occur in mature Bathynomus jamesi. Two specimens from the Gulf of Mexico (obtained from the Enoshima Aquarium in Japan) were compared to species of Bathynomus from the western North Atlantic. Sequence data showed that one of two samples was not B. giganteus Milne-Edwards, 1879, as had been assumed, and it did not match any other species of Bathynomus. That specimen was collected off the Yucatán Peninsula and is morphologically distinct from both B. giganteus (in the relative length of the antennal flagellum and the length:width ratio of the pleotelson) and B. maxeyorum Shipley, Brooks, and Bruce in Shipley et al., 2016 (the number of pleotelson spines is seven and the distolateral corner is produced on the uropodal exopod). Therefore, it is here described as Bathynomus yucatanensis sp. nov. Bathynomus is currently a very minor fisheries resource in Taiwan and Japan, but this find demonstrates the continuing importance of the fishing industry to marine biological exploration.
KEYWORDS: Cirolanidae, South China Sea, Taiwan, Bathynomus kensleyi, Bathynomus yucatanensis sp. nov
Order Isopoda Latreille, 1817
Family Cirolanidae Dana, 1852
Genus Bathynomus Milne-Edwards (1879)
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| Bathynomus yucatanensis (voucher no. TMCD003335). Body length 260 mm. Dorsal view and ventral view. |
Bathynomus yucatanensis sp. nov.
Diagnosis: Clypeus with straight lateral margins. Antennal flagellum extending to within pereonite 3. The distal part of the coxa of pereopod 7 is broad. Uropodal exopod not extending beyond pleotelson: endopod with distolateral corners slightly produced. Length:width ratio of pleotelson approximately 0.8:1; number of pleotelsonic spines 11 or 13, short, or straight.
Habitat: Captured with B. giganteus, presumably similar to B. giganteus.
Distribution: Off the Yucatán Peninsula of Mexico, and in the Gulf of Mexico; approximate depth range 600–800 metres.
Etymology: The epithet is an adjective derived from the name of the nearest land mass to its common locality, the Yucatán Peninsula. The Japanese name: Enosuigusokumushi.
Ming-Chih Huang, Tadashi Kawai and Niel L. Bruce. 2022. A New Species of Bathynomus Milne-Edwards, 1879 (Isopoda: Cirolanidae) from the southern Gulf of Mexico with A Redescription of Bathynomus jamesi Kou, Chen and Li, 2017 from off Pratas Island, Taiwan. Journal of Natural History. 56(13-16);885-921. DOI: 10.1080/00222933.2022.2086835
