Redescription of Scymnodon ichiharai Yano and Tanaka 1984 (Squaliformes: Somniosidae) from the western North Pacific, with comments on the definition of somniosid genera


The somniosid species Scymnodon ichiharai Yano and Tanaka 1984 is redescribed based on the type specimens and additional material from Taiwan and Japan. The range of this species is extended to include Taiwanese waters. Although recently allocated to the genus Zameus, this species is very similar to Scymnodon plunketi from the southern Indo-West Pacific; our molecular evidence indicates that these species are sister-taxa. The genus Proscymnodon Fowler 1934 is placed in the synonymy of Scymnodon Barboza du Bocage and de Brito Capello 1864 and new generic definitions are provided for Scymnodon and the closely related Zameus. The genus Scymnodon is considered to include at least the species S. ichiharai, S. plunketi, and S. ringens; Proscymnodon macracanthus (Regan 1906) is allocated to Scymnodon, but its validity is uncertain. The genus Zameus is considered to be monotypic, containing only the species Z. squamulosus.

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We would like to acknowledge the following museum staff for their assistance in accessing collection material examined during this study: Alastair Graham (CSIRO, Hobart); Mamoru Yabe and Toshio Kawai (HUMZ, Hakodate); Oliver Crimmen and James Maclaine (BMNH, London); Gento Shinohara, Masanori Nakae, Fumihito Tashiro and Eri Katayama (NSMT, Tsukuba), John Sparks, Melanie Stiassny, Barbara Brawn, Radford Arrindel and Robert Schelly (AMNH, New York); and Richard Vari and Jeff Williams (USNM, Washington DC), and Paul Clerkin (Pacific Shark Research Center, Moss Landing Marine Laboratories, Moss Landing, California). DFBV and MRC are particularly grateful to Sho Tanaka (TMFE, Shimizu) for his hospitality, generosity, and for sharing his knowledge of somniosids during our visits to his laboratory in 2013. We would also like to thank the following people for their important technical contributions to this paper: Peter Last (CSIRO, Hobart) for his advice and vast knowledge of Indo-Pacific chondrichthyans; John Pogonoski (CSIRO, Hobart) for the radiographs and technical editing of the manuscript; Louise Conboy (CSIRO, Hobart) for the excellent denticle images; Carlie Devine (CSIRO, Hobart) for image preparation; Rou-Rong Chen and Yo-Jong Lin (National Museum of Marine Biology and Aquarium, Pingtung) for radiographs and curatorial assistance in Taiwan. This project was supported by a National Science Foundation (NSF) grant (Jaws and Backbone: Chondrichthyan Phylogeny and a Spine for the Vertebrate Tree of Life; DEB-01132229). DAE would like to acknowledge institutional support provided by Moss Landing Marine Laboratories. The National Science Council, Taiwan and National Museum of Marine Biology and Aquarium, Taiwan, supported a chondrichthyan biodiversity workshop in Taiwan in March 2012 which allowed examination of the material from this region. DFBV, MRC, and MC are supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) through grants 2012/07712-3, 2013/13137-4, 2012/09877-0, 2012/02349-5, 2012/05152-0, 2012/05391-5, 2012/05152-0, and 2013/05292-0; MRC is also funded by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (304615/2011-0).

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Correspondence to William T. White.

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This article was registered in the Official Register of Zoological Nomenclature (ZooBank) as E611CBD2-30ED-400A-8550-EFDC574D433F.

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White, W.T., Vaz, D.F.B., Ho, HC. et al. Redescription of Scymnodon ichiharai Yano and Tanaka 1984 (Squaliformes: Somniosidae) from the western North Pacific, with comments on the definition of somniosid genera. Ichthyol Res 62, 213–229 (2015).

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  • Zameus
  • Proscymnodon
  • taxonomy
  • synonymy
  • morphology