Ethusina alcocki Ng &amp; Ho 2003, new species
Creators: name: Ng, Peter K. L.
name: Ho, P. - H.
Publisher: name: Zenodo
Year: 2003
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Ethusidae
Ethusina
Ethusina alcocki

description: <i>Ethusina alcocki</i>, new species (Figs. 4, 5) <i>Ethusina investigatoris</i> – Chen &amp; Xu, 1991: 60, Fig. 9 (not <i>E. investigatoris</i> Alcock, 1896) <i>Material examined. –</i> Holotype - female, 8.2 by 9.8 mm (NTOU), Station CP 32, 22 01.7'N, 120 11.1'E, 910-1129 m, coll. TAIWAN 2000, R. V. "Fishery Researcher 1", 30 Jul.2000. <i>Etymology. –</i> This species is named after A. Alcock, whose contributions to Indian carcinology have not been rivalled. <i> <i>Remarks. –</i> Ethusina alcocki</i> , new species, is rather close to <i>E. investigatoris</i> Alcock, 1896, but three characters argue against its inclusion there. In <i>E. investigatoris</i>, the median frontal teeth are more prominent, with the inner margin more convex, the supraorbital margin is relatively narrower, and the dactylus of the P2 and P3 is about one-third shorter and relatively broader (cf. Alcock, 1896: 295; Alcock &amp; MacGilchrist, 1905: Pl. 72 fig. 3). Chen (1986b: 135, Fig. 14) referred a male specimen from China to <i>E. investigatoris</i>, and this seems to be correct. Chen &amp; Xu (1991: 60, Fig. 9) subsequently reported <i>E. investigatoris</i> from the South China Sea, but the external orbital spine of the male specimen she figured is relatively shorter with the median frontal teeth subequal in length (rather than with the outer tooth longer). Recently, through the courtesy of H.-L. Chen, the first author had an opportuinity to examine a second specimen from the South China Sea which had been identified as " <i>E. investigatoris</i> " and is almost identical to that described by Chen &amp; Xu (1991). We have no doubt that this specimen is conspecific with what is here identified as <i>E. alcocki</i>. Unfortunately, the original specimens described in Chen (1986) and Chen &amp; Xu (1991) could not be located for direct comparisons as the IOCAS is currently moving its catalogued collections to a new building and the material is not available for study (H.-L. Chen, pers. comm., September 2002). Alcock (1896: 285) described <i>E. investigatoris</i> from the Laccadive Sea and Bay of Bengal, in the Indian Ocean, noting that the elongated external orbital spine is "needlelike" but "falls considerably short of the tips of the rather long acute frontal spines" (see also Alcock &amp; MacGilchrist, 1905: Pl. 72 fig. 3), and felt that it was very close to <i>E. gracilipes</i> (Miers, 1886). <i>Ethusina alcocki</i>, however, differs from <i>E. gracilipes</i> in having the external orbital spine relatively longer, reaching to the tip of the frontal spines (not falling short of it), and the inner median teeth are also lower and are not spiniform.
description: Published as part of <i>Ng, Peter K. L. &amp; Ho, P. - H., 2003, On The Deep-Water Dorippid Crabs Of The Genus Ethusina Smith, 1884 (Crustacea: Decapoda: Brachyura) From Taiwan, pp. 71-85 in Raffles Bulletin of Zoology 51 (1)</i> on pages 74-75, DOI: 10.5281/zenodo.4619337
description: {"references": ["Alcock, A., 1896. Materials for a carcinological fauna of India. No. 2. The Brachyura Oxystoma. Journal of the Asiatic Society of Bengal, 65 (2): 134 - 296, pls 6 - 8.", "Chen, H. - L., 1986 b. Studies on the Dorippidae (Crustacea, Brachyura) of Chinese waters. Transactions of the Chinese Crustacean Society, 1: 118 - 139.", "Miers, E. J., 1886. Report on the Brachyura collected by H. M. S. ' Challenger' during the years 1873 - 1876. In: Report on the Scientific Results of the Exploring Voyage of H. M. S. ' Challenger', Zoology, Part 49, 17: 1 - 362, 29 pls."]}