Crossotonotus spinipes (De Man, 1888 )

Takeda, Masatsune & Tachikawa, Hiroyuki, 2015, Crabs of the families Palicidae and Crossotonotidae (Crustacea, Decapoda, Brachyura, Palicoidea) from the Ogasawara Islands, Japan, with the description of a new species, Zootaxa 3918 (1), pp. 141-150 : 143-144

Crossotonotus spinipes (De Man, 1888)

( Fig. 1 B)

Selected synonymy:

Pleurophricus spinipes De Man 1888: 344 , pl. 15 fig. 1. Manella spinipes — Rathbun 1906: 837, fig. 3, pl. 7 fig. 6.— Sakai 1939: 610, pl. 103 fig. 3. Manella gardineri Rathbun 1911: 240 , pl. 20 fig. 9.

Manella brevimana Ward 1933: 387 , pl. 21 figs. 7, 8.— Moosa & Serène 1981: 54, figs. 12 a, b, 13 a. Crossotonotus spinipes — Sakai 1965: 187, fig. 25, pl. 89 fig. 4; 1976: 506, pl. 206 fig. 1.— Chen 1975: 167, fig. 9, pl. 2 fig. 3.— Holthuis 1977: 187.— Dai et al. 1986: 414, fig. 229A.— Dai & Yang 1991: 451, fig. 229A.— Castro 2000: 574, figs. 45, 46, 51 (synonymy); 2010: 84.

Crosstonotus [sic] taketomiensis — Nagai & Nomura 1988: 197, 1 fig. [not C. taketomiensis Sakai, 1974 = C. compressipes A. Milne-Edwards, 1873 ]

Material examined. Mizutama Bay, Ani-jima I., Ogasawara Is., 3 m; 1 juvenile (cb 6.5 mm, cl 6.2 mm), CMNH- ZC 02476; February 9, 1995; H. Tachikawa leg.

Takinoura Bay, Ani-jima I., Ogasawara Is., 2 m; 1 immature female (cb 9.5 mm, cl 8.5 mm), NSMT-Cr 22987; March 1996; H. Tachikawa leg.

Remarks. The specimens examined ( Fig. 1 B) are small, but this species may attain a much larger size exceeding 40 mm in carapace breadth as recorded by Castro (2000). In the large specimen the dorsal bosses and marginal tubercles of the carapace are strongly developed, both chelipeds are unequal and markedly developed, and the frontal teeth of the carapace are thick and curved dorsally at the tips, with the distinctly bifid median pair. In the small specimens from the Ogasawara Islands, however, the frontal teeth of the carapace are sharply developed forward, nearly spiniform and not upturned. This discrepancy is without doubt due to the developmental variation. Castro (2000) reduced Crossotonotus taketomiensis Sakai, 1974 to a synonym of C. compressipes A. Milne- Edwards, 1873. There are no doubts for this synonymy because of the examination of the type specimens of both species by Castro, in addition to the close similarity of the original figures of both species ( A. Milne-Edwards, 1873a: Pl. 6 fig. 6; Sakai, 1976: Fig. 326). Castro (2000) explained the live coloration of C. compressipes based on the photograph of C. taketomiensis given by Nagai & Nomura (1988: 197). The photograph, however, shows that the external orbital tooth and the anterolateral marginal teeth of the carapace are strongly developed as seen in C. spinipes , indicating that this photographed specimen is C. spinipes , not C. taketomiensis . The identification of Nagai & Nomura (1988) as C. taketomiensis should be corrected to C. spinipes , and therefore the live coloration of C. compressipes explained by Castro (2000) should be referred to that of C. spinipes .

Distribution. Indo-West Pacific from the Red Sea and the western Indian Ocean to Samoa, Japan and the Hawaiian Islands in the Pacific Ocean, with bathymetric range from the intertidal zone to 146 m.

Figures

FIGURE 1. A, Neopalicus jukesii (White, 1847), male (cb 5.8 mm, cl 5.3 mm), CMNH − ZC 0 2475. B, Crossotonotus spinipes (De Man, 1888), immature female (cb 9.5 mm, cl 8.5 mm), NSMT-Cr 22987. C, Pleurophricus stellatus sp. nov., male (cb 5.7 mm, cl 5.2 mm), holotype, NSMT-Cr 22988.