Scopimera globosa De Haan 1835

Scopimera globosa De Haan, 1835

(Figs. 1 a, b, 2a, b, 3a–c, 4a, b, 6)

Ocypode (Scopimera) globosa De Haan 1835: 53, pl. 11 (3, 3a, 3b), pl. C.

Scopimera globosa — H. Milne Edwards 1852: 153. – Ortmann 1894: 747. – Koebel 1897: 713. – Parisi 1918: 97, fig. 2. – Tesch 1918: 46, pl. 3(3). – Kemp 1919: 312, pl. 12(2). – Yokoya 1928: 779. – Shen 1932: 253, pl. 10(5), text-figs. 155, 157. – Sakai 1934: 320; 1935: 214, pl. 59(4); 1939: 636, pl. 72(4); 1965: 191, pl. 91(1); 1976: 621, pl. 212(2); 1982: 714 (in part). – Kamita 1941: 175, text-fig. 96. – Nishimura & Suzuki 1971: 121, pl. 44(9). – Kim 1973: 641. – Takeda 1975: 144, 243 (in part); 1982: 212; 1994: 260. – Miyake 1983: 168 (in part). – Dai & Yang 1991: 496, fig. 253(2), pl. 63(5) (in part). – Yamaguchi & Baba 1993: 506, fig. 195. – Minemizu 2000: 309. – Ng et al. 2008: 235 (in part).

Scopimera tuberculata Stimpson 1858: 98; 1907: 102.

Material examined. Lectotype and paratype: 2 males (RMNH 282), Japan, 1823–1829, coll. Ph. F. von Siebold.

Additional material. Japan: 7 females (NSMT-Cr-3729), Usu Bay, Hokkaido, 27 Jul. 1934, coll. M. Iwasa; 2 males, 2 females (NSMT-Cr-3739), Funabashi, Chiba, 17 Apr. 1957; 3 males (NSMT-Cr-3741), Moiwa, Sopporo; 1 male (NSMT-Cr-6504), Tokyo Bay, 7 Mar. 1977, coll. M. Suzuki; 2 males, 2 females (NSMT-Cr-6797), Ena Bay, Kanagawa, 15 Jun. 1980, coll. M. Takeda; 5 females (CBM-ZC-7979), Usu Bay, Hokkaido, 18 Aug. 2004, coll. T. Komai; 10 males, 2 females (CEL-CRU-2008-02), Wakayama, 7 Aug. 2008, coll. B. K. K. Chan.

Diagnosis. External maxillipeds merus slightly shorter than or subequal to ischium; external orbital angle blunt, crests behind external orbital angles diverging posteriorly (Figs. 1 a, 6); cheliped length more than twice of carapace length in mature males, carpus elongated; tooth on inner margin of movable finger triangular (Fig. 2 a); male sixth abdominal somite approximately as broad as long (Fig. 2 b); G1 slender, tip rounded, with inward radiating setae of similar length (Fig. 3 a, b, c).

Description. Carapace inflated, slightly broader than long, regions indistinct, surface covered by rounded tubercles, being densest on branchial regions, smooth on cardiac and intestinal regions; posterior margin longer than width between both external orbital angles (Figs. 1 a, 6); suborbital ridge lined with at least 20 equal-sized small rounded granules (Fig. 1 b); external orbital angle obtuse, directing slightly anterior, leaving single notch along lateral border, followed by longitudinal crest extending two-thirds of carapace length (Figs. 1 a, 6). Pterygostomian regions covered with rounded granules (Fig. 1 b). External maxillipeds convex, outer surface covered with rounded tubercles, merus slightly smaller than ischium, suture between them oblique, dactylus of palp just reaching suture. Ventral surface devoid of setae except short dense tufts of light-colored soft setae between bases of first and second ambulatory legs.

Entire cheliped covered with fine granules, total length about twice of carapace length in adult males, merus with single longitudinal ovate tympana on inner surface; carpus longitudinally ovate, slightly shorter than merus in adult males; palm as long as merus and fingers; tips of both fingers tapered to sharp points, inner margins of both weakly serrated, movable finger with faint triangular tooth on inner margin (Fig. 2 a). Ambulatory legs relatively elongated, slender, first and second legs longest, subequal to each other; fourth leg shortest; merus laterally compressed, tympana entire, occupying most of segment; dactylus tapered to sharp tip, slightly longer than propodus; fourth dactylus curved slightly upwards. Posterior border of merus, carpus, propodus of ambulatory legs lined sparsely with long stiff dark-colored setae.

Male abdomen elongated, telson distally rounded, sixth somite as long as broad, lateral borders of fifth conspicuously concave on proximal half, proximal margin much narrower; fourth somite broad, distal margin very convex (Fig. 2 b). G1 slender, curved dorsally, distal end rounded with inward-dorsal radiating brush of longer setae of approximately same length, and a row of short setae around the opening on the inner surface (Fig. 3 a–c).

Coloration. Grayish carapace, merus of external maxillipeds dark or with random blotches, chelipeds gray with pale palm and fingers, ambulatory legs banded dark and light gray (Fig. 4 a, b) (also see Miyake 1983: Pl. 56(8); Minemizu 2000: 309).

Distribution. Japan (type locality), Korea (Kamita 1941; Kim 1973) and North China (Shen 1932).

Remarks. Scopimera globosa is a common species on muddy and sandy shores in Honshu, Japan (Sakai 1939, 1976). Sketch of G1 of S. globosa De Haan, 1835 lectotype matches the present material collected from Honshu, Japan. However, of the over 300 Scopimera specimens collected and observed from more than four localities from Hong Kong (in South China) and more than six localities from Taiwan, no S. globosa was found. Shen (1940) reported S. globosa from Tsuen Wan, Wong Chuk Hang, and Tai Po in Hong Kong, but the first two sites are today already heavily urbanized and almost devoid of any natural coasts. Morton & Morton (1983: 185) stated “ Scopimera globosa is as common at Tai Tam as S. intermedia is at Shiu Hau…”. The second author visited both Tai Po and Tai Tam, and specimens from Tai Po are S. intermedia while no Scopimera sp. was found in Tai Tam, where a reservoir has been constructed. It is thus unclear whether S. globosa really exists in Hong Kong. As for Taiwanese records of S. globosa, the first was reported from Danshuei (= Tamsui), Taipei County, by Takahasi (1934) and have been recorded on numerous localities on the main island and Penghu. In a review of ocypodoid crabs, however, a typical S. intermedia G1 was illustrated under the name S. globosa (see Huang et al. 1992: fig. 16). Checking available specimens in National Taiwan Museum and National Museum of Natural Science which has been collected and named as S. globosa between 1980s and today, we could find no specimens referable to S. globosa. All this material has proven to be S. intermedia instead. Thus the presence of S. globosa in Taiwan and Hong Kong is not verified in this study and its southern limit along the Chinese coast remains unclear. However, our extensive collections in Taiwan and Hong Kong fail to yield any S. globosa, suggesting this species is probably absent in these two regions. There was one record of “ S. globosa ” from Singapore (Tan & Ng 1994) which may be misidentified with S. intermedia or other unrecorded species.