Ethusa granulosa Ihle, 1916

Castro, Peter, 2005, Crabs of the subfamily Ethusinae Guinot, 1977 (Crustacea, Decapoda, Brachyura, Dorippidae) of the Indo-West Pacific region, Zoosystema 27 (3), pp. 499-600 : 522-523

Ethusa granulosa Ihle, 1916

( Fig. 33A )

Ethusa granulosa Ihle, 1916b: 143 , 151 (list), 152 (list), 153 (list), 156 (list), fig. 76. — Serène 1968: 40 (list). — Serène & Lohavanijaya 1973: 34 (key). — Chen 1993: 318 (key), 323, fig. 5; 2000: 426. — Nagai 1995: 61, pl. 1, fig. 10. — Marumura & Kosaka 2003: 23.

TYPE MATERIAL. — Lectotype: ovig. cl 7.2 mm, cw 7.4 mm, Siboga , stn 59 ( ZMA Crust.De 102976); paralectotypes: cl 7.2 mm, cw 7.1 mm,

cl 7.0 mm, cw 7.0 mm, cl 6.6 mm, cw 6.8 mm, same location ( ZMA Crust.De 102977).

Ihle (1916b) based his description on four female specimens without selecting a holotype. One of the four syntypes, the largest female, is hereby designated the lectotype and the remaining three females are the paralectotypes. One of the paralectotypes was illustrat- ed by Ihle (1916b: fig. 76).

TYPE LOCALITY. — Indonesia, Lesser Sunda Islands, Savu Sea north of Roti island, 10°22.7’S, 123°16.5’E, 390 m.

MATERIAL EXAMINED. — Japan. Honshu, Sagami Bay, 5 km SW of Yoga Shima, 300 m, Hatagumo, T. Sakai and Emperor Hirohito coll., 3.III.1964, 1 ovig.

( SMF 28934). — Kii Peninsula, off Sabiura, 90 m, S. Yamaguchi coll., 24.VI.1979, 1 ( CBM-ZC 4391). — Kii Peninsula, off Shiono Misaki, 300 m, S. Nagai coll., X.1996, 1 ( CBM-ZC 3567). — Kii Peninsula, W of Shiono Misaki, 33°25.70’N, 135°40.50’E, 250 m, S. Nagai coll., 30.I.1998, 1 ( CBM-ZC 5707).

Indonesia. Lesser Sunda Islands, Siboga , stn 59, Savu Sea, N of Roti island, 10°22.7’S, 123°16.5’E, 390 m, M. Weber coll., 26.IV.1899, 1 ovig. lectotype ( ZMA Crust.De 102976).

Moluccas, Siboga , stn 153, Halmahera Sea, N of Kofiau island, 00°59.1’S, 129°48. 8’E, 411 m, M. Weber coll., 16.VIII.1899, 3 paralectotypes ( ZMA Crust.De 102977).

Solomon Islands. SALOMON 1, stn CP 1783, 08°32.8’S, 160°41.7’E, 399-700 m, 29.IX.2001, 1 juv. cl 9.5 mm, cw 8.9 mm ( MNHN-B 28704).

Vanuatu. MUSORSTOM 8, stn DW 1045, 16°54.50’S, 168°20.37’E, 488- 459 m, 30.IX.1994, 1 ( MNHN-B 27497). — Stn DW 1061, 16°14.54’S, 167°20.12’E, 458-512 m, 2.X.1994, 1 ( MNHN-B 28698).

New Caledonia. BATHUS 3, stn DW 793, 23°47.50’S, 169°48.75’E, 731-751 m, 26.XI.1993, 1 undet. sex ( MNHN-B 28496).

BATHUS 4, stn CP 910, 18°59.32’S, 163°08.47’E, 560-608 m, 5.VIII.1994, 4, 1 juv., 2 ( MNHN-B 28498). — Stn CP 911, 18°57.80’S, 163°08.47’E, 566- 558 m, 5.VIII. 1994, 3 ( MNHN-B 28499). — Stn CP 921, 18°46.72’S, 163°17.01’E, 613- 610 m, 6.VIII.1994, 1 juv.

( MNHN-B 28500).

Wallis and Futuna Islands. MUSORSTOM 7, stn DW 556, 11°49’S, 178°18’W, 440 m, 19.V.1992, 1, 1 ( MNHN-B 28496).

DISTRIBUTION. — Japan ( Nagai 1995; Marumura & Kosaka 2003), Indonesia (Lesser Sunda Islands, Moluccas) ( Ihle 1916b), Vanuatu ( Chen 2000), New Caledonia ( Chen 1993), and now from the Solomon and Wallis and Futuna Is. Depth: 90-751 m ( Fig. 34 ). SIZE. — Maximum size: cl 8.9 mm, cw 8.4 mm ( MNHN-B 28498), cl 14.7 mm, cw 14.6 mm ( MNHN-B 28698).

REMARKS

Characteristic of Ethusa granulosa is a carapace that is as broad as long ( Ihle 1916b: fig. 76; Chen 1993: fig. 5a), with nearly straight lateral borders that diverge toward the posterior border, and covered by small, dense granules. The anterior border of the endostome just reaches the posteri- or border of the antennular fossae of the basal antennular articles. The G1 are stout with an attenuated distal end.

A specimen from the Solomon Is (juvenile, cl 9.5 mm, cw 8.9 mm, MNHN-B 28704) agrees with the diagnostic characters of E. granulosa but the granules on the carapace are not as dense as in the more typical specimens. The anterior border of the endostome unusually extended beyond the antennular fossae in a dry specimen from Japan (ovig. cl 10.5 mm, cw 10.1 mm; SMF 28934). Ethusa granulosa is very close to E. orientalis Miers, 1886 , and E. magnipalmata Chen, 1993 . The outer orbital teeth are more elongated and acute than in E. orientalis , which are typically triangular. The most significant difference between the three species is the shape of their G1, which makes the identification of females a difficult task.

Ethusinae of Indo-West Pacific ( Crustacea, Brachyura , Dorippidae )

Figures

FIG. 33. — A, Ethusa granulosa Ihle, 1916, cl 14.7 mm, cw 14.6 mm, Vanuatu, west coast of Malekula, MUSORSTOM 8, stn DW 1061, 458-512 m (MNHN-B 28698) (photograph by J.-L. Menou, IRD, Nouméa); B, Ethusa hawaiiensis Rathbun, 1906, cl 6.7 mm, cw 6.2 mm, Vanuatu, S of Anatom, MUSORSTOM 8, stn CP 963, 400-440 m (MNHN-B 28538) (photograph by J.-L. Menou, IRD, Nouméa); C, Ethusa indica Alcock, 1894, cl 7.8 mm, cw 7.8 mm, Vanuatu, SE of Éfaté, MUSORSTOM 8, stn CP 1036, 920-950 m (MNHN-B 28560) (photograph by J.-L. Menou, IRD, Nouméa); D, Ethusina challengeri (Miers, 1886), cl 25.9 mm, Mid-Indian Basin, SAFARI 2, stn 35, trawl CP 29, 4950-4928 m (MNHN-B 28697) (photograph by P. Briand, IFREMER); E, Ethusina macrospina Ng & Ho, 2003, cl 10.4 mm, cw 11.0 mm, Taiwan, off southwest coast, TAIWAN 2003, stn CD 203, 635-868 m (NTOU) (photograph by T.-Y. Chan, NTOU).

FIG. 34. — Bathymetric distribution of Indo-West Pacific ethusine crabs.