Ethusa quadrata Sakai 1937
Creators: name: Castro, Peter
Publisher: name: Zenodo
Year: 2005
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Ethusidae
Ethusa
Ethusa quadrata

description: Ethusa quadrata Sakai, 1937   
 Ethusa quadrata Sakai, 1937: 76 (key), 78, figs 1c, 3; 1956: 7 (list), fig. 8.6; 1965: 24, pl. 12, fig. 3 (colour); 1976: 65, figs 26c, 28, pl. 23, fig. 3 (colour). — Serène 1968: 40 (list). — Takeda & Miyake 1970: 209; 1972: 68. — Serène & Lohavanijaya 1973: 35 (key). — Miyake 1983: 18, 198, pl. 6, fig. 4 (colour). — Serène & Vadon 1981: 120, 121. — Chen 1985: 191, fig. 10, pl. 1, fig. 7; 1986: 129, fig. 11; 1993: 318 (key), 319 (list). — Nagai 1995: 60, pl. 1, fig. 7. — Muraoka 1998: 17. — Takeda 2001: 225, 254, 259. — Chen & Sun 2002: 54, 241, fig. 102. — Komai et al. 2002: 20. — Marumura & Kosaka 2003: 23.   
TYPE MATERIAL. — Holotype:, Japan, Honshu, Sagami Bay, between Ito and Hatsu Shima, Misago, stn 10, 80 m, VI.1934. Deposit unknown.  
TYPE LOCALITY. — Japan, Honshu, Sagami Bay, between Ito and Hatsu Shima, 80 m.  
 MATERIAL EXAMINED. — Japan. Honshu, Kii Peninsula, W of Shionomisaki, 130 m, S. Nagai coll., VI.1998, 1 (CBM-ZC 5026). — Sagami Bay, Kameki reef, 120 m, T. Sakai and Emperor Hirohito coll., 19.VI.1964, undet. sex (SMF 28924).   
Izu Islands, Hyotan-se Bank, 34°20.93’N, 139°04.78’E, 160-200 m, T. Komai coll., 22.X.1996, 1 (CBM-ZC 4602).  
 Philippine Islands. South China Sea, MUSORSTOM 1, stn CP 62, 13°59.5’N, 120°15.6’E, 179-194 m, 27.III.1976, 1 (MNHN-B 18170).   
MUSORSTOM 2, stn CP 26, 13°49’N, 120°50’E, 299-320 m, 23.XI.1980, 1 (MNHN-B 18171).  
Bohol, Balicasag island, off Panglao island, tangle nets from local fishermen, 50-500 m, 28.XI.2001, 1 (ZRC 2001.0517).  
 New Caledonia. BATHUS 2, stn DW 717, 22°44.82’S, 167°16.58’E, 350-393 m, 11.V.1993, 1 (MNHN-B 28556).   
BATHUS 4, stn DW 895, 20°15.40’S, 163°51.70’E, 315-350 m, 3.VIII.1994, 1 (MNHN-B 28557).  
NORFOLK 1, stn DW 1679, 24°43’S, 168°10’E, 298-324 m, 22.VI.2001, 1 (MNHN-B 28558).  
DISTRIBUTION. — Japan (see Sakai 1976), East China Sea (Takeda & Miyake 1970; Chen 1986), Philippine Is (Serène & Vadon 1981; Chen 1985), and now from New Caledonia. Depth: 35 (Sakai 1965) - 393 m (Fig. 34). It was also collected from fishing nets at depths of 50- 500 m.  
SIZE. — Maximum size: cl 6.9 mm, cw 5.8 mm (MNHN-B 28556), cl 8.4 mm, cw 7.3 mm (MNHN-B 18171).  
REMARKS  
 Ethusa quadrata is easily identified by the rectangular, nearly-square appearance of its carapace, with the sides straight and nearly parallel to each other (Sakai 1937: fig. 3; 1965: pl. 12, fig. 5; 1976: fig. 28; Miyake 1983: pl. 6, fig. 4; Chen 1985: fig. 10; Chen & Sun 2002: fig. 102.1). The orbital sinuses are L-shaped, thus reinforcing the square appearance. Differences from E. furca Chen, 1993, and E. hawaiiensis Rathbun, 1906, which also have rectangular carapaces, are given in the respective discussions of these two species (see above).   
Sakai (1937: 80) mentioned that “the animal is protected by a piece of bivalves”.
description: Published as part of Castro, Peter, 2005, Crabs of the subfamily Ethusinae Guinot, 1977 (Crustacea, Decapoda, Brachyura, Dorippidae) of the Indo-West Pacific region, pp. 499-600 in Zoosystema 27 (3) on pages 542-543, DOI: 10.5281/zenodo.5399909