Ericthonius pugnax Dana

Appadoo, C & Myers, A. A., 2004, Corophiidea (Crustacea: Amphipoda) from Mauritius, Records of the Australian Museum 56 (3), pp. 331-362 : 357

Ericthonius pugnax Dana

Erichthonius [sic] pugnax Dana, 1852a: 213 .

Ericthonius pugnax .— Stebbing, 1906: 672.— Pirlot, 1938: 352.— Nagata, 1960: 179, pl. 17.— Nagata, 1965: 320, fig. 40.— Ledoyer, 1969: 179, fig. 1.— Ledoyer, 1986: 628, fig. 239.— Myers, 1995: 80, figs. 40–42.

Erichthonius [sic] macrodactylus Dana, 1852a: 218 .

Pyctilus pugnax Dana, 1852b: 975 , pl. 67, fig. 4a–d.

Pyctilus macrodactylus Dana, 1852b: 974 , pl. 67, fig. 3a–c.

Material examined. 13, AC, from Sargassum sp. , La Cuvette (20°00'S 57°34.2'E), 14 May 1998 .

Diagnosis. Alcohol preserved specimen cream-coloured. A flap-like sternal process is present on pereon segment 1. Gnathopod 1 basis slender, 2.5× as long as broad, posterior margin smooth. Gnathopod 2 coxa shallow, sub-triangular, 1.8× as broad as long, with stridulating ridges on the ventral margin; carpus anterior margin slightly convex with two distal teeth, the outer one longer, distal margin slightly deflected; propodus 0.8× carpus, posterior margin sinuous with slender setae; dactylus large, with a few setae on anterior margin and a group of apical setae. Pereopod 3–4 basis distally expanded. Pereopod 5 basis posterodistal margin produced into a lobe reaching to end of ischium, and bearing a few setae.

Type locality. Sulu Sea

Distribution. Indo-west Pacific

Habitat. This species was rare in the substrata sampled in this study and was collected at depths of less than 1 m at La Cuvette, in the north coast.

Remarks. This is the first record of the species from Mauritius. Ericthonius pugnax males are easily distinguished by the shape of the basis of the pereopod 5, which is strongly produced into a lobe on the posterodistal margin. The shape of the gnathopod 2 in the current material agrees with the description of Ledoyer 1986 (631, fig. 239) and Myers 1995 (78, fig. 40). No additional material is available here to show variation of the gnathopod 2 in much larger specimens as observed by Myers (1995).