Ericthonius brasiliensis (Dana)

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

Ericthonius brasiliensis (Dana)

Pyctilus brasiliensis Dana, 1852b: 976 , fig. 5a–h. Ericthonius brasiliensis Bousfield, 1973: 175 , pl. 59, fig. 2.—

Myers, 1982: 200, figs. 136–137.—Myers & McGrath 1984:

382, fig. 1–2.—Appadoo & Steele 1998: 640. Not Ericthonius brasiliensis Ledoyer 1986: 624 , fig. 237A.

Material examined. 13, AM P60862, from mixture of Sargassum sp. , Amphiroa sp. , Pocockiella variegata and Cymodocea sp. , Bain Boeuf, 16 June 1999; 13, AC, from Acanthophora spicifera, Anse la Raie (19°59.5'S 57°37.5'E), 15 May 1998. 13, 1♀, AC, from Sargassum binderi, Bain Boeuf (19°59'S 57°36'E), 16 June 1998.

Diagnosis. Body (in alcohol) with brown speckled pigmentation on head, coxae, pleon and urosome. Pereon segment 1 with a forward produced sternal process. Gnathopod 1 basis 2× as long as broad, posterior margin with a distinct knob-like process. Gnathopod 2 coxa deep, ventral margin rounded, with stridulations and a small group of setae; carpus 1.8× as long as broad anterior and posterior margins parallel, posterodistal margin with two teeth, the outer one longer, separated by a V-shaped incision. Pereopod 3–4 basis 1.5× as long as broad, widest medially.

Female gnathopod 1 basis slender; propodus palm oblique. Gnathopod 2 coxa deep; carpus posterior margin produced into a lobe with two robust setae and long slender setae; propodus tapered distally, slightly more than twice length of carpus, palm oblique with two robust setae.

Variation. In some males, the eyes are smaller and do not completely fill the eye-lobe.

Type locality. Rio de Janeiro

Habitat. Ericthonius brasiliensis was collected at depths of less than 1 m mostly from the north coasts. It was collected amongst brown algae and was more common at Bain Boeuf, a site with very little wave-action and large amounts of suspended sand.

Distribution. Venezuela, Brazil, West Indies, New England and the Mediterranean Sea, Mauritius.

Remarks. The material recorded from Mauritius agrees very well with the description given by Myers & McGrath (1984) of material from the type locality. Among a few differences are the large eye in the current material, pereopods 3 and 4 being widest medially and the weak setation of the propodus of the male gnathopod 2. The deep coxa 2 and the knoblike process on the basis of the gnathopod 1 in males are distinctive features of this species (Myers & McGrath, 1984). These two characters can also be used to distinguish the males of this species from the other species of the genus, E. latimanus , E. pugnax and E. punctatus , reported from the island.