Ericthonius punctatus (Bate)

Appadoo, C & Myers, A. A., 2004, Corophiidea (Crustacea: Amphipoda) from Mauritius, Records of the Australian Museum 56 (3), pp. 331-362 : 359-360

Ericthonius punctatus (Bate)

Figs. 21–22

Podocerus punctatus Bate, 1857: 148 . Dercothoe punctatus Bate, 1862: 260 .—Bate & Westwood, 1863:

461 (with un-numbered figure). Ericthonius punctatus .— Myers 1982: 202, fig. 138.—Myers &

McGrath, 1984: 285, figs. 3–4. Ericthonius abditus Sars 1894: 602 , pl. 215. Erichthonius brasiliensis .—Chevreux & Fage, 1925: 353, fig. 360. Ericthonius brasiliensis .— Schellenberg 1942: 212, fig. 173.—

Gurjanova 1951: 948, fig. 659.— Lincoln, 1979; 560, figs.

268a–f, 269a–e.— Ledoyer, 1986: 624, fig. 237A.

Material examined. 233, AM P60863, from Padina sp. La Cuvette (20°00'S 57°34.2'E), 14 May 1998; 333, 1♀, AM P60864, from Hypnea sp. , Amphiroa sp. , Caulerpa sertulariodes, Tamarin (20°19.5'S 57°22'E), 18 June 1999.

Diagnosis. Body (in alcohol) with mottled-brown pigment concentrated on head, pereon and coxae. Pereon segment 1 with flap-like sternal process. Gnathopod 2 coxa moderately deep, with parallel lateral margins, ventral margin round and with stridulating ridges; basis lageniform, 3.2× as long as broad; carpus anterior margin strongly convex proximally, carpal processes on posterior margin deflected, with twoteeth separated from each other by a semi-elliptical depression; propodus 0.8× length of carpus, inner margin weakly sinuous; dactylus stout with short setae on inner and outer margins and long terminal setae. Pereopod 3–4 basis widest distally, anterior margin evenly convex.

Female gnathopod 1 coxa subround. Gnathopod 2, coxa moderately deep; carpus posterior margin produced into a lobe bearing robust setae and slender setae; propodus tapered at distal end, 2× length of carpus, palmar margin oblique with two stout robust proximal setae.

Type locality. Oxwich Bay , Glamorgan, Wales

Distribution. Norway to tropical West Africa, including the British Isles, Madagascar, Mauritius.

Habitat. Ericthonius punctatus was collected at depths of less than 1 m from sites in the west, north and east coasts of the island. It was more common in the north coasts at sites such as Grand Baie, la Cuvette and Bain Boeuf. It is lives mostly amongst the brown algae, Sargassum sp.

Remarks. This is the first record of the species from The Indian Ocean. It can be distinguished from E. brasiliensis by the pattern of pigmentation on the body surface and the lack of the knob-like process on the basis of the male gnathopod 1. It can be distinguished from E. pugnax , by the shape of the coxa 2 of the male, which is much more shallow in E. pugnax , the shape of the basis of the pereopod 5 and the strongly divergent teeth of the male gnathopod 2 carpus.

Because this species seems an unlikely occurrence in the tropical Indian Ocean, figures are provided here for comparative purposes. The possibility of introduction cannot be ruled out.

ACKNOWLEDGMENTS. We are grateful to the University of Mauritius and the Tertiary Education Commission for their support in carrying out the current study. We are also deeply indebted to Prof. I. Fagoonee for his support in carrying out this study. Thanks also due to University of Mauritius (Higher Technical Education Plan) for fully sponsoring visits of one of us (C.A.) to University College Cork, Ireland. We thank Prof. J. Davenport and the staff of the Department of Zoology at University College Cork, for their hospitality and support.