Gammarus Fabricius, 1775

Hou, Zhong-E & Li, Shuqiang, 2004, Gammarus Species From Tibet Plateau, China (Crustacea: Amphipoda: Gammaridae), Raffles Bulletin of Zoology 52 (1), pp. 147-170 : 147-148

Gammarus Fabricius, 1775

Diagnosis. – Antenna 1: primary flagellum longer than peduncle, accessory flagellum with more than 2 articles.

Map 1. Localities of freshwater amphipods from Tibet. Circle = Gammarus frigidus , new species; triangle = G. sinuolatus , new species; square = G. jaspidus , new species; pentangle = G. lasaensis Barnard & Dai, 1988 .

Antenna 2: shorter than antenna 1, flagellum with or without calceoli. Maxilla 1: left and right palps asymmetric. Maxilla 2: inner plate with a diagonal row of plumose setae. Gnathopods 1 and 2: palm of gnathopod 1 more oblique than palm of gnathopod 2, palms with one or more median spines. Uropod 1: peduncle with 1 basofacial spine. Telson: deeply cleft. Coxal gills: present in pereopods 2-7.

Species Composition. – Gammarus is represented by about 130 species worldwide now. Barnard & Barnard (1983) reviewed the freshwater Amphipoda worldwide and 117 species were listed under the genus Gammarus . After 1983, more than 20 species have been reported by several authors (Karaman & Pinkster, 1987; Barnard & Dai, 1988; Morino & Whitman, 1995; Stock et al., 1998; Hou & Li, 2002a, b, 2003a, b, c, d; Hou, Li & Zheng, 2002; Hou, Li & Morino, 2002; Hou, Li & Koenemann, 2002). Because the genus Gammarus is based on specimens collected from limited areas of the world, it is expected that the genus Gammarus will overrun 200 species.