Gammarus jaspidus Hou & Li, 2004, new species
Creators: name: Hou, Zhong-E
name: Li, Shuqiang
Publisher: name: Zenodo
Year: 2004
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Gammaridae
Gammarus
Gammarus jaspidus

description: Gammarus jaspidus, new species   
(Figs. 6-11)  
 Material examined. – Holotype - male, 11.5 mm (IZCAS-I-A0067), altitude 4500 m, the Lake YamzhoYumco (about 8 km away from Yarlung Zangbo River), (28.8 oN, 91.0 oE), Nagarze County, 28 Aug.2001.   
Paratypes - 4 males, 3 females, 3 juveniles (IZCAS), 2 males, 1 female (ZRC), same data as holotype.  
 Diagnosis. – Pleonites: pleonites 1-3 weakly elevated. Urosomites: urosomites 1 and 2 with laterally compressed, dorsal elevations, bearing 3-3-1 and 2-2-2 spines on dorsal margin, respectively.   
 Description. – Holotype, 11.5 mm. Head (Fig. 6A): cephalic lateral lobe truncate, inferior antennal sinus distinct, eyes subreniform. Antenna 1 (Fig. 6D): peduncular articles 1-3 in length ratio 1: 0.59: 0.34, with distal setae; flagellum with 24 articles, most articles with aesthetascs; accessory flagellum with 3 articles, article 3 small. Antenna 2 (Figs. 9D, E): peduncular article 4 about as long as article 5, both with 3 clusters of short setae along both margins; flagellum with 12 articles, some articles with calceoli.   
Upper lip (Fig. 6E) subrounded, with minute setae. Mandibles (Figs. 6F, G): left incisor 5-dentate, lacinia mobilis with 4 dentitions, molar triturative, article 2 of palp with 12 setae, length of article 3 about 73% of article 2, with 4 A-setae on inner face, 4 B-setae on outer face, a row of D-setae and 5 E-setae; right incisor 4-dentate, lacinia mobilis bifurcate, molar triturative, with 1 seta. Lower lip (Fig. 6I): inner plate lacking. Maxilla 1 (Figs. 6J, K): inner plate with 17 plumose setae, article 2 of left palp broad, with 8 slender spines and 2 stiff setae; article 2 of right palp broader, with 5 blunt spines and 2 stiff setae. Maxilla 2 (Fig. 6L): inner plate with a row of 27 plumose setae on inner face; outer plate broad, with apical setae. Maxilliped (Fig. 6H): inner plate with 3 apical spines and 1 subapical spine, outer plate with 10 slender spines on medial margin and 4 pectinate setae apically, article 4 of palp slender.  
Coxal plates: coxal plates of pereopods 1-3 subrectangular (Figs. 7A, B, 8D), with 1-3 setae on anterior corner and 1 seta on posterior corner; coxal plate 4 excavated (Fig. 8E), with 1 anterior seta and 4 setae on posterior margin; coxal plates 5 and 6 (Figs. 8A, B): anterior lobes small, posterior lobe with 2-3 short setae on posterior corners; coxal plate 7 (Fig. 8C) with 4 setae on posterior corner.  
Gnathopod 1 (Figs. 7A, E): basis with long setae on anterior and posterior margins, and 5 spinulate setae on distal margin; carpus triangular, about 70% of propodus in length; propodus pyriform, palm oblique, bearing 1 median palmar spine, with 10 spines on posterior margin and 6 facial spines; dactylus with 1 seta on outer margin. Gnathopod 2 (Figs. 7B, F): carpus about 70% of propodus in length, parallel-sided; palm of propodus with 1 median spine and 6 spines on posterior corner; dactylus fitting with palm margin of propodus.  
Pereopod 3 (Figs. 8D, F): pereopod 3 with long straight setae on posterior margin; articles 5 and 6 accompanied by several spines on posterior margin; dactylus slender, with 1 seta on outer margin and 2 setae at joint of nail. Pereopod 4 (Figs. 8E, G): shorter than pereopod 3, posterior margin with long straight setae.  
Pereopods 5-7 (Figs. 8 A-C, H, I): pereopods 6 and 7 longer than pereopod 5, anterior margin of bases of pereopods 5-7 slightly convex, with 5 short spines and several setae proximally, posterior margin nearly straight in pereopod 5, weakly sinusoid in pereopods 6 and 7, with a row of 12 short setae, inner face of bases of pereopods 6 and 7 with a few short setae; articles 4-6 with groups of spines on anterior margin, without long setae; dactylus slender, with 1 seta on outer margin and 2 setae at joint of nail.  
Coxal gills (Figs. 7B, 8B, C, E): coxal gills of pereopods 2- 7 ovate.  
Pleonites (Fig. 6B): weakly elevated, with several short setae on dorsal margins. Epimeral plates: epimeral plates 1-3 with progressively acuminate posterior corners, with a few short setae on posterior margin; epimeral plate 1 ventrally rounded, with 6 setae on anterior corner; epimeral plate 2 with 5 spines on ventral margin; epimeral plate 3 with 3 spines on ventral margin. Pleopods (Figs. 7C, 9A, B): subequal in length, peduncle with some long setae, 2-3 retinacula accompanied by 1-3 setae; rami with about 22 articles, fringed with plumose setae.  
Urosomites (Figs. 6B, C): urosomites 1 and 2 with laterally compressed, dorsal elevations, bearing 3-3-1 and 2-2-2 spines on dorsal margin, respectively; urosomite 3 with 2 spines on dorsal margin. Uropod 1 (Fig. 9C): both rami subequal. Uropod 2 (Fig. 9F): peduncle with 1-1 and 1-1-1 spines on outer and inner margins, respectively; outer ramus a little shorter than inner ramus. Uropod 3 (Fig. 9G): peduncle with 3 distal spines; rami slender; length of inner ramus about 70% of article 1 of outer ramus, with 1 lateral spine; article 1 of outer ramus with 1-1-2-2 lateral spines and 2 distal spines, article 2 stout; both rami armed with plumose setae.  
Telson cleft (Fig. 7D), each lobe with 2 distal spines accompanied by 5 setae, 1 basolateral spine and 2-3 clusters of facial setae.  
 Female. – Body length 8.5 mm, ovigerous, with more than 20 eggs. Gnathopod 1 (Figs. 10B, D): with long setae on posterior margin, carpus a little shorter than propodus, propodus not as oblique as in male, with 8 spines on posterior margin, dactylus with 1 seta on outer margin. Gnathopod 2 (Figs. 10A, C, E): larger than gnathopod 1, propodus subrectangular, with 3 spines on posterior corner. Uropod 3 (Figs. 11D): stout, length of inner ramus about 90% of article 1 of outer ramus, both rami ornamented with plumose setae. Oostegites: oostegites in pereopods 2-5 broad or elongate (Figs. 10C, 11H, I, A), with many marginal setae.   
 Etymology. – From the Tibetan language, “YamzhoYumco” meaning jade-colored and changing into Latin “jaspidus ”.   
  Remarks. – Gammarus jaspidus  belongs to G. pulex -group. Gammarus jaspidus is similar to G. lacustris Sars, 1863 in (1) the shape of the gnathopods, (2) the armature of the pereopods 3 and 4, (3) the ratio of the inner and outer ramus of uropod 3. Gammarus jaspidus differs from G. lacustris in (1) the urosomites 1 and 2, which laterally compressed and dorsally elevated, (2) the epimeral plates 2 and 3 not very acute, and (3) the telson with 1 basolateral spine and 3 groups of facial setae.   
 Gammarus jaspidus differs from G. lasaensis in the relatively slender body (stout in G. lasaensis) and the palm of propodus of gnathopods 1 and 2 without extra spines except for a main middle spine (G. lasaensis with 2 and 3 median palmar spines on the gnathopods 1 and 2, relatively).   
 Distribution. – Nagarze, Tibet, China (present study).
description: Published as part of Hou, Zhong-E & Li, Shuqiang, 2004, Gammarus Species From Tibet Plateau, China (Crustacea: Amphipoda: Gammaridae), pp. 147-170 in Raffles Bulletin of Zoology 52 (1) on pages 154-161, DOI: 10.5281/zenodo.13244319