Schistura greenei, Endruweit, Marco, 2017

Endruweit, Marco, 2017, A new Schistura from the Salween basin in western Yunnan (Teleostei: Nemacheilidae), Zootaxa 4243 (2), pp. 394-400 : 395-396

Schistura greenei , new species

( Figs. 1 , 2 )

Holotype. KIZ 2014006034, 42.4 mm SL; China: Yunnan Prov.: Lincang Pref.: Cangyuan Cty.; Salween: Nangunhe River: Nanbanhe River ; 23°18.543' N, 98°57.322' E, elevation 1056 m; coll. Endruweit, M. & Qin, T., 22 Aug. 2014.

Paratypes. KIZ 2014006037-6039, 6041 , 4 specimens, 34.0– 38.8 mm SL; ZFMK-ICH 103631-3634, 4, 33.2–44.5 mm SL; data as for holotype.

Diagnosis. Schistura greenei is distinguished from its congeners within the Salween and neighboring drainages by the following combination of characters: complete lateral line; 8+7 branched caudal-fin rays; 8–9 [8] pectoral-fin rays; 7–8 [7] pelvic-fin rays; 38 vertebrae; lower jaw not notched; HL 19–20% SL, head depth at eye 39–47% HL; head depth at nape 47–52% HL; maximum head width 59–69% HL; caudal peduncle depth 39–49% HL; caudal peduncle length 66– 79% HL; body depth 54–67% HL; prepelvic length 50–51% SL; pre-anus length 69–74% SL; 17–21 bars, predorsally inconspicuous; and a broad brown stripe along dorsal midline of the caudal peduncle.

Description. See Figure 1 for general appearance and Table 1 for morphometric data. Body predorsally cylindrical, postdorsally laterally compressed; elongate, depth 7.1–8.9 times in SL. Maximum body depth about midway between origins of pectoral and dorsal fins. Caudal peduncle shallow, depth 1.5–1.9 times in its length. Axillary pelvic lobe present, posteriorly free. Anus located 1.0–2.2 times eye diameter in front of anal-fin origin. Snout blunt. Cheeks not inflated. Head width constantly increasing from nostril to about edge of preoperculum. Eye large; located dorsolaterally, not reaching dorsal profile when viewed laterally. Interorbital space flat, narrow. Anterior nostril with a flap-like tube, not pierced, not reaching orbit. Suborbital lobe absent. Mouth ( Fig. 2 ) inferior, gape 1.4–1.8 times wider than long. Lips thick, furrowed, notched medially. Upper jaw with pointed processus dentiformis; lower jaw spoon-like, not notched. Medial rostral barbel failing to reach rictus, lateral reaching rictus. Maxillary barbel reaching vertical through anterior rim of orbit. Tubercles on top and side of head.

Vertebrae 38 (n=7); 19–20 [19] abdominal and 18–19 [19] caudal. Gas bladder in ossified capsule; dumbbellshaped; no secondary chamber. Gastrointestinal tract with simple, U-shaped stomach; intestines with single loop immediately after stomach. Largest recorded length 44.5 mm SL, 52.6 mm total length (ZFMK-ICH 103631).

Scales small, sparsely set on anterior part of body, deeply embedded in anterior of dorsal fin; abdomen in front of pelvic fin naked. Lateral line complete, reaching caudal-fin base, with 106–127 pores. Cephalic lateralis system with 7–8 supraorbital, 3+10–12 infraorbital, 9 preoperculo-mandibular and 3 supratemporal pores.

Dorsal fin with 4 simple and 7½–8½ [7½] branched rays; distal margin straight. Anal fin with 3 simple and 5½ branched rays; distal margin straight; not reaching caudal-fin base. Caudal fin emarginate, with 8+7 branched rays; lobes equal, rounded. Pelvic fin with 8–9 [8] rays, not reaching anus, inserted slightly anterior to dorsal-fin origin; fourth ray longest; distal margin convex. Pectoral fin with 8–9 [8] rays, not reaching midway to pelvic-fin origin; fifth ray longest; distal margin convex.

Coloration of preserved specimens. Body beige, dorsum darker, abdomen lighter, with 17–21 brown bars, equal to or wider as interspaces. Width and intensity of bars decreasing towards head. Predorsal bars narrow, very faint, often indiscernible, interconnected over dorsum; postdorsal bars broad, conspicuous, interconnected over ventral midline, widest at midlateral. A conspicuous, broad, brown stripe along dorsal midline behind dorsal fin; with 1–2 postdorsal bars adjacent to the dorsal-fin base narrowly connected. Usually residual postdorsal bars not reaching dorsal midline, sometimes reduced to blotches along midlateral. Bar at caudal-fin base inconspicuous, gray, dissociated into a small roundish mark on upper lobe and a somewhat larger, slant vertically extended mark reaching midlateral on lower lobe. Abdomen with numerous, densely set melanophores, sparse on isthmus. Head beige, top and upper part of operculum dark gray. Snout with dark gray mask running straight from origin of lateral rostral barbel along infraorbital cephalic lateralis canal. Dorsal fin with conspicuous, sub-basal, black spot on last simple and first branched ray with a medial, broad, transverse, dark gray band on light gray background. Caudal fin with 3–4 transverse, dark gray bands on light gray background. Other fins with a medial, broad, transverse, dark gray band on light gray background.

Distribution. Schistura greenei is known only from the type locality, the Nanbanhe River, a tributary to the Nangunhe River, Salween drainage ( Fig. 3 ).

Ecology. With an average width of about 8 m and depth of about 1 m at the collection site, the Nanbanhe River showed an elevated water level at the time of the visit. The slight turbidity and brownish coloration of the fast flowing water which had a pH of 6.2, and a conductivity of 100 µS/cm, are presumed to be caused by prolonged rain falls typical for late August in this region. The stream bottom consisted of sand, pebbles, twigs, rocks and boulders to which short green algae were attached. Co-occurring fish species were the nemacheilid loaches Schistura cryptofasciata , S. poculi and the sisorid catfish Oreoglanis immaculatus .

Etymology. Named after Richard Greene of the Smithsonian Institution, Washington, for his persistent support over many years. A patronym in apposition.

Figures

FIGURE 1. Schistura greenei, KIZ 2014006034, holotype, 42.4 mm SL; Yunnan: Cangyuan; Nanbanhe River.

FIGURE 2. Schistura greenei, KIZ 2014006039, paratype, 37.0 mm SL; head in ventral view.

FIGURE 3. Map of Sino-Burmese border region. Symbol indicates the type locality of Schistura greenei.