Glyptothorax dakpathari Tilak & Husain, 1976

Glyptothorax dakpathari Tilak & Husain, 1976 View in CoL

( Fig. 10 View FIGURE 10 )

Material examined. ZSI/NRC V-988 (1), 116.8 mm SL, holotype; ZSI/NRC V-989 (2), 103.2–110.0 mm SL, paratypes; India: Uttarakhand, Yamuna River below Dakpathar barrage , Dehradun District, India .

Diagnosis. Glyptothorax dakpathari can be distinguished from all Gangetic congeners except G. pectinopterus , G. brevipinnis , G. conirostris , G. bhurainu and G. himalaicus in the presence (vs. absence) of plicate ventral surface of pectoral-fin spine and first pelvic-fin ray ( Fig. 3e & f View FIGURE 3 ). It differs from both G. brevipinnis and G. pectinopterus in possessing serrated (vs. smooth) posterior margin of dorsal-fin spine, longer thoracic adhesive apparatus reaching (vs. not reaching) posterior limit of pectoral-fin base, and shorter adipose-fin base (9.5–11.9% SL vs. 13.9–18.0). It can be differentiated from G. conirostris in having thoracic adhesive apparatus completely encinctured by striae (vs. open caudally), absence (vs. presence) of medial pit and absence (vs. presence) of anteromedial striae on the thoracic adhesive apparatus ( Fig. 4c View FIGURE 4 ).

Glyptothorax dakpathari further differs from G. telchitta and G. botius in having a deeper body (depth at anus 15.1–18.1% SL vs. 9.9–13.3) and deeper caudal peduncle (8.4–8.8% SL vs. 3.1–5.9); from G. cavia and G. indicus in having a shorter head (20.7–23.1% SL vs. 27.6–29.9), and longer caudal peduncle (21.0–22.5% SL vs. 16.3–19.1); from G. garhwali in possessing serrated (vs. smooth) posterior margin of dorsal-fin spine and thoracic adhesive apparatus completely encinctured by striae (vs. open caudally); and from G. gracilis in having a thoracic adhesive apparatus with ovoid (vs. elliptic) central depression, and larger eye (12.2–14.4% HL vs. 9.4–10.8).

Description. Morphometric data in Table 3 View TABLE 3 . Head depressed; body subcylindrical. Dorsal profile rising evenly from tip of snout to origin of dorsal fin, then sloping gently ventrally from origin of dorsal fin to end of caudal peduncle. Ventral profile straight to anal-fin base, then sloping gently dorsally from anal-fin base to end of caudal peduncle. Anus and urogenital openings located at vertical through middle of adpressed pelvic fin. Skin tuberculate. Lateral line complete and midlateral.

Head depressed and narrow, rounded when viewed laterally. Snout prominent and rounded when viewed dorsally. Anterior and posterior nares large and separated only by base of nasal barbel. Gill opening broad, extending from immediately ventral to post-temporal to isthmus. Bony elements of dorsal surface of head covered with thick, tuberculate skin. Eye rounded, located entirely on dorsal half of head. Barbels in four pairs. Maxillary barbel long and slender, extending to middle of pectoral-fin base. Nasal barbel slender, extending to anterior orbital margin. Inner mandibular barbel extending to pectoral-fin base and outer mandibular barbel extending to middle of pectoral-fin base. Mouth inferior, lips papillate, premaxillary tooth band partially almost wholly exposed when mouth closed. Oral teeth small and villiform. Premaxillary teeth in single broad semi-lunate band. Dentary teeth in two narrow crescent-shaped bands separated at midline.

Thoracic adhesive apparatus consisting of striae in ovate field ( Fig. 4c View FIGURE 4 ) extending from isthmus to beyond posterior limit of pectoral-fin base. Striae uninterrupted, anteromedial striae absent. Medial pit absent. Dorsal fin located above anterior third of body, with I,5* (2) or I,6 (2) rays; fin margin gently concave; spine short and gently curved, anterior margin smooth, posterior with 6–9 serrations. Adipose fin with anterior margin and posterior margins straight. Caudal fin strongly forked. Procurrent rays symmetrical and extending slightly anterior to finbase. Anal-fin base ventral to adipose-fin origin. Anal fin with straight anterior margin and straight or slightly concave posterior margin; with ii,7 (1) or ii,8* (2) rays. Pelvic-fin origin immediately posterior to vertical through posterior end of dorsal-fin base. Pelvic fin with slightly convex margin and i,5 (1) or i,6* (2) rays; tip of adpressed fin reaching anal-fin origin. Pectoral fin with I,10* (3); pectoral spine broad and covered with thick skin. Anterior spine margin smooth, posterior margin with 11–14 serrations. Ventral surface of pectoral-fin spine and first pelvic-fin ray with plicae ( Figure 3e & f View FIGURE 3 ).

Colouration. In 70% ethanol: dorsal and lateral surface of head and body brown, fading to beige on ventral surface. All fins brown, with brown rays; outer rays darker than inner rays. Base of dorsal, adipose and caudal fins with pale black marking. Maxillary and nasal barbels brown dorsally, beige ventrally. Mandibular barbels beige.

Distribution. Glyptothorax dakpathari is currently known only from the type locality, the Yamuna River below Dakpathar Barrage in Dehradun District, Uttarakhand, India ( Fig. 7 View FIGURE 7 ). The Yamuna is a major tributary of the Ganges River in northern India.