Barilius profundus, Dishma & Vishwanath, 2012

Dishma, M. & Vishwanath, W., 2012, Barilius profundus, a new cyprinid fish (Teleostei: Cyprinidae) from the Koladyne basin, India, Journal of Threatened Taxa 4 (2), pp. 2363-2369 : 2364-2366

Barilius profundus sp. nov.

( Image 1 )

Type material

Holotype: 24.xii.2009, 22023 ’N & 92057 ’E, 71.1mm SL; Koladyne River at Kolchaw, Lawntlai District, Mizoram, India, coll. Nebeshwar and party, MUMF 27001 .

Paratypes: 4 exs., 55.2–67.7 mm SL, data as for holotype, MUMF 27002-27005 ; 8 exs., 30.xi.2008, 50.9–69.9 mm SL; Koladyne River at Kolchaw, Lawntlai District, Mizoram, India, coll. Nebeshwar & party, MUMF 27021-27028 . One paratype ( MUMF 27005 , 54.5mm SL) dissected for osteology .

Diagnosis

A species of Barilius with the following combination of characters: great body depth at dorsal-fin origin (32.0–37.3 % SL); 17–18 pre-dorsal scales; 7–10 dark blue bars against faintly brown to yellowish-cream background of body, width of bar narrower than interspace width; lateral line complete with 30–32 + 2–3 scales; eye diameter (38.3–42.9 % HL), predorsal length (58.9–64.0 % SL); dorsal-fin length (21.6–25.7 % SL); ½7/1/2½ lateral transverse scales; 12 circumpeduncular scales; and 35 vertebrae.

Description

Morphometric data are shown in Table 1 and Appendix 1. Body compressed, abdomen rounded. Dorsal profile in front of dorsal-fin origin relatively straight, gently sloping downward towards base of caudal peduncle. Ventral profile slightly curved till pectoral-fin origin, then straight up to anal-fin origin, thereafter sloping dorsally to end of caudal peduncle. Muscular pads present at base of pectoral and pelvic fins.

Head moderately compressed; shorter than wide. Snout blunt, profile dorsally curved and rounded when viewed laterally, length shorter than interorbital distance. Eyes large, slightly bulging (convex), visible both from dorsal and ventral sides of head, situated in anterior half of head, diameter smaller than interorbital distance. Interorbital space slightly arched. Mouth terminal, obliquely directed upwards. Gape of mouth reaches anterior margin of orbit. Tubercles on snout and lower jaw poorly developed.

Barbels two pairs, short. One pair each of rostral and maxillary. Lips thin. Nostrils almost at level of upper margin of eye, distinctly nearer to anterior margin of eye than tip of snout. Jaws equal in length. Lower jaw without symphysial knob.

Dorsal fin inserted posterior to pelvic-fin origin with ii, 7½ rays and closer to caudal-fin base than tip of snout; longer than pelvic and anal fin; tip of last branched ray extending to middle of anal fin base. Pectoral fin with i,11 rays, shorter than head length; their tips pointed or nearly so; not reaching pelvic-fin origin. Pelvic fin with i, 8 rays, its origin much nearer to anal-fin origin than pectoral-fin origin, shorter than head length and pectoral fin; pelvic fin not reaching

anal opening. Anal-fin origin just below base of last dorsal fin ray, with ii, 10½ rays; not reaching caudal peduncle when adpressed; fin margin concave. Anal fin shorter than head length. Anal opening located immediately anterior to anal-fin origin. Caudal fin deeply forked with i, 9+8, i principal rays, both upper and lower lobes equal in length.

Scales moderate. Circumpeduncular scales 12, lateral transverse scale ½7/1/2½. Lateral line complete with 30–32 + 2–3 scales. Vertebrae 18+17= 35 including complex vertebra.

Colour: In a fresh specimen, dorsal and dorsolateral surfaces of head and body faintly brown, ventral portion anterior to pelvic-fin origin silver coloured. Belly creamy to golden yellowish and with 7–10 dark blue bars on the sides; first anterior-most dark blue bar extends beyond lateral line, sometimes first two or three anterior-most bars touch lateral line. Dorsal Etymology

The species name ‘profundus’ (Latin, meaning deep) is in reference to its great body depth, an adjective.

Distribution

Presently known only from the Koladyne River at Mizoram ( Fig. 1 , Image 2 ).

fin hyaline with a row of elongated black marks. Pectoral, pelvic and anal fins golden yellow with hyaline distal margins. Caudal fin edged with black, faintly yellowish-green at the base.

In 10% formalin, body creamy, slightly dark dorsally. Dorsal fin hyaline with a row of elongated black marks. Caudal fin hyaline, edged with black. Pectoral, anal and ventral fins hyaline without dark bands.

Figures

Image 1. Barilius profundus sp. nov., side view of paratype, MUMF 27021, 69.9mm SL

Figure 1. Map showing type locality of Barilius profundus sp. nov. indicated as a star.

Image 2. Koladyne River at Kolchaw, Mizoram, habitat of Barilius profundus sp. nov.