Barilius canarensis (Jerdon)

Marcus Knight, J. D., Rai, Ashwin, D’Souza, Ld. K. P. & Vijaykrishnan, Balaji, 2015, Barilius ardens (Teleostei: Cyprinidae), a new species from the Western Ghats, India, with redescription of B. malabaricus and B. canarensis, Zootaxa 3926 (3), pp. 396-412 : 400-402

Barilius canarensis (Jerdon)

( Figs. 4 , 5 )

Opsarius canarensis Jerdon, 1849: 329 Material examined. ZSI/SRC, F.8814, 81.9 mm SL, 12°50’23”N, 75°13’47”E, Netravathi River, Karnataka, India, A. Rai. MKC 415, 2 ex., 81.9–83.7 mm SL, same collection data.

Diagnosis. Barilius canarensis is distinguished from B. ardens by its unique colour pattern, consisting of a double row of spots along the length of the body, the first row with 9–13 round or oval bluish-green spots 1–2 scales high and 1–2 scales wide and the second row, with 3–4 smaller spots reaching up to the anal-fin origin (vs. a row of 7–9 large, vertically-elongate, bluish-green blotches 4–6 scales high and 2–3 scales wide along the length of the body, of which in large adults the first three blotches are fragmented into a smaller row of blotches: see Figs. 1 & 4 ) Moreover, B. canarensis can be distinguished from B. ardens by its fifth ceratobranchial, which has 5+4+2 (vs. 5+4+3) teeth; by possessing 14–15 (vs. 16–18) predorsal scales, and having the dorsal and anal fins margined with white (vs. broadly margined with bright orange: see Figs. 1 & 4 ). B. canarensis can be distinguished from B. malabaricus by having 10½ (vs. 11½) branched dorsal-fin rays and 13½ (vs. 14½–15½) branched anal-fin rays, and having the dorsal and anal fins margined with white (vs. broadly margined with bright orange: see Figs. 4 & 6 ). B. canarensis can be distinguished from B. bakeri by its unique colour pattern, consisting of a double row of spots along the length of the body, the first row with 9–13 round or oval bluish-green spots 1–2 scales high and 1–2 scales wide and the second row, with 3–4 smaller spots reaching up to the anal-fin origin (vs. only a single row of spots along the length of the body); having 35–36 + 1 (vs. 37–38 + 1) lateral line scales and slender, well-defined gill rakers (vs. fleshy, rudimentary gill rakers: see Figs. 10 ).

Description. See Tables 1 and 2 for morphometric and meristic characters, and Figures 4 and 5 for general appearance. Body deep, its depth about one-third SL, laterally compressed, dorsal profile slightly curved, ventral profile deeply convex. Caudal peduncle deep, depth almost equal to length. Head small, length about one-fourth SL, depth more than three-fourths length, dorsal profile almost straight, a slightly raised at nape. Eyes large, placed forward, their diameter about one-third HL. Mouth oblique, angle of gape almost reaching posterior margin of orbit. Two pairs of minute barbels (rostral and maxillary). Nostrils closer to eye than to snout tip. Lower jaw slightly longer than upper jaw. Snout length about one-third HL.

Dorsal fin with 3 simple and 10½ (3) branched rays, posterior margin slightly concave, origin anterior to analfin origin. Pelvic fin short, not reaching anal-fin origin, with 1 simple and 8 (3) branched rays. Anal-fin with 3 simple and 13½ (3) branched rays, ventral margin deeply concave, a sharp curve among first few branched rays. Pectoral fin with 1 simple and 10 (1)–11 (2) branched rays. Caudal fin deeply forked, lobes subequal, lower lobe slightly longer, with 1+9+8+1 principal rays. Lateral line complete, slightly curved, with 35 (2) or 36 (1) + 1 (3) pored scales. Predorsal scales 14(1)–15 (2); scales in transverse line on body ½8/1/2 (2)–2½ (1) between dorsal-fin origin and pelvic-fin base, 2½ (3) scales between lateral line and anal-fin base. Gill rakers, slender, well-defined, with 3 (3) + 8 (2), 9 (1) rakers on the first gill arch. Fifth ceratobranchial with 5+4+2 teeth ( Fig. 3 B).

Coloration. In life (see Fig. 4 ), body bright greenish silver, with two rows of spots along flank, first row with 9–11oval bluish-green spots 1–2 scales high,1–2 scales wide and second row with 3–4 smaller spots reaching up to anal-fin origin. Sometimes in large specimens spots of second row further breaking up into a smaller third row consisting of 2–3 minute spots. Dorsal fin and anal fin bases black, fin margins lined with white. Pelvic fins tipped white; pectoral fins tipped orange. Caudal fin black, tips white.

Preserved specimens ( Fig. 5 ) lose bright colours: greyish brown, darker on dorsum, progressively lighter towards abdomen, which is white. Spots on body dark grey. Fins opaque; dorsal, anal and caudal with black bases.

Distribution. Barilius canarensis was collected from the Netravathi River in south Canara (south-western Karnataka) during our surveys, but probably occurs through a wider range in the south Karnataka and north Kerala regions.

Figures

FIGURE 1. Barilius ardens, A, male, unregistered specimen in life, ~ 90 mm SL; B, juvenile unregistered specimen in life, ~ 20.6 mm SL; C, female, paratype, prior to fixation, ZSI / SRC, F. 8813, 85.5 mm SL.

FIGURE 3. Fifth ceratobranchial of, A, Barilius ardens, MKC 385, 85.5 mm SL; B, B. canarensis, MKC 415, 83.7 mm SL; C, B. bakeri, MKC 384, 68.7 mm SL (Scale bar = 1 mm).

FIGURE 4. Barilius canarensis, MKC 415, A, 83.7 mm SL; B, 81.9 mm SL.

FIGURE 5. Barilius canarensis, ZSI / SRC, F. 8814, 81.9 mm SL.

FIGURE 6. Barilius malabaricus, A, unregistered specimen in life from aquarium trade ~ 80 mm SL, Kannur, Kerala; B, MKC 416, prior to fixation, 61.8 mm SL, Valapattanam river, Kerala; C, ZSI / SRC, F. 8816, prior to fixation, 76.8 mm SL, Payaswini River, Kerala.

FIGURE 10. First gill arch, A, Barilius bakeri, MKC 384, 68.7 mm SL; B, B. canarensis, MKC 415, 63.4 mm SL (Scale bar = 2 mm).