Barilius malabaricus 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 : 402-404

Barilius malabaricus Jerdon

( Figs. 6 , 7 )

Opsarius malabaricus Jerdon, 1849: 329

Barilius canarensis ( Menon, 1999:16) , not Jerdon 1849 Barilius bakeri (Remi Devi et al., 2005:124) , not Day, 1865

Material examined. ZSI/SRC, F.8815, 90.7 mm SL, 12°31’38”N, 75° 25’35”E, Payaswini River, Karnataka, India, A. Rai. ZSI/SRC, F.8816, 61.8–76.8 mm SL, 4 ex., same collection data. MKC 416, 5 ex., 61.8– 42.6 mm SL, Valapattanam River, Irrity, Kerala, India, N. Sood.

Diagnosis. Barilius malabaricus is distinguished from B. ardens by its unique colour pattern, consisting of a single or 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, if present, 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 & 6 ) Moreover, B. malabaricus can be distinguished from B. ardens by its fifth ceratobranchial, which has 5+4+2 (vs. 5+4+3) teeth. B. malabaricus can be distinguished from B. canarensis and B. bakeri by having 11½ (vs. 10½) branched dorsal-fin rays and 14½–15½ (vs. 13½) branched anal-fin rays, and having the dorsal and anal fins margined with bright orange (vs. broadly margined with white: see Figs.4,6 & 9). B. malabaricus can further be distinguished from B. canarensis and B. bakeri by having 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 6 , 7 for general appearance. Body deep, 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, diameter about one-third HL. Mouth oblique, angle of gape reaching middle 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 11½ (10) branched rays, posterior margin slightly concave, origin anterior to analfin origin. Pelvic fin short, not reaching anal-fin origin, with 1 simple and 8 (10) branched rays. Anal fin with 3 simple and 14½ (7)–15½ (3) branched rays, ventral margin deeply concave, a sharp curve among first few branched rays. Pectoral fin with 1 simple and 11 (7)–12 (3) branched rays. Caudal fin deeply forked, lobes subequal, lower lobe slightly longer, with 1+9+8+1 rays. Lateral line complete, slightly curved with 36 (7), 37 (2) or 38 (1) + 1 (10) pored scales. Predorsal scales 15(6), 16 (2) or 17 (2); scales in transverse line on body ½9 (4), 9 (3), ½8 (3) /1/2½ (5)–3 (5) between dorsal-fin origin and pelvic-fin base, 2½ (5)–3 (5) scales between lateral line and anal-fin base. Gill rakers slender, well-defined, 2 (3), 3 (7) + 8 (3), 9 (7) rakers on first gill arch. Fifth ceratobranchial with 5+4+2 teeth.

Coloration. In life (see Fig. 6 ), body bright bluish-silver with one or two rows of spots on flank, first row with 10–13 round or oval bluish-green spots 1–2 scales high and 1–2 scales wide, second row (if present) with 3–4 smaller spots reaching up to anal-fin origin. Sometimes in large specimens spots of second row further break up into a smaller third row consisting of 2–3 minute spots. Dorsal fin and anal fin bases black, fin margins lined with orange sometime mixed with white. Caudal fin black, medial rays and lobe tips white.

Preserved specimens ( Fig. 7 ) lose bright colours: greyish, darker on the dorsal side, progressively becoming lighters towards the abdomen, which is white. The spots on body dark grey. Fins opaque, dorsal, anal and caudal with black bases black.

Distribution. Barilius malabaricus was collected from the Payaswini and Vallapattanam Rivers, both of which flow through north Kerala, but probably occurs throughout a wider range in the southern Karnataka and northern 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 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 7. Barilius malabaricus, ZSI / SRC, F. 8815, 90.7 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).