Pristolepis malabarica ( Günther 1864 )

Pristolepis malabarica ( Günther 1864) View in CoL

Fig. 1 View FIGURE 1 , Table 2.

Diagnosis. Pristolepis malabarica can be distinguished from its two southern Indian congeners by the following characters: from P. marginata by the number of anal-fin spines (3 vs. 4–5), a typically deeper body (mean 48.2 ± 2.5 % SL vs. mean 42.9 ± 2.4 % SL) and by having the rays of the median fins with yellow to orange margins, when freshly collected (vs. white); and from P. rubripinnis in having the rays of the median fins with yellow to orange margins, when freshly collected (vs. red), an olive-green to brown iris (vs. bright-red), and fewer scales rows above the lateral line (3 vs 4–5) and below it (9 vs. 10). The genetic divergence between topotypic P. malabarica and topotypic P. marginata and P. rubripinnis for the COI sequences is 11.5–13.2% and 17.0–17.4%, respectively.

Pristolepis malabarica can be distinguished from the three currently recognized species of Pristolepis in southeast Asia by the following characters: from P. fasciata , P. grootii and P. pauciradiata by fewer dorsal-fin rays (13–14 vs. 15–16), from P. fasciata and P. pauciradiata by fewer scales above the lateral line (3 vs. 5), from P. fasciata by fewer scales below the lateral line (9 vs. 10), and from P. grootii by the parasphenoid tooth patch extending anteriorly to middle of orbit (vs. extending to anterior margin of orbit).

Description. Body laterally compressed, subcylindrical to oval, covered in large, thick ctenoid scales, covering also bases of pectoral, dorsal, anal, and caudal fins; axillary scale at base of pelvic fin. Head scaled, except between dorsal margin of orbit and snout. Posterior margin of opercle serrated and with two sharp spines. Angle of preopercle finely serrated. Lateral line interrupted, resulting in anterior portion with 19–23 perforated scales, posterior portion with 5–9 scales, scales sometimes extending onto caudal fin. Mouth terminal, slightly protrusible.

Teeth generally conical, retrorse, but molariform in regions of parasphenoid and basihyal-basibranchial toothplate. Premaxilla with teeth arranged in several rows along articular process, comprising outer row of larger caniniform teeth and irregular inner rows of minute teeth. Anteriormost two to three projecting parasymphyseal caniniform teeth larger than posterior teeth. Maxilla edentulous; dentary with more than eight rows of teeth; outermost row with caniniform teeth, of which 3-4 parasymphyseal caniniform teeth, interdigitate with parasymphyseal premaxillary canines in closed jaws. Parasphenoid tooth patch supporting more than six rows of teeth; anterior to mid-region with molariform teeth of varying size; posterior portion lined exclusively with antrorse conical teeth. Discrete cluster of conical teeth set in three rows on vomer. Apart from palatine with conical teeth, no dentition on other bones of hyopalatine arch. Pharyngobranchials 2 and 3 with rows of large pointed teeth, but upper pharyngeal toothplate 4 with smaller teeth, decreasing in size posteriorly. Molariform teeth of varying sizes, bordered by conical teeth on posterior part of basihyal-basibranchial tooth plate and on hypobranchial 3. Ceratobranchial 5 with larger teeth along medial area, smaller teeth distally.

Morphometric and meristic data are provided in Table 2. Dorsal fin with 13–15 spines followed by 11–14 rays, pectoral fin with 13–15 rays, pelvic-fin with 1 spine and 5 rays, and anal fin with 3 spines followed by 7–9 rays. Total vertebrae 25, with 13 abdominal + 12 caudal vertebrae (N=3). Lateral line scales 19–23 in anterior + 5–9 in posterior portion.

In adults, body olive-green to yellowish-brown, eyes intense olive-green to brown, with a yellowish margin. Fins yellowish-brown; pectoral, dorsal, anal and caudal-fin membranes with yellow to light orange margins (fading under stress). Juveniles with series of irregular yellowish bars along flanks, more conspicuous anteriorly, gradually more faded posteriorly.