Oreichthys incognito, Marcus Knight, J. D. & Kumar, Rahul G., 2015

Marcus Knight, J. D. & Kumar, Rahul G., 2015, A review of the species of Oreichthys (Teleostei: Cyprinidae) in the Western Ghats, India, Zootaxa 3914 (2), pp. 157-167 : 160-161

Oreichthys incognito , sp. nov.

( Fig. 3 )

Holotype. ZSI FF 5250, 31.4 mm SL, 11° 00' 10.9" N 76° 27' 06.1" E Kunthipuzha, upstream of Mannarkkad, Kerala State, 11.10.2011, Rahul Kumar et al.

Paratypes. NBFGR.2014.08.1.2–3, 2 ex., 20.4–23.9 mm SL, collection details same as holotype.

Diagnosis. Oreichthys incognito sp. nov. can be distinguished from its congeners by a combination of characters including 21–22+1 scales in the longitudinal series with 5 pored scales; ½3/1/1½ scales in the transverse row; 8 predorsal scales and a vertical black bar on the dorsal fin.

Description. See table 1 for morphometric characters, and fig. 3 for general appearance. Body deep, laterally compressed, its dorsal profile arched with a hump at the nape, ventral profile convex. Body deepest at the dorsal-fin origin, its depth almost a third of its length, decreasing towards caudal-fin base. Dorsal fin with two simple and 8½ branched rays, its posterior margin concave, its height almost equal to body depth. Pelvic fin reaching anal fin origin with one unbranched and 7 branched rays; anal fin immediately behind the anal opening with two unbranched and 5½ branched rays, not reaching the caudal fin base; and pectoral fin with one simple and 11 branched rays reaching beyond pelvic fin origin. Caudal fin deeply forked, its lobes subequal, with 19 (1+9+8+1) rays. Lateral line incomplete, with 21 (2)–22(1)+1 scales in the longitudinal series, of which 5 scales are pored. Predorsal scales 8; scales in transverse line on body ½3/1/1½. Gill rakers absent.

Head small, its length almost equal to body depth, its dorsal profile ascending with an indentation at the nape. Eyes large, placed forward, their diameter a little larger than snout length. Mouth small oblique, lips thin, lower jaw shorter than the upper jaw, angle of gape reaching behind the anterior margin of the eye orbit, barbels absent. Snout blunt, devoid of tubercles. Nostrils closer to eye than snout tip. Nine rows of papillae present on sub-orbital and extending onto the pre-opercle. Caudal peduncle slender, its length a little more than its depth.

Coloration. Formalin-fixed and alcohol-preserved specimens are brownish with a faint humeral spot covering 3rd to 5th lateral line scale. All fins hyaline with a vertical black bar on the dorsal fin. Scales with dark outer edges and scattered melanophores along the fin bases. In life, body silver, dorsal fin grey with a tinge of red on the anterior end and a vertical black bar. All other fins hyaline. A faint black spot on the caudal fin base, which may sometimes be absent (Image 2). The species looks very similar to Puntius vittatus .

Etymology. The species name incognito = having ones true identity concealed, is an allusion to the species probably being overlooked in earlier ichthyofaunal surveys due to its similarity to Puntius vittatus . The species name is a noun in apposition.

Distribution and habitat. Oreichthys incognito sp. nov. is at present known from its type locality, the Kunthipuzha upstream of Mannarkkad in Kerala, India. The river there at the time of collection was shallow, with rapid flow over a substrate of gravel and cobbles. Stands of Pandanus and other riparian vegetation were present along the banks. The specimens were collected from close to the bank, amidst submerged vegetation.

O. duospilus O. incognito O. coorgensis O. cosuatis

Holotype Range Holotype Range Holotype Range Range

NBFGR. ZSI FF 5250 ZSI FF 1715

2014.08.1.1

Figures

FIGURE 3. Oreichthys incognito sp. nov.: A, holotype, ZSI FF 5250, 31.4 mm SL. B, Live specimen from Kunthipuzha, Kerala, not preserved.