Fishes of the genus
Recent collection of freshwater fishes from the Namya River of Ukhrul district, Manipur, Chindwin basin, included an undescribed species of
The description is based on formalin-preserved specimens. Counts, measurements, and terminology follow Kullander and Fang [
India, Manipur state, Ukhrul district, Namya River, close to Indo-Myanmar border, 72.5 mm SL; 24°52′N 94°39′E; Shangningam et al., 18.IV.2011 (MUMF 12042).
4 spec. same data as holotype, 28.1–53.9 mm SL (MUMF 12041,12043, 12044, 12045), one paratype (30.0 mm SL) dissected for osteology.
MUMF 6296–6305, 10 spec. 49.3–54.90 mm SL; India: Manipur, Phungdhar, Iril River. MUMF 4163–4166, 4 spec. 58.0–91.5 mm SL; India: Manipur: Tamenglong district, Noney, Iyei River. MUMF 4160–4162, 3 spec. 44.0–70.0 mm SL; India: Manipur: Tamenglong district, Noney, Iyei River. MUMF 8004–8008, 5 spec. 53.8–76.2 mm SL; India: Manipur: Conchak Lok stream of Nambul River. MUMF 5103–5106, 4 spec. 53.7–63.4 mm SL; India: Manipur: Churachandpur district, Khuga River.
The species is named after its type locality: Namya River.
A small species of
Morphometric data of the holotype and four paratypes are given in Table
Morphometric data of holotype and paratypes for
Holotype MUMF 12O42 | Range | Mean | SD | |
---|---|---|---|---|
Standard length (mm) | 72.5 | 28.1–72.5 | ||
Body depth | 19.0 | 19.0–21.0 | 20.0 | 0.8 |
Head length | 22.6 | 20.0–25.0 | 24.3 | 1.0 |
Head depth | 15.2 | 14.0–16.3 | 15.2 | 1.0 |
Head width | 18.0 | 17.0–20.0 | 19.0 | 1.3 |
Dorsal fin length | 21.0 | 21.0–23.1 | 23.1 | 1.8 |
Pectoral fin length | 23.0 | 23.0–25.0 | 24.0 | 0.8 |
Pelvic fin length | 19.0 | 18.3–20.0 | 19.0 | 0.6 |
Anal fin length | 19.4 | 17.4–21.0 | 20.0 | 1.3 |
Length of caudal peduncle | 15.0 | 13.0–15.2 | 14.0 | 1.0 |
Depth of caudal peduncle | 13.0 | 13.0–15.0 | 13.4 | 1.1 |
Predorsal length | 50.3 | 50.0–53.0 | 51.0 | 1.2 |
Prepectoral length | 20.3 | 19.3–21.4 | 20.5 | 0.8 |
Prepelvic length | 55.0 | 55.0–61.0 | 57.4 | 2.4 |
Preanal length | 79.0 | 79.0–85.3 | 81.3 | 2.7 |
Head depth | 67.0 | 54.3–83.0 | 66.0 | 10.7 |
Snout length | 51.0 | 46.0–61.0 | 51.4 | 5.8 |
Eye diameter | 15.0 | 15.0–25.4 | 19.0 | 4.1 |
Interorbital width | 49.0 | 45.0–63.0 | 50.0 | 7.3 |
Disc length | 34.0 | 34.0–44.0 | 39.0 | 4.7 |
Disc width | 53.0 | 44.3–56.0 | 52.0 | 4.4 |
Callous pad length | 23.2 | 21.1–34.0 | 25.3 | 5.0 |
Callous pad width | 33.0 | 27.2–44.1 | 34.6 | 6.1 |
Head width | 118.2 | 118.2–126.2 | 122.2 | 3.0 |
Body depth | 125.0 | 120.4–145.0 | 131.0 | 9.3 |
Anal-Vent distance | 33.1 | 28.0–33.3 | 30.3 | 3.8 |
Caudal peduncle length | 112.0 | 93.0–115.2 | 104 | 9.6 |
Two pairs of barbels: rostral: located anterolaterally, as long as eye diameter; maxillary: at the corner of mouth, shorter than rostral; anterior barbels short, extending to margin of rostral cap. Rostral cap well-developed; curved ventrally and connected with lower lip at the corners of mouth (Figure
Dorsal fin with ii, 6.5(5) rays, inserted anterior to pelvic fin, highest point of the body at dorsal fin origin, first branched ray longest, posterior end at same level with that of pelvic, posterior margin of dorsal fin straight. Pectoral and pelvic fins extending horizontally. Pectoral fin with i, 12(5) rays, origin close to gill opening, with round posterior margin, fourth branched ray longest end of pectoral fin not reaching pelvic fin origin, separated from it by 6-7 scales. Pelvic fin with i, 7.5(5) rays, origin situated vertically at base of second branched ray of dorsal fin rays, end of pelvic fin surpassing the anus, second and third branched ray longest separated from anal-fin origin by 2(4)–3(1) scales, posterior margin round, and length of vent-anal-fin origin about 27.5–33.3% distance of pelvic to anal-fin origin. Anal fin with ii, 4.5 rays, distal margin slightly concave, posterior end of anal-fin not reaching of caudal fin base extends to mid of caudal peduncle, distance of anal-fin origin to caudal-fin base equal to or slightly smaller than that of anal-fin origin to pelvic-fin origin, separated from pelvic fin origin by 8(4)–9(1) scales. Vent closer to anal-fin origin than to pelvic-fin origin, separated from anal-fin origin by 3(4)–4(1) scales. Caudal fin emarginated, upper lobe slightly longer than lower lobe, bearing 10 + 9(5) rays.
Lateral line complete with 31(5) scales. Scales in transverse row above lateral line and below lateral line from ventral fin origin 3.5(5) each. Circumpeduncular scale rows 14(5). Predorsal scales 13(5); scales arranged regularly, same size as flank scales. Both chest and belly scaled. Scales between vent and anal-fin base 3(3)–4(2). Gill rakers nine. Total number of vertebrae 32, consisting of 22 + 10 abdominal and caudal vertebrae.
In 10% formalin, body dorsum is greyish brown, lighter posteriorly, dull greyish brown on caudal peduncle. Ventrally, head, pectoral, and pelvic fin bases are yellowish. Dark brown spot is immediately posterior to dorsal gill opening. Dorsal fin is basally yellowish white, dark black band near the posterior margin. Pectoral fin is basally yellowish with greyish submarginal band on anterior rays. Pelvic and anal-fins are greyish white. Caudal fin is with a distinct W-shaped broad black band with lines of black spots anterior to its base.
In life, body background is greenish brown, with upper angle of gill opening with shining bluish shine. Fins are golden yellow. Dorsal fin is basally yellowish with broad black band near the posterior margins. Caudal fin is with a distinct W-shaped blue black band.
The species inhabits swiftly flowing clear water with gravel bottom and lush green algal bloom (Figure
Namya River, type locality and habitat of
Map showing type locality of
Key to species of
Key to
(1) | (i) Snout with proboscis | (2) |
(ii) Snout without proboscis | (7) | |
(2) | (i) Proboscis well-developed | (3) |
(ii) Proboscis incipient, represented by a truncate area in front of the nostrils | ||
(3) | (i) Proboscis bilobed with one large | |
(ii) Proboscis unilobed or quadrate | (4) | |
(4) | (i) Vent to anal distance more than 45% of pelvic to anal-fin distance | |
(ii) Vent to anal distance less than 40% of pelvic to anal-fin distance | (5) | |
(5) | (i) Simple dorsal fin rays two | |
(ii) Simple dorsal fin rays four | (6) | |
(6) | (i) Lateral line scales 34; anus to anal distance 32.1–39.2% of pelvic to anal distance | |
(ii) Lateral line scales 36-37; anus to anal distance 22.8–28.3% of pelvic to anal distance | ||
(7) | (i) Caudal fin with W-shaped black mark | (8) |
(ii) Caudal fin without W-shaped black mark | (9) | |
(8) | (i) Caudal fin forked | |
(ii) Caudal fin slightly emarginated | (10) | |
(9) | (i) Rostral lobe present | |
(ii) Rostral lobe absent | (11) | |
(10) | (i) Snout without tubercles | |
(ii) Snout with tubercles | (14) | |
(11) | (i) Snout without barbels | |
(ii) Snout with barbels | (12) | |
(12) | (i) Lateral line scales 30-31 | |
(ii) Lateral line scales more than 37-38 | (13) | |
(13) | (i) Simple dorsal fin rays two; depth of body 17.0–17.6% SL | |
(ii) Simple dorsal fin rays four; depth of body 20.4–24.6% SL | ||
(14) | (i) Rostral lobe absent, chest, and abdomen naked | |
(ii) Rostral lobe present, chest, and abdomen scaled |
The new species under description shares similar characters with
Of the seven species of
The presence of a prominent triangular-shaped rostral lobe on the snout easily distinguishes
A thorough revision of the species of
B. Shangningam is grateful to University Grants Commission (UGC) for providing University Research Scholarship, and W. Vishwanath is grateful to the Department of Science and Technology, Government of India (Project no. SR/SO/AS-50/2008).