Putao Baril

description

Description. Meristic and morphometric data listed in Table 1. Head short and compressed. Head length usually larger than head depth. Mouth terminal, upper jaw slightly longer in some individuals, mouth cleft just below level of midpoint of eye, mouth corner below anterior edge of orbit. One row of small horny tubercles on ventral side of dentary around midline present, 1 − 3 rows of large horny tubercles on lateral aspects of dentary, median densely arranged (Figure 2). Small tubercles present on snout tip and anterior lachrymal. Eyes large, situated in anterior and upper half of head. Interorbital space convex. Gill membrane not connected to isthmus. Barbels absent, even in juveniles. Body compressed. Dorsum outline almost straight, descending after dorsal-fin origin. Abdomen rounded, more curved than dorsum. Dorsal-fin rays ii, 7 (14). Dorsal fin inserted posterior of posterior end of pelvic-fin base; distance between dorsal-fin origin and caudal-fin base almost equal to distance from dorsal-fin origin to middle to anterior orbit. Anal-fin rays ii, 9 (14). Anal-fin origin posterior of vertical through posterior of dorsal-fin base; analfin truncate, extending to around midpoint o

Opsarius putaoensis, a new species of subfamily Danioninae (Actinopterygii, Cyprinidae) from the Irrawaddy River basin in northern Myanmar

diagnosis

Diagnosis. Opsarius putaoensis is distinguished from its congeners in the subcontinent of India and Southeast Asia based on the following combination of characters: barbels absent (vs. present in most species with fewer than 11 branched anal-fin rays, except O. chatricensis, O. barna, and O. arunachalensis); dentary with parallel rows of tubercles; snout much shorter than eye diameter; mouth gape below anterior edge of orbit; pectoral and pelvic axial scales lobate; lateral line completely perforated, with 35 − 38 scales; scale rows between dorsal-fin origin and lateral line 7 − 8; predorsal scales 15; circumpeduncular scales 12; branched dorsal-fin rays 7; branched anal-fin rays 9; branched pelvic-fin rays 7 (vs. 8 in most species except O. ngawa); insertion of dorsal-fin not reaching pelvic-fin base (vs. reaching in O. chatricensis); body with 6 − 7 vertical bars, extending to lateral line; and distal edge of dorsal fin black.

Opsarius putaoensis, a new species of subfamily Danioninae (Actinopterygii, Cyprinidae) from the Irrawaddy River basin in northern Myanmar

discussion

Remarks. Opsarius putaoensis is further differentiated from congeners based on the following characters: lateral-line scales 35 − 38 (vs. 30 − 32 in O. profundus and O. bernatziki; 32 − 36 in O. koratensis; 36 − 42 in O. barna, O. barnoides, O. dogarsinghi, O. gatensis, O. infrafasciatus, O. nelsoni, O. ornatus, O. pulchellus, and O. signicaudus; 42 − 45 in O. howesi, O. lairokensis, and O. ngawa; 47 in O. bonarensis; and 58 − 75 in O. tileo, O. dimorphicus, O. pectoralis, O. radiolatus, and O. shacra); predorsal scales 15 (vs. 16 − 18 in O. ardens and O. bakeri; 17 − 25 in O. barnoides, O. bendelisis, O. bonarensis, O. dogarsinghi, O. howesi, O. infrafasciatus, O. kanaensis, O. lairokensis, O. ngawa, O. ornatus, O. profundus, O. radiolatus, O. shacra, and O. signicaudus; and 28 − 30 in O. tileo and O. pectoralis); circumpeduncular scales 12 (vs. more than 14 in O. barnoides, O. chatricensis, O. howesi, and O. pulchellus; and 16 − 17 in O. ngawa and O. dogarsinghi); branched dorsal-fin rays 7 (vs. 8 − 9 in O. gatensis, O. lairokensis, and O. pulchellus; and 10 − 11 in O. ardens, O. bakeri, O. canarensis and O. malabaricus); branched anal-fin rays 9 (vs. 7 − 8 in O. arunachalensis,

Opsarius putaoensis, a new species of subfamily Danioninae (Actinopterygii, Cyprinidae) from the Irrawaddy River basin in northern Myanmar

distribution

Distribution. Rare, only known from Mali Hka River, near Putao, Kachin State, northern Myanmar (Figure 4). Other associated fish species recorded from the type locality include: Psilorhynchidae: Psilorhynchus brachyrhynchus; Cyprinidae: Opsarius barnoides, Garra bispinosa, Placocheilus dulongensis; Balitoridae: Homalopteroides rupicola; Nemacheilidae: Schistura sikmaiensis, Schistura malaisei.

Opsarius putaoensis, a new species of subfamily Danioninae (Actinopterygii, Cyprinidae) from the Irrawaddy River basin in northern Myanmar