Blue Moon Danio

description

Description. Measurements and counts were taken from 10 specimens, 59.5 – 76.9 mm SL (Table 1), representing the largest adults available, supplemented by counts from 13 additional X-radiographed specimens. All measured specimens were examined for gonads, and all have ripe ovaries and testes. The two largest specimens, 74.6 and 76.9 mm SL, are female, and male, respectively. Body laterally compressed, elongate, females slightly more deep-bodied than males (31.4 – 35.8 % SL vs. 29.9 – 31.0 %), and with deeper (16.5 – 18.7 % SL vs. 15.8 – 16.9 %) and wider (13.5 – 14.6 % SL vs. 12.9 – 13.5 %) head. Predorsal contour straight, ascending, sloping posteriorly from dorsal-fin insertion. Prepelvic contour strongly curved, more so in females; chest conspicuously more compressed below pectoral fin, but not keeled. Snout short, rounded in dorsal aspect, subtriangular in lateral aspect, about as long as eye diameter. Infraorbital process broader than high, with truncate distal margin which usually slightly irregular. Danionine notch caudally margined by well developed anteromediad projecting laminar dentary process. Skin cover absent from distal part of infraorbital process, dentary process,

Devario xyrops, a new species of danionine fish from south-western Myanmar (Teleostei: Cyprinidae)

diagnosis

Diagnosis. Distinguished from all other species of Devario except D. anomalus Conway et al. (2009) by the colour pattern, with a dark blotch anteriorly on the side composed of 4 – 5 short partly confluent vertical bars which may also be confluent to form a homogeneous blotch, and a wide dark horizontal band (P stripe) posteriorly on the side. Distinguished from D. anomalus by proportional measurements and meristics, most important by deeper body (29.9 – 35., 8 % SL, vs. 25.0 – 26.8 % SL) and fewer lateral line scales (31 – 33, modally 32 vs. 33 – 35, modally 34). Distinguished from all barred species of Devario also by presence of an infraorbital process.

Devario xyrops, a new species of danionine fish from south-western Myanmar (Teleostei: Cyprinidae)

etymology

Etymology. The specific epithet refers to the sharp, exposed bony margin of the supraorbital and the wide infraorbital process, and is combined from the Greek xyron (DρOv), razor, and ops (ωΨ) eye. It stands as a noun in apposition. Geographical distribution and habitat. Known only from small streams on the western slope of the Rakhine Yoma, north and south of Thandwe (Fig. 4). The type locality (Fig. 5) is the same as for Garra vittatula (Kullander & Fang, 2004: 265). It was a small forest river, at the time of sampling in the low water season reduced to a series of connected pools, up to 2 m wide, and nowhere more than 1 m deep. The water was clear, colourless, and slow-flowing or stagnant. The stream bottom consisted of stones, gravel and rock. Devario xyrops was the dominant species. Other species included the cyprinids Garra rakhinica Kullander & Fang, G. vittatula Kullander & Fang, Danio feegradei Hora, also endemic to the western Rakhine State, and Xenentodon cancila (Hamilton) (Belonidae), Channa sp. (Channidae), Lepidocephalichthys sp. (Cobitidae), and Sicyopterus fasciatus (Day) (Gobiidae). Puntius binduchitra (Hora) (Cyprinidae); another endemic cyprinid easily identifie

Devario xyrops, a new species of danionine fish from south-western Myanmar (Teleostei: Cyprinidae)

materials_examined

Holotype. NRM 45658, adult female, 60.6 mm SL; Myanmar: Rakhine State: Thandwe: Thade River drainage: Taunggok, Yan Khaw Chaung, ca 4 km on logging road from Gwetauk village, 23 km on road Taunggok – Pyay; 21 Mar 1998, S. O. Kullander & R. Britz (SOK- 98 - 010). Paratypes. All from Myanmar, Rakhine State. NRM 40843, 21, 44.8 – 76.9 mm SL; NRM 41674, 1, 55.2 mm SL; NRM 45596, 10, 9.5 – 21.9 mm SL. Same data as holotype. — NRM 40835, 6: 33.3 – 49.7 mm SL; NRM 41673, 1, 41.8 mm SL; Kananmae Chaung, near Leldee village, by foot 45 min from Gwechaung village at km 18 on road Thandwe – Taunggok. 20 Mar 1998. S. O. Kullander & R. Britz (SOK- 98 - 007). — BMNH 2009.5.5.20 – 24, 5, 36.8 – 74.0 mm SL; Kyeintali Chaung; 15 Oct 2008, Thein Naing.

Devario xyrops, a new species of danionine fish from south-western Myanmar (Teleostei: Cyprinidae)