Rasbora rheophila

HABITAT: The Sebuku specimens were obtained from a high gradient mountain stream in a large and deep pool somewhat isolated from the main stream and with counter current. The Ranau specimens were collected at an altitude of ca. 550 masl. The Kinarom specimen was collected at 120 masl, in a fast flowing hill stream draining from the northern area of Mount Kinabalu.

Sumber: Rasbora rheophila, a new species of fish from northern Borneo (Teleostei: Cyprinidae)

DESCRIPTION: General appearance is shown in Figures 1 - 2 and morphometric data of holotype and 8 paratypes are given in Table 1. Dorsal fin with 2 simple and 7 - 8 ½ branched rays; origin above lateral line scale 12 (1), 13 (7) or 14 (2). Pectoral fin slightly falcate, with 14 - 16 rays; a small axillary lobe present. Pelvic fin slightly pointed, with 9 rays; axillary scale present. Anal fin with 3 simple and 5 ½ branched rays. Caudal fin with 10 + 9 principal rays, 9 + 8 being branched. Caudal peduncle 1.94 - 2.24 times longer than deep. 31 (1), 32 (2), 33 (4) or 34 (2) scales along lateral line + 2 - 3 pored scales on caudal-fin base. Lateral line complete. 12 (1), 13 (5) or 14 (4) predorsal scales, ½ 4 / 1 / 2 ½ scales in transverse line, ½ 4 / 1 / 1 ½ scales in transverse line on caudal peduncle (½ 5 / 1 / 1 ½ in holotype), 1 ½ scales between lateral line and pelvicfin origin. Vertebral formula: 18 + 18 = 36 (1), 18 + 19 = 37 (4), 18 + 20 = 38 (1), 19 + 18 = 37 (5), and 19 + 19 = 38 (8) (from Kottelat & Vidthayanon, 1993: 164). A few scattered and irregularly shaped tubercles on lower jaw of Sebuku specimens. COLORATION: The colour pattern of the Pangakatan and Sebuku populations are illustrated in Figures 1 - 2. A dark stripe from head to end of hypural plate, over axial streak. Axial streak extending forward to gill opening. Lateral stripe black below axial streak and much paler, brownish or greyish, above. A blackish mid-dorsal stripe from nape to caudal-fin base. Dorsum greyish, with crescentic paler marks parallel to posterior scale margins. A narrow and faint line of black pigments above anal-fin base. Belly pale yellowish, with a few brown crescentic marks on anterior medio-lateral scales. In Sebuku specimens, caudal fin with a dark grey posterior margin, broader near the tip of the lobes; in Pangakatan specimens, margin narrow or absent on lower lobe and broader and more intense on upper lobe. In Kinarom specimen, margin very faint on lower lobe and narrow on upper lobe. Other fins hyaline. The paler coloration of specimen in Figure 2 compared to that in Figure 1 b is apparently due to it having been collected in a rainy period in murky water. Live coloration not observed due to very heavy rains at time of collecting of Sebuku specimens. When first observed at day light (following day), specimens with same colour pattern as described above.

Sumber: Rasbora rheophila, a new species of fish from northern Borneo (Teleostei: Cyprinidae)

DISTRIBUTION: Rasbora rheophila is known from Sabah (Labuk, Padas and Kinarom drainages) and Kalimantan Timur (Sebuku drainage) (Fig. 3). It is expected to occur in the headwaters of other drainages of Sabah, as well as in the northernmost part of Kalimantan Timur (for example in Sembakung drainage, which originates in Sabah).

Sumber: Rasbora rheophila, a new species of fish from northern Borneo (Teleostei: Cyprinidae)