Melanotaenia kolaensis

Species Summary
Males of Melanotaenia kolaensis are grey-brown dorsally on the head, nape, and predorsal region; cheek and side of snout blue grey, cheek usually with silvery reflections; operculum blue-grey with prominent pale-edged, red spot (about two-thirds pupil size); iris pale yellow to silvery-white with tan patch at lower rear corner; scales of upper back blue with narrow brown margins; dark blue to blackish midlateral stripe (1-2 scales wide), especially conspicuous on posterior third of body, edged below with prominent white to pale blue stripe that occupies lowermost part of caudal peduncle, extending forward to middle of sides; ventral portion of body greyish-white to pale blue except pair of dark blue, irregular stripes between scale rows, often present above anal fin and large, bright blue patch just behind and below pectoral-fin base; first dorsal fin bluish; second dorsal fin blue, grading to red posteriorly and on outer edge of fin; anal fin blue basally and broadly red on outer portion; caudal fin red; pelvic fins white; pectoral fins semitranslucent. Paratypes were generally similar, although there is some variation in the intensity of the pale stripe on the lower caudal peduncle, which varies from brilliant white to pale blue. Females are generally similar to males, but with slightly less vivid colours. Juveniles conform to the general M. senckenbergianus pattern except for an irregular dark blue strip on the ventral side, diffuse anteriorly and becoming more vivid above the anal fin.

This species was named kolaensis with reference to the Kola Island type locality.

Distribution & Habitat
Melanotaenia kolaensis is currently known only from two drainages separated by about 7-8 km on Kola, the northernmost large island of the main Aru Group. The island has an area of about 300 km² and judging from Google Earth images has approximately 10-12 freshwater drainage systems, of which the one (Sungai Tasinwalas) where the type locality is situated penetrates the farthest inland. The type locality is situated approximately 11 km upstream from the sea. The main river makes a gradual transition from a broad, mangrove-lined tidal stream with brackish conditions to an exceptionally narrow and steep-walled, limestone channel in woodland habitat with pure fresh water. The fish were located about 100 metres beyond the navigable (via small outboard boat) limit of the stream.

Literature
Allen G.R., R.K. Hadiaty, P.J. Unmack and M.V. Erdmann (2015) Rainbowfishes (Melanotaenia: Melanotaeniidae) of the Aru Islands, Indonesia with descriptions of five new species and redescription of M. patoti Weber and M. senckenbergianus Weber. aqua, International Journal of Ichthyology 21(2): 66-108.

Adrian R. Tappin
June, 2015