Chilatherina alleni - photo© Gerald Allen

Chilatherina alleni

Species Summary
Chilatherina alleni have the upper half of the body brownish anteriorly becoming turquoise posteriorly, each horizontal scale row separated by narrow brown or dull orange stripe. Mid-lateral band dark blue, occupying about two horizontal scales rows, from upper rear corner of eye to base of caudal fin, interrupted on its lower edge by about five, white indentations in area just behind pectoral fin. Lower half of body mainly dark silver, except for intense white stripe with lower margin of dull orange occupying scale row immediately below mid-lateral band. 4-5 diffused charcoal coloured bars on lower side between level of pelvic fin base and fin origin.

The first dorsal fin is light blue; second dorsal and anal fins translucent bluish becoming reddish on margins. Caudal fin translucent reddish. Pectoral and pelvic fins mainly translucent. Females slightly less intense with median fins mainly translucent to bluish without any red. Besides the colour differences noted above, males are typically deeper bodied than females. In addition, the second dorsal and anal fins short and blunt in females and somewhat elongated and pointed in males. There is a wide variation in colouration of this species depending on habitat. One variation has a reddish back, red fins and bright yellow stripe in the middle of the body.

Chilatherina alleni may reach a maximum size of 9 cm, but usually less than 7 cm. Males are usually much larger and deeper bodied than females.

Distribution & Habitat
Chilatherina alleni was collected from a tributary of the Aiborei River, which is part of the Siriwo drainage situated in the Central Highlands southeast of Cenderawasih Bay. The river is approximately five meters wide, with a maximum depth of about one meter, although most pools which Chilatherina alleni tend to favour are no more than 70 cm in depth. The substrate consists of gravel and rocks. The water is cold and clear and swiftly descends from the mountains through the village adjacent to the airstrip. In November 1994 water pH was 7.0.

Remarks
Named in honour of Gerald R. Allen, in recognition of his outstanding contribution to ichthyology and his deep commitment to the study and preservation of the aquatic fauna of New Guinea. This species is not currently available in the aquarium hobby.

Literature
Price, D. S. (1997). Chilatherina alleni, a new species of rainbowfish (Melanotaeniidae) from Irian Jaya. Revue française d'Aquariologie 24(3-4): 79-82.

© Copyright Adrian R. Tappin
Updated December, 2008.