Chilatherina pricei

Allen and Renyaan, 1996

Price’s Rainbowfish

Species Summary

Chilatherina pricei is a small stream dwelling species, growing to a length of about 7 to 10 cm. They were described by Gerald R. Allen and Samuel J. Renyaan in 1996 on the basis of 23 specimens collected in 1991 and 1995 from the Reifafeif River near Warironi Village on Yapen Island, off the central north coast of West Papua. They are similar to C. fasciata from the northern New Guinea mainland, but differ in colouration and have a shorter, blunter snout with the maxillary reaching the level of the eye (falling well short of eye in C. fasciata). It is also similar to C. alleni from the Derewo and Wapoga river systems of West Papua, but lacks a prominent midlateral stripe and reddish fins (males), and differs in modal counts of soft anal rays (usually 24–27 in C. pricei versus 19–24 in C. alleni), and number of cheek scales (usually 19–23 in C. pricei versus 16–18 in C. alleni).

The body colour is overall silvery-grey to bluish; scales on back sometimes with golden or yellow margins, wider on upper and lower edge of scale and forming a longitudinal yellow stripe between each scale row. Scales on caudal peduncle sometimes entirely yellow. About 5–10 dull grey to dark blue bars on lower half of side between level of pelvic fin base and middle of anal fin; some individuals have 2–6 small dark blue spots on mid-lateral scale row or on scale row immediately above, on rear half of body. Fins mainly translucent bluish, except dorsal and anal fins of mature males often golden yellow.

Etymology

The species is named in honour of David Price (b. 1959), naturalist, ecologist, linguist, translator and community development consultant, for his keen interest in the natural history of New Guinea; he lived periodically on Yapen Island, the type locality, making valuable collections of fishes and frogs.

Etymology compiled from C. Scharpf (2021), “Fishes of Sahul: An Etymological Survey (Part 4), the Rainbowfishes”, Fishes of Sahul 35(1): 1706–1714, and etyfish.org.

Distribution & Habitat

The Reifafeif River habitat is typical of numerous streams on Yapen Island, which no doubt are populated by this species. Yapen Island is situated in Cenderawasih Bay (formerly Geelvink Bay) off the northern coast of West Papua. It is a narrow, elongate (approximately 170 km long and up to 25 km wide) island with a central spine of mountains which rise to a maximum elevation of 1500 metres, and was once part of the New Guinea mainland. It has an area of approximately 2424 km2. The mountain range is dissected by numerous independent drainage systems, such as the Reifafeif River. The streams rise in the steep mountains and plunge to a relatively narrow (3–5 km wide) coastal plain, which is the home of C. pricei and most other freshwater fishes on Yapen. The main channel of the Reifafeif River on the coastal plain is approximately 15–30 m wide and in non-flood periods averages about 1–2 m in depth. Water temperatures and pH in July 1995 ranged between 24.2°–26.4°C and 7.5–8.1. Progressing inland, the river quickly narrows as it approaches the mountains and is characterised by scenic rapids, waterfalls, and deep pools. Chilatherina pricei is abundant in the main channel, usually over rock or boulder bottoms. It forms midwater aggregations that feed on algae and small invertebrates, particularly insects. Although the river flows through rainforest and gardens, it is generally open to sunlight over the coastal plain. Melanotaenia japenensis is sometimes found with C. pricei, but seems to be more common in smaller, shaded tributaries, rather than the main channel.

Remarks

This species was named after David Price, in recognition of his keen interest in the natural history of New Guinea. He collected the type specimens of Chilatherina pricei.

References

Allen G.R. and S.J. Renyaan (1996) Chilatherina pricei, a new species of Rainbowfish (Melanotaeniidae) from Irian Jaya. Revue française d'Aquariologie 23 (1-2): 5-8.