Distribution of the Lake Eacham Rainbowfish in the Wet Tropics Region, North Queensland

Abstract

The Lake Eacham rainbowfish, Melanotaenia eachamensisAllen & Cross, 1982, was thought to be extinct in the wild until recentresearch demonstrated the presence of wild populations in a few tributaries ofthe upper Johnstone River and the upper Barron River, north Queensland, byusing the technique of DNA sequencing. We present the results of amultivariate analysis of a range of morphological and meristic characters ofrainbowfish collected from rivers of the Wet Tropics region, particularly theJohnstone River, that demonstrate that M. eachamensis iswidespread in the upper and lower reaches of the North and South Johnstonerivers and tributaries of the upper Tully River.M. eachamensis was most often the dominant species inthose locations where sympatry withM. splendida splendida was observed.M. eachamensis should be considered a stream-dwellingspecies rather than a lacustrine species although a significant lacustrinepopulation (Koombooloomba Dam) was detected.