Freshwater fishes of three tributaries of the Pentecost River, Kimberley, Western Australia

WA Museum Records and Supplements | Updated 7 years ago

INTRODUCTION – Freshwater fish diversity in Australia increases dramatically in the tropical north when compared to southern parts of the continent (Unmack 2001; Allen et al. 2002) and there is still much to be documented in terms of species diversity, distributions, systematics and ecology. New, novel forms continue to be recorded from remote regions of Australia (e.g. Pusey and Kennard 2001; Morgan et al. 2013, 2014a; Raadik 2014), and recent research using genetic techniques suggest that there may be two to three times the number of species actually present than is currently recognised (Adams et al. 2013; Hammer et al. 2013; Raadik 2014). Hence, detailed surveys and taxonomic reviews of local fish faunas are likely to provide important and exciting biodiversity updates, as well as contribute to natural resource management and conservation.

From an ichthyological perspective, Western Australia’s Kimberley region encompasses the entire Kimberley Province as well as the western portion of the Northern Province (Unmack 2013; Morgan et al. 2014b). Several biodiversity surveys have examined Kimberley freshwater fishes (e.g. Allen 1975; Hutchins 1981; Allen and Leggett 1990; Morgan et al. 2004a) and have identifi ed 49 species. The Kimberley supports considerable endemism among freshwater fi shes (30–40%; Unmack 2001, 2013; Allen et al. 2002; Morgan et al. 2011), including two endemic genera. The remaining species range across northern Australia, with varying distributions. However, due to the relatively inaccessible landscape of much of the region, many waterways remain poorly surveyed, or not surveyed at all, particularly in the Northern Province, and the eastern parts of the Kimberley Province (Morgan et al. 2011). A complex geological and landscape history of the region has likely been responsible for high endemism and deep genetic divergences (Unmack 2001; Pepper and Keogh 2014).

Here we report on a recent survey of tributaries of the Pentecost River catchment in the east Kimberley that flow through Karunjie and Durack River stations. The only published survey of freshwater fi shes in these tributaries is that of Allen and Leggett (1990), whose collections included only six species from two sites (50, 51) in the Durack River on Karunjie Station. Ten species were collected from Durack River and Bindoola Creek by G.R. Allen in 1977 (seven of which were additional to Allen and Leggett 1990) and are held in the collection of the Western Australian Museum (WAM). Given that other, well studied river systems of the Kimberley have much higher biodiversity (Morgan et al. 2011), we predicted this total of 13 species likely refl ects a low sampling effort rather than a depauperate fauna.