Long live the King River Perchlet (Nannatherina balstoni)

Morgan, D.L., Beatty, S.J., Allen, M.G., Keleher, J.J. and Moore, G.I. (2014) Long live the King River Perchlet (Nannatherina balstoni). Journal of the Royal Society of Western Australia, 97 . pp. 307-312.

Abstract

Exactly 100 years following the discovery of Balston’s Pygmy Perch (Nannatherina balstoni) and its subsequent description from south-western Australia, it was added to the Australian Government’s endangered species list due to a contraction of the species range and its low abundance relative to sympatric species. The current study aimed to determine the historical and contemporary geographical range of the species, to quantify its range reduction and prioritise areas for ongoing monitoring and management. The original common name of this species, the King River Perchlet, was derived from the type locality of the two syntypes deposited at the British Museum of Natural History. Only one syntype remains. Based on a review of published information and unpublished data held by the authors, the apparent contemporary area of occurrence of N. balstoni is now ~69% of its historical distribution. The remaining syntype from the King River represents the only known specimen from that system and the species is no longer known to occur there. Similarly, the species appears to have been extirpated from the Moore River at the northern limit of its range during the latter part of the 20th century, and presumably also from many rivers of the Swan Coastal Plain as well as Turner Brook in the extreme south-western corner of its range. Based on genetic differences between populations, it is proposed that the loss of these populations is likely to have resulted in an irreversible loss of evolutionary significant units. A recovery plan is critical for the management of the species, with on-ground surveys required in order to confirm ongoing population viabilities. Quantification of the numerous threats to the species (e.g. impacts of instream barriers, surface flow and groundwater reductions due to climate change and water extraction, riparian degradation, secondary salinisation and the presence of introduced species) is also required.

Item Type:	Journal Article
Murdoch Affiliation:	School of Veterinary and Life Sciences Centre for Fish and Fisheries Research Freshwater Fish Group & Fish Health Unit
Publisher:	Royal Society of Western Australia
Copyright:	© Royal Society of Western Australia 2014
URI:	http://researchrepository.murdoch.edu.au/id/eprint/35892

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