Yarra Pygmy Perch, Nannoperca obscura (Klunzinger 1872)


Yarra Pygmy Perch, Nannoperca obscura. Source: Michael Hammer. License: All rights reserved

Summary:

A small, freshwater fish endemic to southern Australia where it is patchily distributed in Victoria and South Australia. Yarra Pygmy Perch are olive-green above, greenish-brown on the sides and yellowish-white below with chevron-shaped markings on rear half of the body. The serrated lower edge of the pre-orbital bone is exposed. 

The species was described from the 'Yarra Lagoon, near Melbourne'. Unfortunately, Yarra Pygmy Perch are now extinct in the Yarra River.


Cite this page as:
Bray, D.J. & Thompson, V.J. 2018, Nannoperca obscura in Fishes of Australia, accessed 20 Nov 2018, http://fishesofaustralia.net.au/home/species/4459

Yarra Pygmy Perch, Nannoperca obscura (Klunzinger 1872)

More Info


Distribution

Endemic to temperate waters of the Bunyip River system, Victoria, westwards to the Finniss River, Bool Lagoon and Lake Alexandrina in eastern South Australia.

Populations that once inhabited the Yarra River and Dandenong Creek near Melbourne, are now presumed extinct. Remaining populations have become fragmented due to water regulation and habitat loss.

Yarra Pygmy Perch inhabit freshwater streams and lakes with still or slow-moving waters, such as  lakes, or pools in rivers and streams - preferring areas with abundant submerged and emergent aquatic vegetation, often in streams with woody debris.

Features

Dorsal fin  VIII-IX, 7-9 (usually IX, 9); Anal fin III, 6-7; Pectoral fin 11-13 (usually 12).

Body oblong, compressed; dorsal profile more strongly arched than ventral profile; head large, dorsal profile straight; snout pointed; eye of moderate size, dorsolateral; mouth small, terminal, slightly oblique, protractile; jaw reaches back to front of eye; jaws, vomer and palatines with narrow bands of villiform teeth; lower, free edge of preorbital bone straight, strongly serrated; numerous distinct pores on head and operculum.

Scales moderately-large, finely ctenoid without circular ridges; scales present on head, opercula and cheeks; lateral line of interrupted series of tubed scales; mid-lateral scales 28-30; transverse scale rows 12-13.

A single dorsal fin with an anterior spiny section and posterior soft section separated by deep notch; anal fin opposite and similar to soft part of dorsal fin; pectoral fins small, rounded, positioned low on sides; ventral fins small, pointed, set well forward on abdomen; caudal fin moderately large, truncate or rounded.

Size

To 7.5 cm SL, commonly to 5cm.

Colour

Olive green above, greenish-brown laterally, yellowish-white below, with darker scale margins and a faint reticulate pattern. Opercular region with golden sheen. Several dark blotches mid-laterally. Fins clear, fawn to orange, often with dark margins; pelvic and anal fins often with dark anterior edge. Caudal peduncle with a dark spot.
Prior to spawning, the pelvic fins of the male become black, the leading edge of the anal fin darkens and the dorsal and anal fins become an intense brownish-orange.

Feeding

Carnivore - feeds mostly on insect larvae, molluscs and microcrustaceans.

Biology

Little is known of the biology of this species. Spawning occurs in September to October at water temperatures between 16 and 24°C.

Like other pygmy perches, this species presumably spawns large demersal eggs amongst aquatic vegetation.

Conservation

IUCN Red List: Vulnerable

EPBC Act 1999: Vulnerable

Victorian Flora and Fauna Guarantee Act 1988: Threatened

Populations of Yarra Pygmy Perch have declined in recent decades, due to habitat loss and predation by, and competition with introduced species such as Redfin (Perca fluviatilis) and Brown Trout (Salmo trutta).

Remarks

Yarra Pygmy Perch form small shoals, often mixing with Southern Pygmy Perch, Nannoperca australis.

As the scientific name implies, Yarra perch were originally described from 'Yarra Lagoon, near Melbourne'. Unfortunately, the species is now extinct in the Yarra River.

Similar Species

The Yarra Pygmy Perch differs from the Southern Pygmy Perch, Nannoperca australis, in having a smaller mouth, a serrated preorbital bone and in having a slightly notched pupil rather than one which is round. Fins of breeding males turn black compared with the bright red fins of N. australis.

Etymology

Nannoperca, meaning 'dwarf perch', is from the Latin nannus meaning 'small', and the Greek perke meaning 'perch'. The species name obscura is from Latin meaning 'darkened' in reference to the dark fins of breeding males.

Species Citation

Paradules obscurus Klunzinger, 1872, Arch. Naturg. 38(1): 20. Type locality: Yarra lagoon, Melbourne, VIC.

Author

Bray, D.J. & Thompson, V.J. 2018

Resources

 Australian Faunal Directory

Yarra Pygmy Perch, Nannoperca obscura (Klunzinger 1872)

References


Allen, G.R. 1989. Freshwater Fishes of Australia. Neptune, New Jersey : T.F.H. Publications 240 pp., 63 pls. 

Allen, G.R., Midgley, S.H. & Allen, M. 2002. Field Guide to the Freshwater Fishes of Australia. Perth : Western Australian Museum 394 pp.

Brauer CJ, Unmack PJ, Hammer MP, Adams M, Beheregaray LB (2013) Catchment-Scale Conservation Units Identified for the Threatened Yarra Pygmy Perch (Nannoperca obscura) in Highly Modified River Systems. PLoS ONE 8(12): e82953. Open Access doi:10.1371/journal.pone.0082953

Cadwallader, P.L. & Backhouse, G.N. 1983. A Guide to the Freshwater Fish of Victoria. Melbourne : F.D. Atkinson Government Printer 249 pp. figs.

Carvalho, D., Rodriguez-Zarate, C., Hammer, M. & Beheregaray, L. 2011. Development of 21 microsatellite markers for the threatened Yarra pygmy perch (Nannoperca obscura) through 454 shot-gun pyrosequencing. Conservation Genetic Resources 3: 601–604. doi: 10.1007/s12686-011-9413-8

Castelnau, F.L. de 1872. Contribution to the ichthyology of Australia. 1. The Melbourne fish market. Proceedings of the Zoological and Acclimatisation Society of Victoria 1: 29-242 1 pl.

Crook, D., Macdonald, J., Belcher, C., O’Mahony, D., Dawson, D., Lovett, D., Walker, A. & Bannam, L. 2008. Lake Condah Restoration Project – Biodiversity Assessment. Arthur Rylah Institute for Environmental Research Technical Report Series No. 180, Department of Sustainability and Environment, Heidelberg, Victoria.  

Donnelly, A.J. & Grieves CJ. 1992. Yarra Pigmy Perch (Edelia obscura) in the Fitzroy River, South Western Victoria. Victorian Naturalist 109(2): 54-55.  

Hammer, M.P., Unmack, P.J., Adams, M., Johnson, J.B. & Walker, K.F. 2010. Phylogeographic structure in the threatened Yarra pygmy perch Nannoperca obscura (Teleostei: Percichthyidae) has major implications for declining populations. Conservation Genetics 11: 213–223 

Hammer, M.P. & Walker, K.F. 2004. A catalogue of South Australian freshwater fishes, including new records, range extensions and translocations. Transactions of the Royal Society of South Australia 128(2): 85-97

Jones, M., Tinkler, P., Lindeman, M., Hackett, G., & Pickworth, A. 2008. Threats, distribution and abundance of Yarra Pygmy Perch in Victoria during a drought period. Arthur Rylah Institute for Environmental Research Technical Report Series No. 184, Department of Sustainability and Environment, Heidelberg, Victoria.  

Klunzinger, C.B. 1872. Zur Fische-fauna von Süd Australien. Archiv für Naturgeschichte 38(1): 17-47 pl. 2 (p. 20, as Paradules obscurus)  

Koehn, J.D. & Morison, A.K. 1990. A review of the conservation status of native freshwater fish in Victoria. Victorian Naturalist 107(1): 13-25.  

Kuiter, R.H. 2013. Pictorial Guide to Victoria's Freshwater Fishes. Seaford, Victoria : Aquatic Photographics 178 pp. 

Kuiter, R.H. & Allen, G.R. 1986. A synopsis of the Australian pygmy perches (Percichthyidae), with the description of a new species. Revue Française d'Aquariologie et Herpétologie 12(4): 109-116 

Kuiter, R.H., Humphries, P.A. & Arthington, A.H. 1996. Family Nannopercidae. pp. 168-175 in McDowall, R.M. (ed.) Freshwater Fishes of South-eastern Australia. Sydney : Reed Books 247 pp.

Lake, J.S. 1971. Freshwater Fishes and Rivers of Australia. Melbourne : Nelson 61 pp. 

Lake, J.S. 1978. Australian Freshwater Fishes. Melbourne : Thomas Nelson 160 pp. 140 figs. 

Leggett, R. & Merrick, J.R. 1987. Australian Native Fishes for Aquariums. Artarmon : J.R. Merrick Publications 241 pp. 142 figs. 

Lintermans, M. 2009. Fishes of the Murray-Darling Basin — An Introductory Guide. Canberra : Murray-Darling Basin Commission 157 pp. 

McDowall, R.M. (ed.) 1980. Freshwater Fishes of South-eastern Australia. Sydney : A.H. & A.W. Reed 208 pp., figs, 32 pls. 

Merrick, J.R. & Schmida, G.E. 1984. Australian Freshwater Fishes Biology and Management. Sydney : J.R. Merrick 409 pp. figs 280 col. figs.

Prosdocimi, F., de Carvalho, D.C., de Almeida, R.N. & Beheregaray, L.B. 2012. The complete mitochondrial genome of two recently derived species of the fish genus Nannoperca (Perciformes, Percichthyidae). Mol. Biol. Rep. 39(3): 2767-2772.  

Saddlier, S. & Hammer, M. 2010. National Recovery Plan for the Yarra Pygmy Perch (Nannoperca obscura). East Melbourne, Victoria: Department of Sustainability and Environment. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/recovery/yarra-pygmy-perch.html.  

Saddlier, S., Koehn, J. & Hammer, M. 2013. Lets not forget the small fishes – conservation of two threatened species of pygmy perch in south-eastern Australia. Marine and Freshwater Research 64: 874–886. doi: 10.1071/mf12260  

Sanger, A.C. 1978. Aspects of the ecology and evolution of the Pigmy perches (Teleostei : Kuhlidae). Honours Thesis, Department of Zoology, Melbourne University, Parkville. 98 pp.  

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Unmack, P.J., Hammer, M.P., Adams, M. & Dowling, T.E. 2011. A phylogenetic analysis of pygmy perches (Teleostei: Percichthyidae) with an assessment of the major historical influences on aquatic biogeography in southern Australia. Systematic Biology 60(6): 797–812 doi: 10.1111/mec.12204   

Wager, R. 1996. Nannoperca obscura. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1. . Downloaded on 24 March 2012.

Quick Facts


CAAB Code:37323007

Conservation:EPBC Act Vulnerable; IUCN Vulnerable

Habitat:Freshwater

Max Size:7.5 cm

Native:Endemic

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CAAB distribution map