Ewens Pygmy Perch, Nannoperca variegata Kuiter & Allen 1985


Other Names: Ewen Pygmy Perch, Variegated Pygmy Perch

Ewens Pygmy Perch, Nannoperca variegata. Source: Michael Hammer. License: All rights reserved

Summary:
Ewens Pygmy Perch has a restricted distribution, limited to the Glenelg river system in south-west Victoria and Ewens Ponds in South Australia. This small, slender bodied species varies in colour from pale tan to brownish, olive and orange but always with dark scale margins. Prefers swift flowing creeks with a good cover of vegetation.

Cite this page as:
Vanessa J. Thompson, Nannoperca variegata in Fishes of Australia, accessed 17 Nov 2018, http://fishesofaustralia.net.au/home/species/1830

Ewens Pygmy Perch, Nannoperca variegata Kuiter & Allen 1985

More Info


Distribution

Known only from coastal ponds and streams between Winnap, Victoria, and Ewens Ponds, South Australis. Inhabits small, swiftly flowing, cool freshwater creeks with abundant vegetation.

Features

Meristic features: Dorsal fin VIII-IX (usually VIII), 9-10; Anal fin III, 8-9; Pectoral fin 14-15; Pelvic fin I, 5; Causal fin 13-14.

Body relatively slender and laterally compressed, greatest depth 2.7-3.1 in SL; head relatively short, length 3.1-3.4 in SL; snout pointed, length 4.4-5.4 in HL; jaw reach back to front of pupil; jaws with numerous, slender villiform teeth; vomer and palatines with a band of villiform teeth; eye width 2.8-3.3 in HL; enlarged, paired nostrils on each side of snout, anterior nostrils with elevated rim, posterior twice size of anterior, above front of eye; small, inconspicuous sensory pores on each side of head; gill rakers poorly developed; margins of preorbital bone, preoperculum, and operculum smooth.

Scales on head and near midline of nape cycloid; body scales ctenoid; scales absent from anterior portion of nape, entire interorbital, snout, lips, chin, and fins; horizontal scale rows above lateral line at level of dorsal fin origin 3 (3 or 4), horizontal scale rows below lateral line at level of anal fin origin 8 (8 or 9); transverse scale rows on cheek 2 (2 or 3); lateral line an interrupted series of tubed scales

Single dorsal fin with an anterior spiny section and posterior soft section separated by deep notch, 1st dorsal spine about « (or slightly less) length of tallest (3rd) dorsal spine, dorsal spines gradually increasing in length to 3rd spine, then gradually decreasing, soft dorsal fin slightly lower than spinous dorsal, its maximum height about equal to distance from snout to rear edge of eye; anal fin opposite and similar to soft part of dorsal fin, 1st first anal spine about « (or slightly more) length of 2nd anal spine, 3rd anal spine about equal to 2nd anal spine; ventral and pectoral fins similar to each other in length; caudal fin moderately large, truncate or rounded.

Size

To 6.5 cm SL

Colour

Males are reddish-orange ventrally with a golden mid-lateral band and two primary rows of brown blotches along the side. Females are less brightly coloured, being mostly whitish ventrally with 2-3 rows of irregular brown blotches along the side. Both sexes have a brown band from the front of the eye to the snout and a golden sheen on the operculum. Juveniles are mainly pale olive grading to white ventrally with a dark mid-lateral stripe and black spot at the base of the caudal fin.

Feeding

Carnivore - feeds mainly on aquatic insects and benthic microcrustaceans.

Biology

Breeding occurs from spring to early summer and males become territorial during this period; females deposit small batches of eggs amongst aquatic vegetation or over the substrate every few days over several weeks. Non-adhesive, demersal eggs. Larave hatch after around 2-4 days.

Conservation

Listed as Vulnerable on the IUCN Red List of Threatened Species.
Listed as Vulnerable under the Australian EPBC Act.

Remarks

Often found around woody debris accumulated after a flood event. Co-occurs with Nannoperca australis in Ewen Ponds, South Australis, but generally prefers faster flowing streams rather than ponds

Similar Species

Nannoperca variegata is similar to N. australis but easily separated on the basis of colour pattern, predorsal scalation and counts for gill rakers and pectoral rays. They also differ in the number of predorsal bones with N. variegata having 4 compared to 3 for N. australis. Furthermore, there is also a difference in habitat with N. variegata preferring faster flowing water.

Etymology

Nannoperca means dwarf perch and comes from the Latin nannus meaning small, and the Greek perke meaning Perch. Species is named variegata in reference to the blotchy colour pattern.

Species Citation

Nannoperca variegata Kuiter, R.H. & Allen, G.R. (1985). A synopsis of the Australian pygmy perches (Percichthyidae), with the description of a new species. Rev. Fr. Aquariol. 12: 109-116 figs 1-12 [111]. Glengulin Creek, Winnap, VIC.

Author

Vanessa J. Thompson

Ewens Pygmy Perch, Nannoperca variegata Kuiter & Allen 1985

References


Allen, G.R., Midgley, S.H. & Allen, M. (2002). Field guide to the freshwater fishes of Australia.  Perthÿ: Western Australian Museum 394 pp.

Fisher, J.T. (1993). Action Statement No. 42 Variegated (Ewen's) Pygmy Perch Nannoperca variegata. [Online]. Melbourne: Dept. Natural Resources & Environment. Available from: http://www.nre.vic.gov.au/web/root/domino/cm_da/nrenpa.nsf/frameset/NRE+Plants+and+Animals?OpenDocument.

Growns I. (2004). A numerical classification of reproductive guilds of the freshwater fishes of south-eastern Australia and their application to river management. Fisheries Management and Ecology 11: 369?377.

Koehn, J.D. & W.G. O'Connor (1990). Biological Information for the Management of Native Freshwater Fish in Victoria. ARI, Victoria. Dept CFL, Victoria.

Kuiter, R.H. & Allen, G.R. (1985). A synopsis of the Australian pygmy perches (Percichthyidae), with the description of a new species. Rev. Fr. Aquariol. 12: 109?116

McDowall, R.M. ed (1996). Freshwater Fishes of South-Eastern Australia rev. edn. Chatswood, NSW: Reed Books.

Wager, R. & P. Jackson (1993). The Action Plan For Australian Freshwater Fishes. Canberra, ACT: Australian Nature Conservation Agency.

Quick Facts


CAAB Code:37323009

Conservation:EPBC Act & IUCN - Vulnerable

Habitat:Freshwater

Max Size:6.5 cm

Native:Endemic

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