F i s h e s o F t h e M u r r ay- Da r l i n g B a s i n 85An introductory guide84 F i s h e s o F t h e M u r r ay- Da r l i n g B a s i n 85An introductory guide8484 F i s h e s o F t h e M u r r ay- Da r l i n g B a s i n

identificationA small to medium sized, laterally compressed fish with a relatively slender body for a grunter. Maximum size 330 mm; rarely 250 mm and 560 g; commonly 150 mm. The single dorsal fin has a moderately sized notch between the spinous and soft-rayed portions. The pelvic fins are inserted behind the origin of the pectoral fins. The anal and pelvic fins are white. The back is generally brown to steely-blue and the sides silvery-grey with numerous bronze to rusty-brown spots. The tail is slightly forked, the eye is small to moderate, and the mouth is of moderate size with equal jaws.

Biology and habitatThe Spangled perch is a hardy species that is well adapted to surviving in diverse environments such as rivers, billabongs, lakes, isolated dams, bore-drains, wells and waterholes in intermittent streams. It can survive temperatures up to 40°C, but doesn’t like the cold, with a lower lethal limit of around 4.1°C and markedly lower survival

below 7.2°C. It has admirable dispersal abilities which allows it to rapidly colonise habitats not readily accessible to other fish species. During heavy rain it has been observed swimming across flooded paddocks and along wheel ruts on tracks.

Individuals mature in their first year, males at about 58 mm length and females at 78 mm. Breeding occurs from November to February and fecundity is high and size-dependant, with between 24,000 and 113,200 eggs per female. Spawning occurs when water temperatures are above 20–22°C and a rise in water level is not essential as the species will breed in impoundments. However, flooding maximises recruitment. Spawning occurs at night, in shallow areas such as backwaters or still pools and eggs are spread randomly over the bottom. The eggs are small (0.7 mm), round, demersal and non-adhesive and hatch in 45–55 hrs at 23–26°C.

Movement can be associated with spawning or dispersal, and fish move rapidly upstream, downstream or laterally in flooded environments. The Spangled perch feeds

Common name Spangled perch (Spangled grunter, Jewel perch)

scientific name Leiopotherapon unicolor (günther, 1859)

natiVe sPeCies

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mainly during daylight hours and is primarily a carnivore, although it consumes some plant material (~10 % of diet). Aquatic insects, shrimps and prawns, microcrustaceans and fish are important components of the diet, with the relative importance varying between studies and locations.

Distribution and abundanceThe Spangled perch is Australia’s most widespread native freshwater fish, occurring across most of northern Australia. In the Murray-Darling Basin it occurs on the north and western portions, essentially north of Condoblin. It is rare in southern waters of the Basin (down to the Murray), and is recorded in such areas only after extensive flooding in northern rivers. It is not known from the ACT or Vic. Cold winter water temperatures are thought to limit its distribution. This perch can be very abundant, especially after flooding, but this varies with seasonal conditions.

Potential threatsSpangled perch has lower abundance in regulated rivers, with aspects of river regulation such as cold-water pollution, barriers to fish movement, reduced flooding and access to floodplains likely to disadvantage it.

general referencesAllen et al. 2002; Beumer 1979b,c; Bishop et al. 2001; Bostock et al. 2006; Harris & Gehrke 1997; Llewellyn 1973; Medeiros 2004; Merrick 1996; Merrick & Schmida 1984; Pusey et al. 2004.

iD VALLey 1 Avoca 2 Border rivers 3 Broken 4 campaspe 5 castlereagh 6 central Murray 7 condamine 8 darling 9 goulburn 10 gwydir 11 Kiewa 12 Lachlan 13 Loddon 14 Lower Murray 15 Macquarie 16 Mitta Mitta 17 Murrumbidgee 18 namoi 19 ovens 20 Paroo 21 upper Murray 22 Warrego 23 Wimmera

iD VALLey 1 Avoca 2 Border rivers 3 Broken 4 campaspe 5 castlereagh 6 central Murray 7 condamine 8 darling 9 goulburn 10 gwydir 11 Kiewa 12 Lachlan 13 Loddon 14 Lower Murray 15 Macquarie 16 Mitta Mitta 17 Murrumbidgee 18 namoi 19 ovens 20 Paroo 21 upper Murray 22 Warrego 23 Wimmera

Published by the Murray-Darling Basin Commission Postal address: GPO Box 409, Canberra ACT 2601 Office location: Level 3, 51 Allara Street, Canberra City ACT Telephone: (02) 6279 0100, international + 61 2 6279 0100 Facsimile: (02) 6248 8053, international + 61 2 6248 8053 Email: info@mdbc.gov.au Internet: http://www.mdbc.gov.au

For further information contact the Murray-Darling Basin Commission office on (02) 6279 0100

This fish fact sheet is an extract derived from the report: Lintermans, M. 2007, Fishes of the Murray-Darling Basin: An introductory guide.

MDBC Publication No. 10/07

ISBN 1 921257 20 2

© Murray-Darling Basin Commission 2007

This work is copyright. Graphical and textual information in the work (with the exception of photographs, artwork and the MDBC logo) may be stored, retrieved and reproduced in whole or in part provided the information is not sold or used for commercial benefit and its source (Fishes of the Murray-Darling Basin) is acknowledged. Such reproduction includes fair dealing for the purpose of private study, research, criticism or review as permitted under the Copyright Act 1968. Reproduction for other purposes is prohibited without the permission of the Murray-Darling Basin Commission or the individual photographers and artists with whom copyright applies.

To extent permitted by law, the copyright holders (including its employees and consultants) exclude all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this report (in part or whole) and any information or material contained in it.

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