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 101An introductory guide100 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 101An introductory guide100100 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

identificationAn attractive, small, robust fish with a rounded head, small mouth, and gape that extends to the anterior margin of the eye. Maximum size 152 mm; commonly 60–120 mm. The tail is rounded, and there are two dorsal fins, the first short-based and lower than the longer and taller second dorsal. The back is dark brownish to yellowish brown (but can be iridescent blue in general with a series of blue blotches towards the tail), fading to lighter brown or cream on the belly. A row of darkish blotches are present on the sides from the start of the second dorsal fin to the start of the caudal fin, surrounded by numerous red and white spots. Males have 3–4 brown-to-purple facial stripes extending from behind the eye to the back of the operculum. Females generally have two stripes, which are less prominent. There are numerous red spots on the dorsal, anal and caudal fins.

Biology and habitatThe Southern purple-spotted gudgeon is a slow-moving ambush predator, consuming

small fish and aquatic macroinvertebrates and also worms and tadpoles. It is a benthic species, usually associated with good cover such as cobble and rocks in the Queensland parts of its range, or aquatic vegetation in its southern range. It is found in slow moving or still waters of creeks, rivers, wetlands and billabongs, and prefers slower flowing, deeper habitats.

Males mature at 45 mm and females at 49 mm. The male has an elaborate courtship display and pairing and spawning occurs in summer when water temperature exceeds 20°C. Females can spawn several times during a spawning season. The eggs are adhesive and 280–1300 are deposited in a single batch on a rock, log or aquatic plants. The eggs are elongate, pointed at both ends, transparent and 1.0–1.3 mm wide and 2.0–3.8 mm long. The male stays to guard and fan the eggs, which hatch after 3–9 days depending on water temperature. Newly hatched larvae are approximately 4 mm long.

Common name Southern purple-spotted gudgeon (Purple-spotted gudgeon)

threatened

scientific name Mogurnda adspersa (castelnau, 1878)

natiVe sPeCies

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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 101An introductory guide100 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 101An introductory guide100 An introductory guide 101

Purple-spotted gudgeons are carnivorous, obtaining food from the benthos, the water column and the water surface.

Distribution and abundanceThis gudgeon is present in coastal streams of northern NSW and Qld as well as the Murray-Darling Basin. In the Basin it has undergone a significant decline and is now presumed extinct in SA (where a single translocated population occurs) and Vic. It is patchily distributed and rare in northern NSW, but still locally abundant in the Border Rivers, Moonie River and Condamine-Balonne system in Qld. A new population was recently discovered in the Macquarie catchment in NSW. It was formerly patchily distributed in the Murrumbidgee, Lachlan and Murray rivers and tributaries of the Darling in NSW; and tributaries of the Murray and Wimmera rivers in Vic. Records in the mid 1990s from the Cardross Lakes near Mildura were the first from Vic in more than 50 years, but recent surveys of this lake system have failed to relocate the species.

Potential threatsThe precise reasons for the decline of this species are unknown, but interactions with alien species (particularly Eastern gambusia and Redfin perch), and fluctuations in water levels with river regulation, are thought to be significant.

general referencesBoxall et al. 2002; Cadwallader & Backhouse 1983; Hamlyn-Harris 1931; Hansen 1988; Larson & Hoese 1996a; Merrick & Schmida 1984; Moffat & Voller 2002; Morris et al. 2001; Raadik 1995; Raadik & Harrington 1996.

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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