THE MURRAY-DARLING BASIN - PDF document

THE MURRAY-DARLING BASIN 103 AN INTRODUCTORY GUIDE 102 THE MURRAY-DARLING BASIN 103 AN INTRODUCTORY GUIDE 102 102 THE MURRAY-DARLING BASIN I ere is considerable confusion over the identication of ‘carp gudgeons’ in south- eastern Australia. Recent genetic studies have shown that at least four taxa are present, as well as a range of hybrids. In this book, carp gudgeons are treated as a group. All carp gudgeons are small and laterally compressed, with a truncate to slightly rounded tail. Maximum length 70 mm; usually around 40 mm. ey have two separate and distinct dorsal ns. e upper portion of their dorsal ns often develops and orange-red colour, bordered by a bluish- in breeding males. e back is yellowish-grey to greenish-brown and the scales of the upper sides and back have darker edges, giving a slightly reticulated appearance. e bluntness of the head prole, subtle colour variations, and presence of scales on the head and belly vary between the taxa. Biology and or still waters, normally associated with macrophyte beds or other aquatic vegetation. Two to four species of carp gudgeon often occur sympatrically. Early studies of reproduction in an unknown species of carp gudgeons recorded that spawning occurred when water temperature exceeded 22.5°C. Females may lay up to 2,000 small, (0.5 mm in shallow water and the eggs are deposited on submerged aquatic vegetation or twigs. e male guards and fans the eggs. Hatching occurs after about 50 hours, and newly hatched larvae are 1.8–2.1 mm long. e Western carp gudgeon is the only form present in Lake Burley Grin in the ACT and is primarily a mid-water carnivore although some benthic feeding also occurs. copepods, aquatic insects, cladocerans and ostracods, and chironomids are the most frequently consumed aquatic insect. Western carp gudgeon is abundant in the Canberra Common C Scientic Hypseleotris spp. NATI Photo: Gunther Schmida Murray- THE MURRAY-DARLING BASIN 103 AN INTRODUCTORY GUIDE 102 THE MURRAY-DARLING BASIN 103 AN INTRODUCTORY GUIDE 102 AN INTRODUCTORY GUIDE 103 region, in the urban lakes and Googong Reservoir, where it can form a substantial portion of the diet of Golden perch, Redn perch and Brown trout. Originally thought to be a relatively sedentary species, recent investigations have demonstrated that large numbers of carp gudgeons attempt to move through shways on the Murrumbidgee and Murray rivers. Whether these attempted movements reect local dispersal or foraging movements is unknown. Distribution and A As a group, carp gudgeons are widespread and common at mid to lower altitudes in the central and southern Basin, and up to 1000 m elevation in the northern Basin. ey are also found in coastal streams from central NSW to central Qld. e relative abundance of the various forms diers across the Basin. e Western carp gudgeon is now apparently rare in SA, but abundant and the only form found in the upper Murrumbidgee. However, they are not found in the Murrumbidgee River upstream of the ACT and in cold headwater streams generally. During the NSW Rivers Survey, carp gudgeons were the most and third most abundant native species recorded in the Darling and Murray catchments, respectively. Potential e group is widespread and abundant. However, in the ACT, signicant kills of Western carp gudgeon have occurred as a result of infestation with the introduced tapeworm Bothriocephalus acheilognathi . G Balcombe & Closs 2000, 2004; Baumgartner 2003; B ertozzi et al . 2000; Dove 1998; Dove et al . 1997; Larson & Hoese 1996a; MDBC 2004b; Stoels & Humphries 2003; acker & Unmack 2005; Unmack 2000. IVALL Avoca ivers Broken C C Central Murray C D G 10 G 11Kiewa 12Lachlan 13Loddon 14Lower Murray 15 16Mitta Mitta 17Murrumbidgee 18 N 19 O Paroo Upper Murray Warrego 23Wimmera Published by the Murray-Darling Basin Commission Postal address: GPO Box 409, Canberra ACT 2601 Oce 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 oce on (02) 6279 0100 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 is 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 benet 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. FISHES O F THE MURRAY-DARLING BASIN ii