NATIVE

Common Name Freshwater (Jewfish, Eeltail catfish) Declining

Scientific Name tandanus Mitchell, 1838 Photo: Gunther Schmida

Identification is a circular to oval depression, 0.6–2.0 m A medium sized species with a laterally in diameter, constructed from pebbles and compressed rear portion of the body. gravel, with coarser material in the centre. The Maximum length 900 mm and maximum eggs are large (~3 mm), non-adhesive, settle size 6.8 kg; usually < 500 mm and < 2 kg. into the interstices of the coarse substrate, and The head is large and four pairs of barbels take up to seven days to hatch. The male fish surround the large mouth, with its thick remains with the nest to fan, clean and guard fleshy lips. The first is short but the eggs. It has been suggested that there may high, just behind the head, and has a stout, be multiple spawnings in a single nest in a serrated spine at the front of the fin. The season, either sequentially or concurrently. second dorsal fin is continuous with the Larvae are about 7 mm long at hatching. caudal and anal fins, hence the species’ The Freshwater catfish is a relatively sedentary alternative common name of -tailed species and adults show very limited catfish. The skin is smooth, with no scales. movement compared to cod and perch; most The back of adults is usually olive-green individuals move less than 5 km. This catfish to brown, and the belly whitish. Juveniles is predominantly an opportunistic carnivore tend to be grey-brown, mottled with darker and the adult diet consists mainly of shrimps, blotches. freshwater prawns and yabbies, with aquatic insects, snails and small fishes also important. Biology and Habitat Aquatic insects are more important in the diet Freshwater catfish is a benthic species that of juvenile fish. Adults are mostly active at prefer slow-flowing streams and lake habitats. dusk and in the early evening. Individuals are sexually mature at 3–5 years of age and spawn in spring and summer when water temperatures are 20–24°C. The nest

56 Fishes of the Murray-Darling Basin An introductory guide 57 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

Distribution and Abundance and Redfin perch on riverine populations. This catfish is widespread throughout the Cold-water pollution below dams, barriers to Murray-Darling Basin, but generally in movement, changes to natural flow regimes the lower, slow-flowing rivers. It (and a and elevated salinity levels (juveniles have number of suspected cryptic species) is also much lower salinity tolerance than adults), found in coastal rivers from southern NSW are also suspected as causes of declining local to northern Qld. It has been stocked into populations. The lack of formal recognition some farm dams and lakes where it can as a threatened species has hampered establish breeding populations. Most riverine conservation efforts. populations have declined significantly since General References the late 1970s/early 1980s, and the species is no longer common in many areas where it Clunie & Koehn 2001a,b; Davis 1977a,b,c; was formerly abundant. Some populations Pollard et al. 1996; Pusey et al. 2004; Morris in impoundments seem to be faring better. et al. 2001; Reynolds 1983. The species was relatively abundant in the Qld portion of the Basin until recently. It is still common in the upper Condamine River but has disappeared from the Paroo and is now in relatively low numbers in the lower Condamine and Warrego rivers.

Potential Threats Numerous threats have contributed to the decline in this species. Concern has been expressed about the potential impacts of Carp

56 Fishes of the Murray-Darling Basin An introductory guide 57 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: [email protected] 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.

ii Fishes of the Murray-Darling Basin