I & I NSW WILD FISHERIES RESEARCH PROGRAM Catfish (Siluriformes) EXPLOITATION STATUS UNDEFINED Several species of catfishes are harvested at low levels in NSW estuaries by both commercial and recreational fishers. Very little information is available to establish exploitation status. SCIENTIFIC NAME STANDARD NAME COMMENT Cnidoglanis macrocephalus estuary cobbler The major component of catches. Euristhmus lepturus longtail catfish Minor component of catches. Plotosus lineatus striped catfish Small species infrequently caught. Arius graeffei blue catfish Also known as forktailed catfish. Cnidoglanis macrocephalus Image © Bernard Yau Background is apparently rare in Victorian and Tasmanian In NSW, catfish are typically low-value, non- waters. They inhabit estuaries and inshore target species with virtually all the landed coastal waters to a depth of about 30 m. catch (20-30 t per year) taken by mesh nets in the Estuary General Fishery. Commercial Estuary cobblers grow to about 75 cm in length landings are dominated by the estuary cobbler and a weight of 2.5 kg. In NSW, they were found (Cnidoglanis macrocephalus) but the catch to mature at a length of 45-50 cm at an age of also includes small numbers of long-tailed 2 to 3 years, and recent studies indicate that (Euristhmus lepturus), striped (Plotosus lineatus), they can live up to 20 years. Peak spawning was and blue (Arius graeffei) catfishes. found to occur in spring and summer. In WA, estimates of fecundity ranged from 500 - The estuary cobbler is an eeltail catfish 3,500 eggs. Estuary cobblers have a large belonging to the family Plotosidae. As the serrated spine on their dorsal and pectoral fins name suggests, catfishes of this family have - these spines are poisonous and capable of long tapering tails similar to an eel. The inflicting a painful wound. estuary cobbler is endemic to Australia being found around most of the southern half of The longtail and striped catfishes are also eeltail the continent between southern Queensland catfishes but have more tropical distributions and southern NSW, and from SA to the than the estuary cobbler. The longtail catfish, Houtman Abrolhos Islands in WA; the species which can attain a length of 46 cm, is found in STATUS OF FISHERIES RESOURCES IN NSW, 2008/09 Catfish | P 65 WILD FISHERIES RESEARCH PROGRAM estuarine and near-coastal waters of northern Catch Australia and southern New Guinea. Striped catfish, which commonly form small dense Recreational Catch of Catfish schools or ‘balls’, are found throughout the The annual recreational harvest of catfish in Indo-Pacific, inhabiting fresh to marine waters NSW is likely to lie between 30 and 50 t. This up to 60 m deep. They attain a maximum estimate is based upon the results of the offsite length of about 30 cm and an age of 7 years; a National Recreational and Indigenous Fishing Japanese study estimated their age at maturity Survey (Henry and Lyle, 2003) and onsite to be 1-3 years, at a length of about 14 cm total surveys undertaken by I & I NSW. It is probable length (TL). that large numbers of catfish are discarded by The blue catfish belongs to the large tropical recreational fishers as they are not generally family of forktail catfishes (Ariidae). Forktail seen as a desirable catch. catfishes primarily inhabit freshwater, estuarine and inshore coastal waters, and are important Historical Landings of Catfish food fishes in Asia. A characteristic of the family is that the eggs and larvae are incubated 40 in the mouths of the male parent, but their low fecundity makes them susceptible to overfishing. Blue catfish inhabit rivers, estuaries 30 and shallow coastal waters of northern Australia and southern New Guinea and attain a maximum length of 50 cm TL; small numbers 20 are caught in the estuarine parts of NSW rivers, Landings (t) north from the Clarence River. 10 Historically, the catfish species have not been differentiated in commercial catch returns, 0 however from 2009/10 eeltailed and forktailed 90/91 92/93 94/95 96/97 98/99 00/01 02/03 04/05 06/07 08/09 catfish will be separately recorded. Financial Year Commercial landings (including available historical records) of catfish for NSW from 1990/91 to 2008/09 for Additional Notes all fishing methods. • Commercial landings of ‘catfish’ are stable at 20 - 30 t. Recreational landings are likely to be of a similar magnitude, but are not accurately Landings by Commercial Fishery of Catfish estimated. • Estuary catfish or estuary cobbler Cnidoglanis( Estuary General macrocephalus) is more commonly marketed * Estuary Prawn Trawl (Byproduct Species) than forktailed catfish (Arius graeffei), which are a bycatch species in the Clarence River 40 Estuary Prawn Trawl. 30 • A growth curve for C. macrocephalus is now available, indicating that the species can live 20 up to 20 years. Landings (t) • Commercial catch returns now segregate 10 catfish into two groups: forktail catfish (‘Ariidae - undifferentiated’); and eeltail 0 catfish (‘Plotosidae – undifferentiated’). 97/98 99/00 01/02 03/04 05/06 07/08 Financial Year Reported landings of catfish by NSW commercial fisheries from 1997/98. * Fisheries which contribute less than 2.5% of the landings are excluded for clarity and privacy. P 66 | Catfish STATUS OF FISHERIES RESOURCES IN NSW, 2008/09 Catch Per Unit Effort Information of Catfish Further Reading Harvested by Mesh-Netting in NSW Allen, G.R. (1997). Marine Fishes of Tropical Australia and South-East Asia. Perth, West Australian 1.0 Museum. 0.8 Blaber, S.J.M., D.P. Cyrus, J.J. Albaret, C.V. Ching, J.W. Day, M. Elliott, M.S. Fonseca, D.E. Hoss, J. Orensanz, I.C. Potter and W. Silvert (2000). Effects of fishing 0.6 on the structure and functioning of estuarine and nearshore ecosystems. ICES Journal of Marine Science 0.4 57 (3): 590-602. Relative Catch Rate Gray, C.A., S.J. Kennelly and K.E. Hodgson (2003). Low 0.2 levels of bycatch from estuarine prawn seining in New South Wales, Australia, Fisheries Research 0.0 64 (1): 37-54. 98/99 00/01 02/03 04/05 06/07 08/09 Financial Year Henry, G.W. and J.M. Lyle (2003). The National Recreational and Indigenous Fishing Survey. Final Catch rates of catfish harvested using mesh-netting for Report to the Fisheries Research & Development NSW. Two indicators are provided: (1) median catch rate (lower solid line); and (2) 90th percentile of the catch Corporation and the Fisheries Action Program rate (upper dashed line). Note that catch rates are not a Project FRDC 1999/158. NSW Fisheries Final Report robust indicator of abundance in many cases. Caution Series No. 48. 188 pp. Cronulla, NSW Fisheries. should be applied when interpreting these results. Kuiter, R.H. (1993). Coastal Fishes of South-Eastern Australia. Honolulu, University of Hawaii press. Neira, F.J., A.G. Miskiewicz and T. Trnski (1998). Larvae Growth CurveEstuary of Estuary Cobbler (Cnidoglanis Cobbler macrocephalus) of Temperate Australian fishes. Nedlands, WA, University of Western Australia Press. 70 Nel, S.A., I.C. Potter and N.R Loneragan (1985). The Biology of the catfish Cnidoglanis macrocephalus 60 (Plotosidae) in an Australian Estuary. Estuarine, Coastal and Shelf Science 21: 895-909. 50 Platell, M.E., P.A. Orr and I.C. Potter (2006). Inter- and intraspecific partitioning of food resources by six TL (cm) 40 large and abundant fish species in a seasonally open estuary. Journal of Fish Biology 69 (1): 243-262. 30 Potter, I.C., N.R. Loneragan, R.C.J. Lenanton, P.J. Chrystal and C.J. Grant (1983). Abundance, distribution and age structure of fish populations in 20 a Western Australian estuary. Journal of Zoology 200 (1): 21-50. 0 5 10 15 20 Age (years) Yearsley, G.K., P.R. Last and R.D. Ward (1999). Australian Seafood Handbook. Hobart, CSIRO Marine Research. Age-length data with fitted growth curve for estuary cobbler (internal data). Lengths are presented as total length (TL). Please visit the CSIRO website, http://www.marine.csiro.au/caab/ and search for the species code (CAAB) 37 192001, 37 192004, 37 192002 and 37 188005, common name or scientific name to find further information. © State of New South Wales through Industry and Investment NSW 2010. You may copy, distribute and otherwise freely deal with this publication for any purpose, provided that you attribute Industry and Investment NSW as the owner. Disclaimer: The information contained in this publication is based on knowledge and understanding at the time of writing (April 2010). However, because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currency of the information with the appropriate officer of Industry and Investment NSW or the user’s independent adviser. Catfish | P 67 WILD FISHERIES RESEARCH PROGRAM P 68 | Catfish.