Voracious invader or benign feline? A review of the environmental biology of European catfish Silurus glanis in its native and introduced ranges* Gordon H Copp 1,2 , J Robert Britton 2 , Julien Cucherousset 2,3 , Emili Garcı ´a-Berthou 4 , Ruth Kirk 5 , Edmund Peeler 6 & Saulius Stak _ enas 7 1 Salmon & Freshwater Fisheries Team, Centre for Environment, Fisheries & Aquaculture Science, Pakefield Road, Lowestoft, Suffolk NR33 0HT, UK; 2 Centre for Conservation Ecology, School of Conservation Sciences, Bournemouth University, Fern Barrow, Poole, Dorset, BH12 5BB, UK; 3 EcoLab Laboratoire d’E ´ cologie Fonctionnelle, UMR 5245 (CNRS- UPS-INPT), Universite ´ Paul Sabatier, Ba ˆt. 4R3, 118, route de Narbonne, F-31062 Toulouse, Cedex 9, France; 4 Institute of Aquatic Ecology, University of Girona, E-17071 Girona, Spain; 5 School of Life Sciences, Kingston University, Penrhyn Road, Kingston upon Thames, Surrey KT1 2EE, UK; 6 Centre for Environment, Fisheries and Aquaculture Science, Weymouth, Dorset DT4 8UB, UK; 7 Department of Freshwater Ecology, Institute of Ecology of Vilnius University, Akademijos 2, LT-08412, Vilnius, Lithuania *This article ‘‘Voracious invader or benign feline? A review of the environment biology of European catfish Silurus glanis in its native and introduced ranges’’ was written by Gordon H Copp of Cefas-Lowestoft, J Robert Britton and Julien Cucherousset of Bournemouth University, Emili Garcı´a- Berthou of University of Girona, Ruth Kirk of Kingston University, Edmund Peeler of Cefas-Weymouth and Saulius Stak_ enas of Institute of Ecology of Vilnius University. It is published with the permission of the Controller of HMSO and the Queen’s Printer for Scotland. Abstract A popular species for food and sport, the European catfish (Silurus glanis) is well-studied in its native range, but little studied in its introduced range. Silurus glanis is the largest- bodied freshwater fish of Europe and is historically known to take a wide range of food items including human remains. As a result of its piscivorous diet, S. glanis is assumed to be an invasive fish species presenting a risk to native species and ecosystems. To assess the potential risks of S. glanis introductions, published and ‘grey’ literature on the species’ environmental biology (but not aquaculture) was extensively reviewed. Silurus glanis appears well adapted to, and sufficiently robust for, translocation and introduction outside its native range. A nest-guarding species, S. glanis is long-lived, rather sedentary and produces relatively fewer eggs per body mass than many fish species. It appears to establish relatively easily, although more so in warmer (i.e. Mediterranean) than in northern countries (e.g. Belgium, UK). Telemetry data suggest that dispersal is linked to flooding/spates and human translation of the species. Potential impacts in its introduced European range include disease transmission, hybridization (in Greece with native endemic Aristotle’s catfish [Silurus aristotelis]), predation on native species and possibly the modification of food web structure in some regions. However, S. glanis has also been reported (France, Spain, Turkmenistan) to prey intensively on other non-native species and in its native Germany to be a poor biomanipulation tool for top-down predation of zooplanktivorous fishes. As such, S. glanis is unlikely to exert trophic pressure on native fishes except in circumstances where other human impacts are already in force. In summary, virtually all aspects of the environmental biology of introduced S. glanis require further study to determine the potential risks of its introduction to novel environments. Keywords Diet, distribution, environmental impact, growth, habitat use, reproduction Correspondence: Gordon H Copp, Salmon & Freshwater Fisheries Team, Cen- tre for Environment, Fisheries & Aquacul- ture Science, Pakefield Road, Lowestoft, Suf- folk NR33 0HT, UK Tel.: +44 01502 527751 Fax: +44 01502 513865 E-mail: gordon.copp@ cefas.co.uk Received 9 May 2008 Accepted 12 November 2008 F I S H and F I S H E R I E S , 2009, 10, 252–282 252 DOI: 10.1111/j.1467-2979.2008.00321.x Ó 2009 Crown copyright