Evaluation of selected feeds differing in dietary lipids levels in feeding juveniles of wels catfish, <I>Silurus glanis</I> L.

Development of modern aquaculture and the increasing consumer demand provoke improvements in the complex breeding technologies of economically valuable fish species. Wels catfish, Silurus glanis L. (known also as the European catfish), because of its breeding and consumption values, becomes an increasingly common object of breeding. The pond breeding technology of the catfish was developed in the early 20th century in Hungary and it was later adopted in Germany, Russia, Czech Republic, Slovakia, and Poland, reaching France relatively recently (Vallod 1987, Proteau et al. 1996). Now the wels catfish is cultured in the circulation systems, substantially shortening the production cycle (from hatch to a market-size fish of about 1.5 kg) to the period of 7–8 months (Ulikowski et al. 1998, Linhart et al. 2002, Ulikowski 2003, 2005). The improvement of fish feeding was another direction of the catfish breeding technology improvement, focusing on optimization of the content of proteins, fats, carbohydrates, vitamins, amino acids (essential ones ACTA ICHTHYOLOGICA ET PISCATORIA (2008) 38 (2): 91–96 DOI: 10.3750/AIP2008.38.2.02