Growth differences between naturally recruited and stocked European eel Anguilla anguilla from different habitats in Lithuania

European eels Anguilla anguilla from freshwater lakes in Lithuania had slower growth rates and lower backcalculated total lengths (LT) than those from lagoons and coastal waters, but no significant differences were found among fish with different migratory histories or between naturally recruited and stocked fish except a higher L-T at age of stocked European eels at ages 5 to 8 years. The asymptotic L-T (L-T infinity ) did not differ among habitats or migratory histories, but the stocked eels in the lakes had smaller K (coefficient from the von Bertalanffy growth function) than did the both naturally recruited and stocked eels in the lagoon and coastal waters. The growth rate of European eels in Lithuania might be influenced mainly by different habitats rather than different migratory histories and stocking. The lower LT at age of naturally recruited fish at ages 5-8 years compared to stocked fish might result from the extra energy costs entailed in migration from the Atlantic and across the Baltic Sea. (C) 2007 The Authors.