Swim fitness of European eel (Anguilla anguilia)

摘要: European silver eels migrate 5500-km to their assumed spawning grounds in the Sargasso Sea. We found that swim 4–6 times more efficient than non eel-like fish and utilise ca. 60 g fat per kg for migration. In order be able compare performance of from different locations under conditions we developed a fitness test. Swim trials with 162 female weighing 200–1500 were performed 22 Blazka-type swimtunnels climatised room at 18 -C running fresh or salt water. Speed endurance started 0.5 up 1 meter per second (m/s) increments 0.1 m/s. Eels reached maximum aerobic speeds 1.64 body-length second (BL/s). Although they did not fast, swam almost equally all between 1.5 BL/s. Both maximum optimum lower in silver yellow eels. Absolute m/s cost transport similar since bigger. A single day test was discriminate good poor swimmers. For infection swim-bladder parasite Anguillicola crassus, negative correlation pressure speeds. positive bladder damage transport. Thus it is clear reduces capacity long distance migration