| Popis: |
Red porgies (Pagrus pagrus )o f 20.6� 1.5 g mean weight were reared in tanks under four delayed selffeeding conditions (0 5 control, 7, 30 and 90 s) after rod activation. The time intervals were chosen to simulate the time taken for a commercial pelleted feed to transit the tube linking a surface-mounted feed hopper and the depth at which a cage might be submerged. Daily feeding rate, growth, food conversion index and condition factor were quite similar but ¢sh behaviour diiered among conditions. Fish remained close to the feeding point in the ¢rst two treatments (0 and 7 s delay) but foraged more widely in the remaining treatments (30 and 90 s delay), only reconsolidating around the feeding point a few seconds before feed was released. Results are discussed in relation to learning capacity and adaptation of ¢sh to feeding behaviour £exibility, in order to develop reliable self-feeding systems suitable for submerged cages. |
