The apparent gross conversion efficiency (GCE, DM:DM) until 144 hah was significantly dependent on feeding level (P=0.0006), but was not influenced by the fish density (P=0.9301) or by the interaction between the two factors (P=0.2583; Fig. 7). At all fish densities, the GCE was highest (≥0.35) at 1 RFL, and decreased
significantly at higher levels (except between 1 and 3 RFL at 90 fish L−1).