Digestibility of protein and energy were determined, as described in Lupatsch et al. using fish weighing from 500 to 700 g. Chromic oxide (8 g kg 1) was added to the feed as a marker and feces were collected by stripping. Digestible protein (DP)
content amounted to 484F13.2 g kg 1 and digestible energy (DE) to 17.78F0.43 MJ kg 1.