The fish were fed 1.5% of their biomass d−1 for 12 days (calculated
based on an expected FCR). The daily ration was divided into two
equal portions which were fed at 10:00 and 14:00 h, respectively.
Feed waste was registered and counted throughout the trial. All
feces from the sedimentation columns were collected daily prior to
feeding at 10:00 h, and samples from each three consecutive days
were pooled (i.e., yielding four fecal sampling periods) and stored
at −20 °C until chemical analysis was carried out. Feces from the
first sampling period served as back-up samples, while feces from
the second and third sampling periods were analyzed for protein,