After one week of acclimatization, two fish meal diets — one with 7 mg kg−1 synthetic glycoalkaloids (GFM) and one control (FM), a PPC control without additional attractants (PP), and six PPC diets with blood meal (BM 4 or 8%), mussel meal (MM 4 or 8%) and a free amino acid mixture (AM 0.5 or 1.0% alanine, glycine and betaine) as attractant were fed in triplicate until apparent satiation over a period of 56 d to the experimental groups (7 fish per tank, average initial weight 52.8 ± 0.3 g).