Taste preferences of tiger puffer ( Takifugu rubripes ) to common amino acids and feed attractants

The taste preferences of fish which directly influence the feeding action are diversified among species. The present study evaluated the taste preference of tiger puffer (Takifugu rubripes) to a number of compounds including an achiral amino acid (glycine), 16 L-amino acids, 15 D-amino acids and seven commonly used feed attractants. A total of 18 intact and healthy tiger puffers (initial body weight 43.33 ± 3.91 g) were randomly separated in nine 100-L tanks (two fish in each tank as one statistical unit). The test compounds were added in aqueous agar solution to make test pellets. Five parameters indicating the response of fish to pellets, namely, pellet grasp number (GN), ingestion ratio (IR, %), touch span (TS), rejection number (RN) and palatability index (PI), were used for the evaluation of feed palatability, based on which the test compounds were finally identified as attractive, indifferent or repulsive. The Spearman correlation analysis revealed that there was a significant correlation among GN, IR, RN and TS (p < 0.05). The L/D-alanine, L/D-proline, L-serine, L-histidine, glycine and inosine-5'-monophosphate disodium salt octahydrate, whose IR (over 90%) is significantly higher than that of the control, were identified as attractive (p < 0.05). This investigation provided basic information about the taste preferences of tiger puffer to potential feed attractants.