Taste sensitivity of Persian sturgeon (Acipenser persicus) to sweetness and bitterness

In this study, taste preference of juveniles of Persian sturgeon were identified to 4 concentrations of sucrose (10, 1, 0.8 and 0.5) and 4 concentrations of calcium chloride (10, 1, 0.5 and 0.1) by using behavioral assay method. The fish used were divided into 3 weight groups: small group (average weight was 7-10 g), medium group (15-20 g) and large group (23-28 g). The results of index of palatability, for both intra-oral and extra-oral receptions, revealed that the differences among 3 weight groups were not significant generally (p> 0.05). It is also found that calcium chloride had positive effect on extra-oral taste reception in all 3 weight groups. In other words, the index of extra-oral palatability increased by increasing concentration. The maximum levels of index of intra-oral palatability for calcium chloride were observed at concentrations of 1% (for small group) and 10% (for medium and large group). But sucrose had negative effect on number of catching acts, just for large group, and it had also negative effect on consumption of granules for all 3 weight groups. Based on these results, we can say addition of 0.5-1 % calcium chloride in juveniles of Persian sturgeon diet can improve feeding status in this species.