Feeding preference in juveniles of Acipenser naccarii Bonaparte 1836

The objective of these experiments was to determine juvenile sturgeon ( Acipenser naccarii) ability to capture live prey as well as to determine their feeding preferences when born and raised in captivity and fed on manufactured feeds until the commencement of the experiment. The purpose was to improve their nutrition and to aid in the development of restocking programmes. For the experiment, one non-adapted group ( A) and one group (C, control) previously adapted for 10 days to live feed were used; each group comprised eight similar-age sturgeon (16 fish in total). The experiment was repeated four times for each specimen in group A ( A1 to A4) and twice for each in group C (C1 and C2). Using aquaria of 40-L capacity in each experiment, each fish, in isolation, was provided with three individuals of each of the 12 prey categories tested. The number of attacks, differentiating between successful and unsuccessful, were counted, and the elapsed times until the first and third successes were measured together with the type of prey taken. During the course of the experiment, there was a significant reduction in the number of times required to achieve both the first and third successes, as well as a significant increase in the number of successes with time. Preferred prey were those of the worm type (Tubificidae and Lumbricidae).