Impact of replacing natural food with commercial feed on the growth and survival of blue bream larvae (Ballerus ballerus) under controlled conditions

Abstract

The effect of replacing natural food with commercial feed on the growth and survival of blue bream, Ballerus ballerus (L.), larvae reared under controlled conditions was investigated. Live food, brine shrimp, Artemia sp. (A), nauplii, was replaced after four (A4P17), eight (A8P13), and 12 (A12P9) days with commercial feed (P). The control groups were larvae fed nauplii (A21) or feed (P21) exclusively for throughout the experiment. The density of larvae was 40 ind. dm^-3, and the rearing temperature was 25 ± 0.5°C. The highest blue bream larval growth rate in the groups fed the commercial feed tested was in group A12P9, in which larvae reached an average body weight of 56.1 mg with an average total length of 21.1 mm. These values were only slightly lower than those obtained in the A21 control sample. Final larval survival in each of the feeding groups ranged from 67% (A4P17) to 93% (A12P9). The larval lowest survival and growth parameters were recorded in control group P21, in which larvae received only commercial feed; this indicated the necessity of using natural food when rearing blue bream larvae.