Weaning of the wedge sole Dicologoglossa cuneata (Moreau): influence of initial size on survival and growth

Abstract

The weaning phase can be decisive in fish-culture viability. In this work, the relationship between the initial size and weaning success has been studied in wedge sole (Dicologoglossa cuneata). For each age (30, 50, and 70 days after hatching, DAH), two to three sizes were selected, and all were put on the same feeding schedule for 20 days. Each batch (three replicates) was sampled at 1, 10, and 20 days. Specific growth rate (SGR) and survival were compared at the end of the co-feeding period, after 10 days on dry feed only. The best results for survival and growth were found with the smallest larvae, and vice versa. The SGRs and survival rates recorded during the co-feeding period were higher (0.8-15.6 day -1 and 68.3-97.8%) than those from the dry-food phase (0.9-4.7 day -1 and 56.3-66.7%). Successful weaning (survival = 65% and SGR = 9.3 day -1 ) is possible with 30 DAH larvae (7.6-8.1 mm and 3.9-4.6 mg). In conclusion, the most effective weaning would be possible at 30 DAH, implying significant Artemia savings (25-50%).