Weaning of Colossoma macropomum larvae of different ages using different feeding strategies

ABSTRACT: The present study evaluated the weaning of Colossoma macropomum. 6,720 larvae were distributed in 28 tanks (28 L) in a recirculating aquaculture system. Artemia nauplii were offered to the larvae in increasing quantities. The abrupt weaning treatments then began by directly providing extruded commercial feed on the 6th (W6), 11th (W11) and 16th (W16) day of larviculture. The co-feeding treatments (W6co, W11co and W16co) involved a period of co-feeding, whereby the amount of Artemia nauplii was reduced by 20% each day while simultaneously offering a commercial diet. Treatment W6 and W6co had lower weight after the 15th day (21.25 ± 5.35 mg and 25.96 ± 8.52 mg, respectively) and 20th day (34.94 ± 21.24 mg and 41.87 ± 22.61 mg, respectively) day of larviculture. W16 and W16co had greater weight after the 25th day (216.12 ± 43.19 mg and 220.40 ± 14.92 mg, respectively) and 30th day (380.67 ± 88.35mg and 366.96 ± 88.87 mg, respectively). W16 and W16co had greater length at the end of 30 days of larviculture in relation to weaning at younger ages, with a final average of 28.215 ± 1.580 mm and 28.179 ±1.260 mm, respectively. All treatments experienced a reduction in SGR between the 6th and 10th day of larviculture, Treatments W6co, W16 and W16co had higher values (18.80 ± 9.25% day-1, 18.48 ± 3.69% day-1 and 21.21 ± 2.29% day-1, respectively) and W11 the lowest values between the 21st and 25th day (4.17 ± 3.51% day-1). Survival after 30 days was lowest for W6 (64.02 ± 4.49%) and highest for W11co, W16 and W16co (80.89 ± 2.07%, 81.07 ± 2.42% and 85.63 ± 8.30%, respectively). We concluded that, for C. macropomum larviculture, treatments W16 and W16co are better weaning strategies for growth performance and survival.