Duration of co-feeding on the Nishikigoi Cyprinus carpio larvae during weaning from live to inert food in an indoor system

ABSTRACT: This study aimed to evaluate the effects of the co-feeding period (C) on the survival and growth of larvae of nishikigoi Cyprinus carpio, during the weaning period from live to inert food. A total of 1680 larvae with initial weight of 1.33 ± 0.12mg and initial length of 6.0 ± 0.33mm were used. The inert diet used was a commercial ration with 55% crude protein and the live food was the newly hatched nauplii of Artemia franciscana. The experiment was conducted following a completely randomized design with six treatments and four replications. Treatments constituted of: a) LF = supply of live food throughout the experimental period; b) C4 = 6 days of live food + 4 days of co-feeding (inert diet and live food) + 16 days of inert diet; c) C8 = 6 days of live food + 8 days of co-feeding + 12 days of inert diet; d) C12 = 6 days of live food + 12 days of co-feeding + 8 days of inert diet; e) IF = supply with inert diet throughout the experimental period; and f) F = fasting. Our results showed that the co-feeding period influences the survival and growth of the larvae. Survival in the treatment with the longest co-feeding period showed an improvement of over 70% when compared to the shortest period. Further, we noted a doubling of the juvenile weight after 26 days of age. There was a quadratic effect for all parameters, with maximum points ranging between 19.4 and 22.6 days of supply of live food. We concluded that the supply of commercial feed as exclusive food is unworkable in nishikigoi larviculture.