Sex-specific compensatory growth in food-deprived Nile tilapia
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Data
2003-04-01
Autores
Barreto, R.E. [UNESP]
Moreira, P.S.A. [UNESP]
Carvalho, R.F. [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Associação Brasileira de Divulgação Científica (ABRADIC)
Resumo
Female Nile tilapia incubate fertilized eggs in their mouth until they are released as alevins. Consequently, the female may not eat during this period. Thus, it would be expected that female Nile tilapia are more adapted to recovering from fasting than males, which do not display this behavior. To test this hypothesis we conducted an experiment with two groups of fish consisting of 7 males and 7 females each, with one fish per aquarium. The experiment was divided into three phases involving adjustment of the animals to experimental aquaria (0-15th day), fasting (16th-27th day), and refeeding (27th-42nd day). Compensatory growth performance was assessed by specific growth rate, weight, food conversion efficiency and food intake. Food conversion efficiency increased after fasting with a similar rate for both sexes. However, specific growth rate, food intake and weight gain (%) were significantly higher in males than in females in the refeeding phase. Thus, we conclude that male Nile tilapia can compensate for a fasting period more efficiently than females, refuting our hypothesis. A possible mechanism involved in the greater male compensation is that they presented greater hyperphagia than females, concomitantly with a similar rate of food conversion efficiency for both sexes during refeeding, which would probably be provoking greater growth in males.
Descrição
Palavras-chave
Compensatory growth, Fasting, Sex-related growth, Mouthbrooding fish, Nile tilapia, Oreochromis niloticus
Como citar
Brazilian Journal of Medical and Biological Research. Associação Brasileira de Divulgação Científica, v. 36, n. 4, p. 477-483, 2003.