Abstract

The objective of this study was to investigate the possible effects of caffeine on the performance of juveniles of Nile tilapia. One hundred and forty four (144) juveniles of Nile Tilapia with mass, total length and initial mean height of 2.94 ± 0.16 g, 5.19 ± 0.14 cm and 1.49 ± 0.04 cm, respectively, were used. The fishes were housed in 24 plastic boxes in a closed water recirculation system, where each box contained six fishes. A completely randomized design with six treatments and four replicates was used. The treatments tested were 0.0; 0.5; 1.0; 1.5; 2.0 and 2.5 g of caffeine/3 kg of feed. The experiment lasted for 40 days. Caffeine levels, up to and including 1 g/3 kg of diet, positively affected weight, total length, standard length, height, weight gain, feed intake and specific growth rate. Dosages higher than 1 g/3 kg resulted in negative results. Caffeine can be added in up to 1 g/3 kg of feed without negatively affecting the productive performance of juvenile Nile Tilapia fingerlings.

Key words: Production index, metabolism, fish, trimethylxanthine.