Crescimento e produtividade de juvenis de robalo-peva a diferentes temperaturas e taxas de alimentação

Abstract

Resumo -O objetivo deste trabalho foi avaliar o efeito da temperatura e da taxa de alimentação sobre o crescimento e a produtividade de juvenis de robalo-peva (Centropomus parallelus). Utilizou-se experimento fatorial com duas temperaturas (25 e 28 o C) e duas taxas de alimentação (3 e 6% da biomassa ao dia), com três repetições para cada combinação de temperatura e taxa. Os peixes (9,80±0,41 g; 9,86±0,14 cm) foram alimentados duas vezes ao dia durante 60 dias. A cada 15 dias, foram realizadas amostragens para corrigir a quantidade de ração oferecida. Não houve mortalidade durante o experimento. Maior crescimento em peso e comprimento foi obtido nos animais submetidos à temperatura de 28ºC. Ganho de peso, biomassa final, conversão alimentar aparente e taxa de crescimento específico foram influenciados pela taxa de alimentação e pela temperatura. A oferta de 3% da biomassa ao dia a 28ºC proporciona melhores índices de crescimento e produtividade para juvenis de robalo-peva.Termos para indexação: Centropomus parallelus, aquicultura, bem-estar animal, desempenho produtivo, qualidade da água. Growth and yield of juvenile fat snook at different temperatures and feeding ratesAbstract -The objective of this work was to evaluate the effects of temperature and feeding rates on growth and productivity of juvenile fat snook (Centropomus parallelus). A factorial experiment with two temperatures (25 and 28°C) and two feeding rates (3 and 6% of biomass per day) was used, with three replicates for each combination of temperature and rate. Fish (9.80±0.41 g; 9.86±0.14 cm) were fed twice a day during 60 days. Every 15 days, samples were taken to correct the amount of food offered. No mortality was observed during the experiment. A greater growth in weight and length was obtained in animals subjected to the temperature of 28°C. Weight gain, final biomass, apparent food conversion, and specific growth rate were influenced by feeding rate and temperature. The offer of 3% of biomass per day at 28°C provides better growth and productivity indices for juvenile fat snook.

Does intensive feeding frequency affect growth performance of common snook Centropomus undecimalis (Bloch, 1792)?

“…Water quality parameters showed that the system used for recirculation was effective in maintaining the quality of water suitable for the maintenance of the species. The values were all within the variation range considered suitable for snook culture (Ferraz and Cerqueira, 2010;Oliveira et al, 2013). Thus, our results demonstrate the feasibility of common snook juveniles growing in salt water recirculation systems.…”

Performance of cobia grown in brackish water and fed with different feeding rates

“…The obtained results fit a linear function, with higher values as the feeding rate increased: 1.38±0.36 g for 1% LW per day, 1.89±0.31 g for 3% LW per day, 2.01±0.19 g for 5% LW per day, and 2.08±0.29 g for 7% LW per day. Other authors also observed that the daily weight gain of the fish was directly proportional to the rate of feed used (Nhu et al, 2011;Al Zahrani et al, 2013;Oliveira et al, 2013). In Brazil, cobias fed with a feeding rate of 3%, at different feeding frequencies, presented a daily weight gain of 1.48 to 1.67 g (Costa-Bomfim et al, 2014).…”

“…When evaluating the different feeding rates for fat snook, Oliveira et al (2013) found that weight gain, final biomass, apparent food conversion, and SGR were influenced by different feeding rates of 3 and 6% LW per day. According to the authors, the weight gain and the final total weight of the fish that received daily feeding rates of 3% were significantly higher than those receiving 6%, as observed in the present study.…”

“…However, when evaluating 2.0-g samples of the camouflage grouper, Epinephelus polyphekadion, in Asia, Al Zahrani et al (2013) found that the rate of 1.2% provided the best results. For specimens of fat snook (Centropomus paralellus), with a mean weight of 9.8 g, a 3% rate provided a better productive performance (Oliveira et al, 2013). The obtained results are indicative that the used feeding rates of 2 to 6% may be inadequate to reach the zootechnical potential of cobia raised in nurseries with low salinity waters.…”

<b>Performance of fat snook juveniles reared at different temperatures

“…Similarly to the results found in this study, by analyzing the effects of stocking densities (1, 2, 4 and 8 fish L -1 ) of fat snook juveniles in opened salt water circulation systems, Corrêa and Cerqueira (2009) has also found low levels of total ammonia (0.006 ± 0.001), at 25.1 ± 0.90°C, salinity of 35 g L -1 and pH of 7.7 ± 0.2. However, in a study performed by Oliveira et al (2013) with juvenile of the same species in a static system with 80% of water renewal twice a week, when evaluating different feed rates (3 and 6% per day) and temperatures (25 and 28°C), it was observed that at 25°C and 6% of the fish's biomass per day, total ammonia reached 1.29 mg L -1 . The authors reported that this was probably due to a lower growth performance of fish in comparison to the other tested treatments.…”