Effects of temperature and stocking density on the growth and survival of juvenile of Litopenaeus schmitti. / Efeito da temperatura e densidade de estocagem no crescimento e sobrevivência de juvenis de Litopenaeus schmitti.

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

01/09/2009

RESUMO

The white shrimp Litopenaeus schmitti is considered a promising species concerning aquaculture; however, there is limited information regarding its growth in captivity. This study aimed to evaluate the effects of temperature and stocking density, as well as the juvenile survival rate of raised L. schmitti in captivity. This study was carried out at the Marine Biology Station of UFRRJ for 42 days. The treatments were distributed in a completely randomized design, in factorial arrangement 2 x 3, referring to water temperature (24 and 26C) and stocking densities (220; 440 and 660 shrimp/m), respectively. After the acclimatization period, weight and individual total length were recorded for every shrimp (n= 240), that were assigned to wire baskets. The average initial weight and total individual length were 0,380,09 g e 34,912,38 mm, respectively. Wire baskets of 0,17 m diameter were considered the experimental units. They were kept on polyethylene tanks which had 150 L of treated seawater and constant aeration. The tanks were cleaned on a daily basis, as data on abiotic factors were collected, such as: salinity, temperature, pH and dissolved oxygen. The temperature was maintained by electrical thermostats heaters. All shrimp were fed on a commercial diet containing 40% protein, on equal quantities, three times a day at 8:00, 14:00 and 20:00 h. At the beginning of the experiment the commercial diet was offered at 40% of shrimp biomass, but this rate was adjusted weekly. Shrimps of every repetition were weighted, in group, once a week. At the end of the experiment, individual weight and total length were measured. The specific growth rate, apparent feed conversion, weight gain (g and %), length gain (%), biomass/ha, survival rate, weight and average total final length were calculated and analyzed to evaluate significative difference related to stocking density and temperature using the ANOVA and Tukey test posthoc. There was no significant difference between the two factors analyzed (p >0,05), except for biomass/ha. The treatments with 26C of temperature and the 220 shrimp/m of stocking density showed a positive effect (p <0,05) on the juvenile L. schmitti growth.

ASSUNTO(S)

camarão branco crescimento ganho de peso recursos pesqueiros e engenharia de pesca white shrimp growth weight gain

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