Combined effect of temperature and salinity on oxygen consumption on white shrimp Litopenaeus vannamei postlarvae

Abstract

The aim was to evaluate the combined effect of temperature and salinity on consumption oxygen of post-larvae (PL12) white shrimp Litopenaeus vannamei. There were realized five experiments in combination of temperature (15, 20, 25, 30 and 35°C) and salinity (5, 15, 25, 35 and 45 psu). There were used for each experiment 125 bottles DBO of 300 mL, of which, 100 corresponded to the treatments (temperature x salinity) with 20 post-larvae, 20 to the whites (without post-larvae) and 5 were considered to be initial. The bottles were kept in water recirculating with temperature controlled inside of five reservoir of glass fiber. There were realized four readings of the consumption of oxygen for a time of 1, 2, 4 and 8 h. In the first hour, there were obtained 35 readings of the consumption (25 treatments [with post-larvae], 5 whites and 5 initials). At 2 h, the readings corresponded to 30 bottles (25 with post-larvae and 5 whites), and equally at after 4 and 8 h. The high oxygen consumption were obtained to a highest salinity and temperature, though the maximum were 14.36 (35°C, 25 psu) and 13.52 (30°C, 45 psu) µg L^-1 h^-1 PL, and the minim, 0.07 (20°C, 5 psu) µg L^-1 h^-1 PL. The oxygen consumption were significantly (P<0.05) affected by temperature, salinity and interaction of both factors. Whereas at 25 and 30°C and 15 and 25 psu, there were obtained the best oxygen consumptions.