Effect of dissolved carbon dioxide on oxygen consumption in the Pacific white shrimp, Litopenaeus vannamei (Boone 1931)

A failure in the aeration system of Litopenaeus vannamei rearing with biofloc technology can decrease the oxygen concentrations rapidly and also increase the carbon dioxide (CO2) concentrations at the same rate. We report here an evaluation of the effect of CO2 on the oxygen consumption of L. vannamei. We used a continuous-flow respirometer with water recirculation equipped with a digital fiber-optic oximeter. Eight juveniles of L. vannamei (12.1 +/- 1. 4 g) were used in each treatment with one per respiratory chamber (0.6 L). The shrimp were exposed to six concentrations of CO2 (5, 30, 60, 95, 150, and 300 mgCO(2)/L) with an acute exposure time of six hours. Upon treatment with 5-30 mgCO(2)/L, we observed a consumption of oxygen of 0.233 +/- 0.129 and 0.33 +/- 0.072 mgO(2)/g/h, respectively. Upon treatment with 60 mgCO(2)/L, an increase was observed in the oxygen consumption (0.521 +/- 0.098 mgO(2)/g/h). Upon treatment with 95, 150, and 300 mgCO(2)/L however, the shrimp decreased their oxygen consumption and lost their equilibrium. The CO2 should therefore be maintained at a maximum of 5 mgCO(2)/L during shrimp rearing.