Use of Metabolism and Swimming Activity to Evaluate the Sublethal Toxicity of Surfactant (LAS-C12) on Mugil platanus

This study aimed to investigate the toxicological effects of the LAS-C12 on Mugil platanus (mullet). Fishes exposed to 1.0 mg.L for 24, 48, 72, 96 and 120 hours presented significant increase in specific routine metabolism. At the concentration of 0.5 mgL, the active metabolism presented a decreasing trend from 48 h of exposure on. However, only the consumption averages for 72 h were statistically different from the ones obtained for other periods of exposure. The lowest oxygen consumption in this concentration was observed for 24, 48 and 72 hours of exposure. Significant differences between the control and the concentration of 2.5 mgL were observed for the different periods of exposure. It was not possible to measure the consumption of oxygen for 96 and 120 h, because the fishes got tired in less than one minute after they were placed in the respirometer. The time of swimming until exhausted for fish exposed to 2.5 mgL of LAS-C12 for 24 h was 8 minutes. Following 72 hours of exposure to this concentration, the fish got exhausted after 3 minutes.