Energetic and behavioral responses by the common goby, Pomatoschistus microps (Kroyer), exposed to linear alkylbenzene sulfonate

The acute toxicity of linear alkylbenzene sulfonate (LAS) on the common goby (Pomatoschistus microps), an estuarine fish, was established during a 96-h static exposure. The median lethal concentration was 2.6 +/- 0.49 mg LAS/L (mean +/- 95% confidence limit). The acute behavioral responses to LAS at different concentrations were excess mucus secretion and apathy at 1.0 mg/L; air gulping, distension of the mouth and opercula, change in pigmentation, and erratic swimming at 2.0 to 3.0 mg/L; and loss of balance and reactivity at greater than or equal to 4.0 mg/L. The frequency of operculum opening increased with increasing LAS concentrations and appeared at 4.0 mg/L, with a significant doubling in relation to the frequency observed in control fish (p = 0.025). The physiological responses by P. microps after prolonged exposure to sublethal and environmentally realistic concentrations of LAS (0.05-1.0 mg/L) were observed under semistatic conditions in the laboratory. Ingestion, respiration, and growth were also measured during 28 d of exposure. A significant decrease in growth and respiration was found at 0.1 mg LAS/L (p = 0.049 and 0.033, respectively), but ingestion was not affected. The effect concentrations for growth and respiration represent the lowest-observed-effect concentrations, which are both lower than values previously reported for fish. Gross conversion efficiency was affected negatively at 1.0 mg LAS/L (p = 0.001). Pomaroschistus microps is recommended as a suitable and relevant test organism for ecotoxicological experiments.