Meeting Abstract
Sodium perchlorate (NaClO4) is a strong oxidizing agent with a variety of military and industrial uses. Its widespread use and water solubility have made perchlorate a common contaminant of surface and ground waters across the United States. Perchlorate is an endocrine disruptor that inhibits thyroid hormone production. Here, we investigate the effects of sodium perchlorate on behavioral patterns in zebrafish (Danio rerio). Because behavior is tightly linked to brain development, a change in behavior of fish exposed to perchlorate could have important neurological implications for both humans and wildlife. We reared groups of 24 fish in three perchlorate concentrations (10ppm, 30ppm and 100ppm) and a control treatment (0ppm). At 5 and 10 days post-fertilization (dpf), we quantified their movements under three lighting conditions (lights on, lights off, and strobing) using a NOLDUS system. After conducting a principal components analysis, two major relationships were observed: at 5dpf, fish exposed to perchlorate moved significantly more under the lights on condition than did control fish. At 10dpf, fish in the control group moved more than did fish in any of the perchlorate-exposed groups under the lights off and strobing conditions. In both cases, the fish exposed to perchlorate showed a significant alteration in behavior as compared to the control group. The results from the 5dpf trial are especially notable because zebrafish normally show more activity in dark environments, and the observed behavior would likely make them more susceptible to predation under natural conditions. Further studies are necessary to determine the underlying mechanisms responsible for altered zebrafish behavior, and to examine the generalizability to other animals and people.
