Effects of Chronic Antibiotic Exposure and Water Quality on the External Microbiome and Physical Performance of Killifish (Fundulus heteroclitus)

The external microbiome of a fish has proven to be an important resource for disease prevention and maintaining overall health. However, the common practice of prophylactic antibiotic treatment in aquaculture and the diminished water quality that is associated with urbanized water ways has the propensity to impact this important community and the physical performance of the host fish. Thus, this study tested the impact of chronic antibiotic exposure and water quality on the physical performance of wild caught killifish, Fundulus heteroclitus, in timed swim tests against a set current. Additionally, select animals from the control and experimental groups were exposed to bacterial cultures of Enterococcus faecalis to investigate the susceptibility of the fish to disease. It was found that antibiotic treatment, water quality, and bacterial exposure did not have any statistically significant impact on average fish swim times. Due to the limited sample size and duration of this experiment, future study should look to increase both of these factors elucidate a clear result.