An evaluation of germline mutations and reproductive impacts in fathead minnow (Pimephales promelas) exposed to contaminated sediment

Polycyclic aromatic hydrocarbons (PAHs) have become ubiquitous in the aquatic environment. Some PAHs are mutagenic, potentially causing germline mutations in fish that inhabit PAH contaminated waters. We evaluated the effect of exposure to sediment-borne PAHs on reproduction and germline mutation rates in fathead minnows (Pimephales promelas). Exposure to the contaminated sediment had no significant impact on the reproductive endpoints measured in this study. Germline mutations rates at three microsatellite DNA loci were 1.69 × 10^-3 in fish exposed to PAH-contaminated sediment and 0.55 × 10^-3 in control fish, with zero mutations being observed in fish exposed to sediment from a reference site. While the difference in mutation rates between treatments was not statistically significant for the sample size used (15-19 families per treatment), the observed mutations rates enabled us to estimate the sample size required to detect a significant effect. To our knowledge, this is the first report of germline mutation rates in fathead minnow exposed to an environmental contaminant, providing baseline data for use in the design of future experiments.