Time to death of mosquitofish (Gambusia holbrooki) during acute inorganic mercury exposure: population structure effects.

Times-to-death (TTD) of mother and offspring mosquitofish (Gambusia holbrooki) were examined during acute exposure to mercury concentrations of approximately 1.0 mg/L. Median TTD were more similar for fish sharing a common mother (defined herein as a sibship) and microhabitat during maturation than between sibships. Field populations may exhibit structure similar to that of these sibships. Correlations between broods (or other population subunits) and allozyme genotype could be responsible for transient, genotype effects noted during electrophoretic surveys attempting to measure population level response to toxicants.