Sexual anomalies in male and female phyllodiaptomus tunguidus shen & tai in a Chinese reservoir (Copepoda, Calanoida)

We describe malformations in the antennules in Phyllodiaptomus tunguidus Shen & Tai, 1964, a freshwater calanoid copepod found in Aha Reservoir, Guiyang, China. The right antennule of one female and both antennules of a male had become geniculate. Emissions of chemical substances, including mercury and various unspecified organic compoounds, are known to occur in the reservoir and may have caused some recent mass mortalities of fish here. It is suggested that the anomalies of the copepods reported herein might also be correlated with the observed environmental pollution