Illustrated field guide for assessing external and internal anomalies in fish

Abstract : Procedures are described for processing fish for examination of external and internal anomalies and pathologies indicative of exposure to environmental contaminants and other perturbations. For the procedures described here, fish are captured (preferably by electrofishing) and held alive until processing (generally <1 h). Fish are weighed, measured, and necropsied, and a scale sample is obtained from for age determination. Information is given for the collection and preservation of tissue samples for histopathological analysis.