ABSTRACT
Potentially toxic environmental heavy metals may enter animals across the integument [1,2], by way of the gills [3-5], or through the gut in food [6,7]. Elimination of metals from the animal may occur across the same tissues and by way of the kidneys. Trace amounts of certain metals (e.g., zinc, copper, iron) are needed by most animals for a variety of metabolic processes, but high concentrations of all metals can be toxic and must be regulated. Aquatic invertebrates possess a variety of organ and cellular detoxi cation processes that reduce the concentrations of potentially toxic metals circulating in the blood, while maintaining proper concentrations of those metals needed for speci c physiological and biochemical functions. These regulatory mechanisms include (1) physiological
11.1 Introduction .......................................................................................................................... 295 11.2 Gastrointestinal System ........................................................................................................296
