Effects of cadmium on hemolymph composition in the shore crab Carcinus maenas

Abstract

Effects of cadmium exposure on regulation of osmolality and sodium, chloride, potassium, calcium, magnesium, and cadmium levels in the hemolymph of the shore crab C. maenas (L.) were studied. Exposure to 1 mg Cd l super(-1) at 15.5 degree C and 400 mOsm ( similar to 14 ppt) had no effects on ionic concentrations during 48 d. Exposure to greater than or approximate to 4 mg Cd l super(-1) augmented calcium levels in the hemolymph, while magnesium concentrations were reduced after prolonged exposure to 2 and 4 mg Cd l super(-1). In some experiments exposure to 10 mg Cd l super(-1) augmented Na super(+), K super(+), and Cl super(-) concentrations and osmolality, but the effects were not consistent. Crabs exposed to less than or approximate to 2 mg Cd l super(-1) maintained cadmium levels in the hemolymph at or slightly below ambient cadmium concentrations, while cadmium levels in the hemolymph rose above ambient levels in crabs exposed to 4 to 10 mg Cd l super(-1).