Effects of Endrin on Blood and Tissue Chemistry of a Marine Fish

Abstract

Adult northern puffers, Sphaeroides maculatus, were exposed to graded concentrations of endrin, a chlorinated hydrocarbon insecticide, at 20 C, 24‰ salinity, and pH 8.0. All animals subjected to 10.0 ppb of endrin died within 24 hours. At concentrations of 1.0 ppb of endrin, or lower, no mortality occurred within 96 hours. Blood and tissue samples from fish surviving the 96-hour exposure were analyzed by photoelectric colorimetry and atomic absorption spectroscopy. Mean hemoglobin content and relative liver size of puffers exposed to endrin concentrations of 1.0, 0.5, 0.1, or 0.05 ppb were not significantly different from those of controls. Although we found no meaningful changes in levels of serum chloride, gamma-globulin, and uric acid, we did find that the concentrations of sodium, potassium, calcium, and cholesterol in serum were consistently higher in experimental animals than in controls. Moreover, concentrations of sodium, potassium, calcium, magnesium, and zinc in the livers of test animals were consistently lower than in those of the controls. Concentrations of the same cations in gill tissue fluctuated widely. Exposure to sublethal concentrations of endrin impaired liver function, as evidenced by the transfer of major cations from the hepatic tissue into the serum and by elevated serum cholesterol.