Abstract
High concentrations of TBT (2.5 to 52.5 times those in muscle) were detected in the blood of three cultured fish species (Japanese flounder, red sea bream, and yellowtail), and in a wild flatfish. The results of gel filtration, performed on serum from the Japanese flounder, showed that TBT was bound to a protein (mol. wt. ca. 50,000). In controlled experiments, Japanese medaka (Oryzias latipes) were fed daily diets containing TBT, polychlorinated biphenyls (PCB), or a combination of TBT+PCB. All contaminant doses were 1 mg/kg body weight per day for three weeks. In the combined TBT+PCB treatment there were significant reductions in spawning frequency relative to toxin-free controls. There also were decreased numbers of both total and fertilized eggs. Exposure to TBT alone significantly reduced the survival of larval fish, which hatched from eggs that contained up to 170 ng TBT/g.
