Reduction in reproductive activity from degeneration of testicular follicles in Megapitaria squalida (Mollusca: Bivalvia) exposed to metal pollution in the Gulf of California.

Over a reproductive cycle, the prevalence and intensity of degeneration of testicular follicles in Megapitaria squalida collected from the mining port of Santa Rosalia (a highly metal-polluted area), and San Lucas (a less polluted site), Gulf of California, Mexico, were evaluated. At San Lucas, most individuals had a typical testicular structure, and degeneration of testicular follicles was present in 9.5 % of spawning organisms.