Effects of Coal Leachates on Fish Spermatogenesis

Coal leachates were examined for toxic effects on fish spermatogenesis. Nonbreeding mummichogs, Fundulus heteroclitus, were induced to enter breeding condition in the laboratory by exposure to 20 °C and a photoperiod of 16L: 8D for 6 wk. During this 6-wk period, mummichogs were dosed in static exposure tanks with water extracts of coal (leachates). Chi-square analysis and Z test of proportions revealed a significant reduction in sperm production by fish exposed to some, but not all, coal leachates. This reduction was as much as 40-fold and occurred in a dose-dependent manner. Ordinarily, nonbreeding mummichogs collected immediately after the breeding season will not enter breeding condition in response to 16L: 8D and 20 °C. Exposure of these photo-insensitive mummichogs to coal leachates under long photoperiod conditions for 8 wk resulted in a significant increase in sperm production. Analysis of weekly sperm production by mummichogs from six field populations, either adjacent to or 2 miles upstream from ...