Research Product

Eggs and larvae of decapod crustaceans and embryos of Mulinia lateralis were exposed to chlorinated seawater for varying periods in continuous flow systems. Mortality, developmental rate, and general behavior were recorded. Panopeus herbstii zoeae were more sensitive to chlorine-induced oxidants (CIO) than eggs or adults (96-hr LC50 ca. 2.8 ueq/l identical with 0.1 mg/l). The 96-hr LC50 for Pagurus longicarpus zoeae was approximately the same as for Panopeus zoeae. The 120-hr LC50 for Pagurus zoeae was 1.4 ueq/l (0.05 mg/l). Development was slightly delayed for Pagurus zoeae at CIO levels as low as 0.6 ueq/l (0.02 mg/l). Mulinia embryos exposed for 48-hr had an LC50 between 0.3 and 3.0 ueq/l (0.01 and 0.1 mg/l). Mulinia embryos exposed to chlorinated seawater for 2 hr had an LC50 of about 2.0 ueq/l (0.072 mg/l); subsequent survival rates for larvae in unchlorinated seawater were unaffected by prior exposure to CIO. The effects of CIO on serum constituents in Callinectes sapidus occurred sporadically and appeared unrelated to dose or mortality. Similar effects were noted for oxygen consumption in whole crabs and excised gills. It was concluded that there are no physiologically significant sublethal effects on CIO on serum constituents (osmoregulation) or oxygen consumption of whole blue crabs or excised gills. Blue crab antennules are sensitive to sublethal doses of CIO. Spawning and feeding are inhibited by sublethal doses of CIO. This effect disappears when CIO is removed.