IMPACT OF ANOXIA AND SULFIDE ON THE VIABILITY OF EGGS OF 3 PLANKTONICCOPEPODS

Eggs of 3 calanoid copepods Acartia tonsa, Centropages hamatus and Lab idocera aestiva were exposed to either anoxia or anoxia/sulfide. Mean sulfide concentrations ranged from 283 to 352 M. Viability, determined at 4 d intervals for 32 d and judged as hatching success under normox ia was variable, but generally declined with increasing time of exposu re. Values for hatching success were transformed to probits to determi ne the median lethal times of exposure to anoxia and anoxia/sulfide an d 95% confidence limits. We observed no significant difference in the mortality of eggs exposed to anoxia/sulfide compared to anoxia alone a nd suggest that eggs switch to anaerobic metabolism when exposed to an oxia.