Egg production by Acartia tonsa in Long Island Sound

The egg production of adult Acartia tonsa females in Long IslandSound, NY, during and after the fall bloom, was measured inshort-term (8 h) incubations in natural seawater, and estimatedfrom the egg-ratio method, using preserved samples of eggs andfemales. Egg production, as estimated from the in cubation technique,closely tracked changes in chlorophyll concentration with time.The fecundity estimates from the egg-ratio method were significantlylower than from the incubation method in September but werenot significantly different in October. We suggest that a comparisonof the egg production rates using these two techniques may bea useful way of gaining some insight into the extent of eggpredation in the field. We attribute differences between eggratio and incubation fecundities in September to ctenophorepredation.