Meeting Abstract

P2.55  Jan. 5  All eggs are not created equal: Inter- and intra-population variation in gastropod egg size COLLIN, R; Smithsonian Tropical Research Institute collinr@si.edu

A single egg size is often attributed to each species of marine invertebrate, and little attention is paid to intra-specific variation in egg size. For many species, however, several different egg sizes have been reported in the literature. Presumably, egg size can vary among females or among populations, and such variation must be one of the first steps in the evolution of different modes of development. Here I examine inter-brood, inter-female and inter-population variation in egg size for two sympatric species of marine gastropods, Crepidula atrasolea and Crepidula ustulatulina and show that much of the variation in egg size occurs within a population and even within females. Eggs produced at higher temperatures are also slightly smaller than those produced at low temperatures and there was no difference between populations on the Atlantic and Gulf coasts of Florida.