The relationship between egg size and fertilization success in broadcast-spawning marine invertebrates

Egg size is a critical life-history trait because it can profoundlyinfluence offspring fitness and the number of offspring thatcan be produced. Recently, interest has grown in how egg sizeinfluences fertilization rate and in turn how sperm availabilitymight influence the evolution of egg size among broadcast-spawningmarine invertebrates. In this article I review the empiricalevidence on the ways in which egg size and egg accessory structuresinfluence fertilization and theoretical models of the ways spermavailability might influence the evolution of egg size. Evidencesuggests that egg size does influence the collision frequencywith sperm, and models suggest that sperm availability can influenceselection on egg size. Sperm availability appears to be oneof the several factors that influence optimal egg size in broadcast-spawningmarine invertebrates.