ABSTRACT
Rates of predation were determined during the embryonic and larval lives of Dendraster excentricus, Strongylocentrotus franciscanus and S. purpuratus in a series of laboratory feeding experiments. Eggs and early embryonic stages of all three species were most susceptible to predation by brachyuran crab zoea (Hemigrapsus nudus). Swimming blastulae, gastrulae and prism larvae were generally captured at intermediate rates while echinoplutei were captured at relatively low rates. Mean zoea clearance rates decreased from 0.67 to 0.30 liters/zoea/day during the transition of prism larvae into plutei. Reduced susceptibility to predation by H. nudus is related to increasing larval size and to the ontogeny of larval swimming behavior.
