THE CONSEQUENCES OF BROADCASTING, BROODING, AND ASEXUAL REPRODUCTION IN ECHINODERM METAPOPULATIONS

Different modes of reproduction were examined in the context of entire life cycles for seven starfish species so that adult survival could b e compared with reproductive output and first year survival. Data were assembled from the literature and included two asexual species, Linck ia multifora and Nepanthia belcheri; two brooders, Asterina phylactica acid Leptasterias hexactis; one species with benthic eggs that does n ot brood, Asterina gibbosa; one species with lecithotrophic developmen t in the plankton, Patiriella pseudoexigua; and one planktotrophic spe cies, Pisaster ochraceus. A negative correlation was found between fir st-year survival and adult survival rates which also correlated with m ode of reproduction: highest adult survival and lowest first-year surv ival was found for P. ochraceus, the planktotrophic species, and lowes t adult survival was coupled with highest first-year survival in asexu al species. A matrix model was developed to explore the metapopulation consequences of different modes of reproduction. Asexual species are similar to species with planktonic larvae that also have long-lived ad ults in that both are well insulated from the vagaries of planktonic l ife, one by avoiding the plankton all together and the other by having very low transition probabilities for the first year of life but high transition probabilities for retention of adults in the population. S pecies with short-lived adults and planktonic development of larvae ar e more closely tied to changes in first-year survival rates with respe ct to over-all dynamics of metapopulations.