Meeting Abstract

S3-2.1  Wednesday, Jan. 4  Two reproductive strategies and their implications for population dynamics: An individual-based model of the poecilogonous spionid Boccardia proboscidea OYARZUN, FX*; GR├╝NBAUM, D; University of Washington, Seattle; University of Washington, Seattle

Poecilogony is the ability of some marine invertebrate species to alternate between multiple developmental modes. The spionid polychaete Boccardia proboscidea has three different reproductive modes, including one in which all eggs inside capsules develop as planktotrophic larvae and another in which capsules have approximately 90% nurse eggs and a mixture of planktotrophic and adelphophagic larvae. In this study, we used an individual-based model to explore the implications of these two strategies for population dynamics under different environmental conditions and at different reproductive rates. The model was very sensitive to planktotrophic larval mortality in the pelagic phase, and to catastrophic events in the benthic environment. In addition, reproductive females using the mixed-strategy reproductive mode performed better than individuals that produced only planktotrophic larvae, under low disturbance and reproductive rates. The model was useful in identifying gaps in knowledge, such as mortality rates in the plankton, and in elucidating the implications of current knowledge about this species.