Evolutionary Ecology of Larval Types
This chapter reviews selected aspects of the evolutionary ecology of marine invertebrate larval types and how they relate to available life-history theory for marine invertebrate species. It suggests which of the theories and models may be most useful, which can gainfully be tested, and where any conflicts or contradictions lie. The dispersal potential of larvae has frequently been inferred from their different nutritional modes; feeding larvae have longer development periods than non-feeding larvae and are therefore assumed to have relatively widespread dispersal. The evolution of the feeding larva opened up a wide range of evolutionary opportunities for the early invertebrates. The boundary condition for the evolution of non-feeding larvae in Roughgarden’s model is based on ratios of growth to mortality in larval and adult habitats. Non-feeding larval development is generally associated with far shorter developmental periods. In the process of losing a pelagic larval stage, gene-flow between distant populations is likely to be reduced.