The larval legacy: cascading effects of recruit phenotype on post-recruitment interactions

For organisms with complex life-cycles, the abundance of individuals in a given stage is driven by the quantity of individuals in the previous stage. The successful recruitment of juveniles to adult populations is, however, the product of both recruit quantity and quality. Previous studies on recruit quality have revealed that better quality individuals have higher growth and survival, yet few studies have considered how recruit quality and quantity interact. In a sessile marine invertebrate, we experimentally tested whether the larval food environment causes variation in recruit quality and affects post-metamorphic performance. We found that larvae that were fed higher concentrations of phytoplankton had higher survivorship, but that this higher survivorship meant recruit density was higher in this treatment, intensified intraspecific competition and lowered post-metamorphic growth. Our results highlight the complex repercussions that the presence of phenotypic links among life-history stages can have for population dynamics and the interdependence of pre-and post-recruitment processes in shaping populations. Overall, we suggest that pre-recruitment events can shape the post-recruitment environment independently of recruit number.