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The legacy of dispersal: larval experience shapes persistence later in the life of a reef fish

Authors


Correspondence author. Email: jeffrey.shima@vuw.ac.nz

Summary

1. Movement pathways of individuals can be shaped by heterogeneity in the dispersal environment that separates origin and destination patches. However, effects of the dispersal environment on the phenotype (or future fitness) of dispersers is poorly known; individual experiences during dispersal may have latent effects on the performance or persistence of later life-stages.

2. We evaluated such ‘legacy effects’ for dispersing reef fish larvae using (i) otolith (ear stone) microchemistry to characterize two distinct dispersal pathways and (ii) otolith microstructure to estimate ‘larval quality’ (a composite of five measured larval phenotypes). We conducted a reciprocal transplant field experiment to evaluate selective mortality after dispersal as a function of larval quality. We conducted longitudinal sampling of natural cohorts of reef fish through to adulthood to quantify shifts in the distribution of larval quality in local populations.

3. We found the quality of dispersers to be variable and determined by their experience in the larval dispersal environment. Larval quality of successful dispersers predicted their subsequent survival after dispersal in reciprocal transplant experiments. Longitudinal sampling was consistent with short-term field experiments, and revealed that survivors to adulthood were disproportionately comprised of high quality larval dispersers.

4. Overall, our results suggest that conditions in the dispersal environment shape future fitness of individuals after successful dispersal, and that this can indirectly mediate dispersal patterns and connectivity in a metapopulation.

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