Pelagic dispersal of larvae in sessile marine invertebrates could in principle lead to a homogeneous gene pool over vast distances, yet there is increasing evidence of surprisingly high levels of genetic differentiation on small spatial scale. To evaluate whether larval dispersal is spatially limited and correlated with distance, we conducted a study on the widely distributed, viviparous reef coral Seriatopora hystrix from the Red Sea where we investigated ten populations separated between ∼0.150 km and ∼610 km. We addressed these questions with newly developed, highly variable microsatellite markers. We detected moderate genetic differentiation among populations based on both F ST and R ST (0.089 vs. 0.136, respectively) as well as considerable heterozygote deficits. Mantel tests revealed isolation by distance effects on a small geographic scale (≤ 20 km), indicating limited dispersal of larvae. Our data did not reveal any evidence against strictly sexual reproduction among the studied populations.
Bibliographical noteFunding Information:
Acknowledgements The Egyptian Environmental Affairs Agency and the Israel Nature and Parks Authority kindly gave us permission to sample S. hystrix from the Red Sea. This study was funded by the Minerva Foundation, the Minerva Center for Marine Invertebrates Immunology and Developmental Biology and by a grant from the Deutsche Forschungsgemeinschaft (NU 51/5 to BN and RT). We thank all people who provided field assistance, especially M. Rehberg and L. Bongiorni. We are grateful to X. Turon for running the simulations to evaluate the possible occurrence of clonal reproduction. We also thank J.M. Bohn for his help with the figures and A. Baird for carefully checking our English.
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Aquatic Science