Physical-biological interactions underlying the phylogeographic patterns of coral-dependent fishes around the Arabian Peninsula

Abstract

ABSTRACTAimTo test the hypothesis that phylogeographic pattern of coral-dependent fish species inhabiting the Arabian Peninsula may be driven by a combination of ocean circulation, larval behavior and seascape features.LocationThe present study focuses on three such putative oceanographic barriers around the Arabian Peninsula: the Bab el-Mandeb Strait, the Strait of Hormuz and the upwelling off Oman.TaxMultitaxa.MethodsA biophysical modeling system that relies on stochastic Lagrangian framework and Individual-Based Model was used to simulate larval dispersal through the three putative barriers, by tracking three-dimensional movements of virtual particles in ocean circulation scenarios. We explored the range of dispersal capabilities across reef fish species by creating 72 hypothetical strategies, each representing a unique combination of five biological traits: pelagic larval duration, spawning periodicity, mortality rate, reproductive output and vertical migration.ResultOur results showed that the strength of the barriers was highly variable as a function of all biological traits (except reproductive output) and indicated high asymmetry of connectivity, and hence gene flow, between adjacent areas. In addition, direction and distance travelled by the virtual larvae varied according to both the geographic position of releasing site and biannual monsoonal winds. On average, larvae released during the summer exhibited a higher potential for dispersal than larvae released in wintertime.Main conclusionsOur biophysical models complement the few existing empirical research on population genetics, and the predictions presented here serve as testable hypotheses for future phylogeographic studies around the Arabian Peninsula.