Macroecology and Microevolution of reef fishes in the Arabian Peninsula

Felipe de Oliveira Torquato

Abstract

The biogeographic patterns of reef fishes observed nowadays are the result of a long and complex history that likely involve a number of vicariance events. This thesis seeks to understand the proximate causes of the spatial pattern of genetic and taxonomic diversity of reefs fishes in the Arabian Peninsula. To do so, we took advantagens of recent genetic approaches to determine whether genetic metapopulation structure exists within Yellowbar angelfish Pomacanthus maculosus, a coral-dependent species that inhabits a broad geographical range within the Western Indian Ocean. And if so, determine which form it takes. The present results most corroborate with previuous studies and suggest the presence of two barriers for marine dispersal, identified in the south of Arabia and along the eastern Somali coast, that structure the population of P. maculosus into three genetic clusters across the sampled area. However, the potential causes of this genetic discontinuities are still unclear, with hypotheses relying on both parapatric speciation outcomes from repeated vicariance events, such as the lowering sea level during the last glaciation, and ecological speciation due to the large spatial gradients and temporal fluctuations in physical conditions. Little attention has been given to test hypotheses on the role played by other ongoing processes, such as the ocean circulation and biological traits, in the maintenance of both the biogeographical breaks and genetic population structures. In order to better understand these processes and the strength of dispersal barriers, we used a high-resolution hydrodinamic model to design a biophysical model. We simulatied multitaxon larval dispersal through previous described biogeographic barriers in the seas around the Arabian Peninsula, and demonstrated how biological traits, such as the reproductive strategy and ontogenetic vertical migration, determine the success of particles (fish larvae) being transported through these barriers. Our results provide detailed predictions that can be compared to previous and future empirical studies investigating the biogeograaphic and genetic patterns in the seas around the Arabian Peninsula. In addtion, this thesis explores the taxonomic and functional diversity, vertical zonation and diel migrations of fish aggregations at the oil platforms in Al Shaheen oil field in the central Gulf (north-eastern Qatar EEZ). It represents the first assessment of fish communities inhabiting oil and gas platforms in the Arabian/ Persian Gulf. Besides new records of fish species for Qatar, we showed a large diversity of fish fauna around the platforms of the Al Shaheen oil field with evident vertical variability in the functional and taxonomic composition.
Original languageEnglish
PublisherNatural History Museum of Denmark, Faculty of Science, University of Copenhagen
Publication statusPublished - 2018

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