Ecology, genetic population structure, and molecular phylogeny of fishes on coral reefs in the Gulf of Aqaba and northern Red Sea

Abstract

Aim of this thesis is the study of biogeography and ecology, genetic population structure, and molecular phylogeny of fishes on coral reefs in the Gulf of Aqaba and northern Red Sea. Ecological and genetic pattern are compared on different spatial scales and molecular markers add a temporal scale to study of evolutionary processes.Biogeographic analysis supported the differentiation of the Arabian sub-province from the Indian Ocean, but the affiliation of the Arabian Gulf is not clear.The analysis of the genetic population structure based on the mtDNA control region revealed homogenity between populations of Pterois miles in the Gulf of Aqaba and northern Red Sea and indicate high levels of gene flow.Investigations on interrupted gene flow in the evolutionary history of lionfishes (Scorpaenidae) revealed a differentiation between the Indian Ocean and Western Pacific. Phylogenetic analysis of cyt b and 16S rDNA sequences of the siblings P. miles and P. volitans suggest a divergence time of 2.4-8.3 million years. This coincide with tectonic events and sea level changes in Southeast Asia during the glacial maxima. Additionally, this genetic study gave indications for taxonomic revision of the genera Pterois and Dendrochirus.Ecological studies on the shore fishes off the Jordanian coast showed that fish species richness was positively correlated with hard substrate cover and benthic diversity. Abundance of corallivores was positively linked to live coral cover. The multivariate analysis of the fish community has revealed several associations of fishes in different habitats, such as deep and shallow reef slope.The northern tip of the Gulf of Aqaba and its western shores are particularly subject to human disturbances. Fish abundance at an industrial site was 50% lower than on an undisturbed reef and the trophic community structure was different.