Comparative population genetics, larval dispersal and evolutionary aspects of Antarctic fishes (Notothenioidei)

• Main Author: Damerau, Malte
• Format: Thesis
• Language: English
• Published: 2013
• Subjects: Antarctic; Southern Ocean; Antarc*
• Online Access: https://oceanrep.geomar.de/id/eprint/22955/; https://oceanrep.geomar.de/id/eprint/22955/1/Dissertation_Master_for_print_final.pdf

In this thesis, population genetic structures and evolutionary aspects of speciation in notothenioid fishes from the Southern Ocean have been investigated. Special emphasis was given to the role of pelagic larval dispersal on gene flow between geographically separated populations, since notothenioids are characterized by unusually long pelagic larval durations of up to one year, which is assumed to counteract genetic divergence of populations and ultimately allopatric speciation processes. By elucidating the population genetic structures of selected notothenioid species, inferences were made about the level of gene flow between populations. The major goal of this thesis was to compare the population genetic structures of sympatric species within the Atlantic sector of the Southern Ocean to determine factors responsible for regulating gene flow. Species-specific traits, such as larval durations, were expected to result in differences between the observed patterns, while environmental factors, such as oceanographic currents or frontal systems, were assumed to influence multiple species in a similar way. In addition, it has been tested whether the evolution of notothenioids fulfills the criteria of an adaptive radiation, of which only a few examples are known from the marine realm.