Immigrant and extrinsic hybrid inviability contribute to reproductive isolation between lake and river cichlid ecotypes

Rajkov, Jelena and Weber, Alexandra Anh-Thu and Salzburger, Walter and Egger, Bernd. (2018) Immigrant and extrinsic hybrid inviability contribute to reproductive isolation between lake and river cichlid ecotypes. Evolution: international journal of organic evolution, 72 (11). pp. 2553-2564.

[img] PDF - Published Version
Restricted to Repository staff only


Official URL: https://edoc.unibas.ch/67913/

Downloads: Statistics Overview


Understanding how reproductive barriers evolve and which barriers contribute to speciation requires the examination of organismal lineages that are still in the process of diversification and the study of the full range of reproductive barriers acting at different life stages. Lake and river ecotypes of the East African cichlid fish Astatotilapia burtoni show habitat-specific adaptations, despite different levels of genetic differentiation, and thus represent an ideal model to study the evolution of reproductive barriers. To evaluate the degree of reproductive isolation between genetically divergent lake and river populations, we performed a mesocosm mating experiment in a semi-natural setting at Lake Tanganyika. We assessed reproductive isolation in the presence of male-male competition by analyzing survival and growth rates of introduced adults and their reproductive success from genetic parentage of surviving offspring. The genetically divergent river population showed reduced fitness in terms of survival, growth rate, and mating success in a lake-like environment. Hybrid offspring between different populations showed intermediate survival consistent with extrinsic postzygotic reproductive barriers. Our results suggest that both prezygotic (immigrant inviability) and postzygotic reproductive barriers contribute to divergence, and highlight the value of assessing multiple reproductive barriers acting at different stages and in natural contexts to understand speciation mechanisms.
Faculties and Departments:05 Faculty of Science > Departement Umweltwissenschaften > Integrative Biologie > Evolutionary Biology (Salzburger)
UniBasel Contributors:Salzburger, Walter
Item Type:Article, refereed
Article Subtype:Research Article
Note:Publication type according to Uni Basel Research Database: Journal article
Identification Number:
edoc DOI:
Last Modified:17 Feb 2020 16:37
Deposited On:09 Oct 2019 12:20

Repository Staff Only: item control page