LOST IN KARST: EVOLUTION OF DINARIC ENDEMIC FISH FAUNA

Applicant: Nina Bogutskaya, co-applicant: Ernst Mikschi, Natural History Museum Heterogeneous karst landscapes create a variety of habitats, which are among the least known ecosystems on the planet, giving home to often endemic and endangered species. The uniqueness of the Dinaric (Adriatic basin) freshwater fauna is widely acknowledged. However, it seems unbelievable that we have researches working on cave fishes inhabiting remote places as Mexico or China, but when it comes to European countries, such as Croatia and Slovenia, the study of hypogean fishes, despite their tremendous potential for understanding the processes of evolution, has been largely overlooked. Neither their morphological nor biological adaptations have been examined with regard to their specific habitats in the karst, and very modern molecular studies are going on without fundamental questions answered. The goal of the proposed project is to reach a better understanding of evolution, phylogeny and speciation of this unique model group of assumed-to-be troglophilic fish species. Respectively, the specific objectives of the study are to (1) conduct a comparative morphological study of Dinaric leuciscine fishes and their non-Dinaric closest relatives to garner insights into the yet unknown morphological structures and the possible evolutionary scenarios of adaptation to residence in underground habitats using a diverse set of methods; (2) explore the hitherto completely unknown ontogenetic development of species that include epigean and hypogean populations with a two-fold purpose-to use the ontogenetic criteria for phylogenetic reconstructions and to determine what adaptations are responsible for their thriving in the underground environment; (3) get insights into a morphological diversity of different groups of Dinaric leuciscine taxa containing hypogean populations which provides a unique opportunity to study a concept in evolutionary biology that is only superficially understood: convergent evolution; (4) combine data on morphology, biology and genes in approaching a clear and unambiguous evolutionary scenario based on classical and molecular biology; (5) review the distribution of species in order to re-assess assumed endemicity level of amazing Dinaric fishes which are only locally distributed and heavily threatened by human activities and put forward proposals for their conservation against the approaching extinction. The particular advantage of this project is the unification of historical and recent collection data to establish a link between the historical and modern sets of evolutionary information. The outcomes of the research will improve our knowledge of general patterns and processes underlying evolutionary history of fishes in general and of the unique diversity of the Dinaric Region in particular.

Summary for public relations Project number: M2183-B25 The extraordinary diversity of freshwater fishes has made them an ideal system to integrate major bodies of research on evolution and taxonomy. Heterogeneous landscapes create a variety of habitats, especially the karst, which is among the least known ecosystems on the planet, giving home to often endemic and endangered species. The project aimed to better understand the evolution and speciation of some unique model groups of assumed-to-be troglophilic fishes and neighboring surface populations. Research objectives included the study of problems related to morphological adaptations, phylogeography and evolutionary pathways of leuciscine fishes in the Dinaric Adriatic area. Numerous samples of different species from a variety of groups were examined and analysed from different morphological aspects, with an emphasis to habitat-related traits. A new set of morphometric, meristic, qualitative external and anatomical characters (never used before in most taxa) was designed for individual groups to detect fine-scaled differences on the one hand and evolutionary important transformations on the other. It is a unique material that provided an excellent basis for addressing problems of phylogeny at lower taxonomic levels, phylogeography and speciation. The new morphological data contributed to a sound application of integrative taxonomy (along with genetic data) to complex groups of freshwater fishes characterised by peculiar patterns of genetic and morphological diversity ranging from cryptic species to over-diversified polymorphic species complexes. Some species and phenotypes new for science have been described including those, which are only locally distributed and heavily threatened by human activities. The particular advantage of this project was the unification of historical and recent collection data to establish a link between the historical and modern sets of evolutionary information. The results of the research will improve our knowledge of the general patterns and processes underlying the evolutionary history of fishes in general and of the unique diversity of the Adriatic Region in particular. Three papers were published (two manuscripts submitted and three prepared for submitting in the near future) and four conference talks presented. In addition to the academic interest, the present results provided important impulses for applied topics such as environmental management, nature protection and conservation of animal species.