Jernej Bravničar: Evolution & phylogeny of trout & grayling, and conservation in the Soča River
Channel: Fishbase Sweden
Date: 08/11/2022

Jernej Bravničar, University of Ljubljana, Slovenia, gave a talk on "Evolutionary and phylogenetic aspects of trout and grayling in Europe in the genomic era, with highlight on salmonid conservation and management in the Soča River", FishBase Symposium 2022, Stockholm, Sweden, 17 October 2022.

ABSTRACT: Salmonids are considered "recent" colonizers of the European continent when compared to the Cypriniformes. Historically thoroughly studied, mostly because of economic importance, their taxonomy and phylogeny are constantly under review. As new research tools are applied, new hypotheses emerge that shift the phylogenetic relationships among the taxa under study.
 
The “true” phylogenetic signal is naturally blurred by periodic range shifts, local extinctions, and recolonizations, while at the same time it’s severely compromised by constant translocations and intensive population management. The genomics era has seen the discovery of numerous tools, including those that allow us to analyze museum specimens, thus providing unique opportunity to study the populations before major translocations and subsequent hybridizations. However, despite the great utility of genomic tools for taxonomy and phylogeny, the following questions arise: How can the findings of genomics be related to findings of genetics and morphology; can phylogenomics be the holy grail of taxonomy; what pitfalls can be expected in future studies?
 
Because the peri-Mediterranean basin harbors great trout diversity, it may prove to be a perfect testing ground for using genomic tools to uncover trout taxonomy and phylogeny and answer these questions. In the talk we will address the discrepancies observed when considering phylogeny at different levels of resolution within European salmonids, focusing on the position of Salmo marmoratus, a species whose most important morphological trait could be considered plesiomorphic in certain cases. In addition, we will address the tools that can be used for the conservation management of the species, while trying to get by the fact, that trout have a major ecological advantage over grayling in terms of conservation efforts. This disadvantage complicates the possibilities for genetic rescue of the highly endangered Adriatic grayling (Thymallus thymallus) in the fly-fishing paradise of Soča river, but genomics will provide the basis for its restoration, hopefully as successful as was that of the marble trout.