Charrs of the genus Salvelinus (Salmonidae): hybridization, phylogeny and evolution

Abstract

Evolutionary history, systematics and taxonomy of charrs of the genus Salvelinus and especially of the representatives of the S. alpinus -S. malma species complex remain confused that is connected with a substantial ecological and morphological flexibility of this group and with supposed ancient hybridization between some taxa. For the analysis of phylogenetic relationships and introgressive hybridization between the species of the genus Salvelinus including three endemic species from Lake El'gygytgyn and all main representatives of the S. alpinus -S. malma species complex, nucleotide sequences of mtDNA control region (960 bp) and two nuclear genes (ITS1 (581 bp) and RAG1 (899 bp)) were analyzed. The differences in the topologies of individual gene trees, among others reasons, were connected with incomplete lineage sorting and historical introgressive hybridization between certain taxa. Several cases of mtDNA capture by different taxa and phylogenetic groups were proposed. In particular, the following taxa participated in introgressive hybridization: northern Dolly Varden S. m. malma, representatives of the S. alpinus complex (including mainly Taranets charr S. a. taranetzi), southern Dolly Varden S. m. lordi from North America and bull trout S. confluentus. Main phylogenetic groups of the S. alpinus -S. malma species complex were revised. The origin and phylogenetic relationships of southern Dolly Varden from North America were not unambiguously defined. We proposed that introgressive hybridization had an important role in the evolutionary history of charrs, in particular, in the appearance of a high level of morphological, ecological and taxonomical diversity.

Fatty Acid Composition and Contents of Fish of Genus Salvelinus from Natural Ecosystems and Aquaculture

“…For instance, in spite of nearly similar FA composition and contents of diets, farmed S. alpinus and S. fontinalis had significantly different levels of 18:1n-9, ∑20:1, and 20:5n-3. These differences might be determined genetically, because S. fontinalis is known as the most diverged species of genus Salvelinus [ 59 ].…”

Peer Review #1 of "Genetic structure of marine and lake forms of Pacific herring Clupea pallasii (v0.1)"

“…This type of selection often contributes to the expansion of a subset of phenotypic traits and the formation of evolutionary innovations (Hunt et al 2011;Lahti et al 2009;Snell-Rood et al 2010). This type of shaping is shown in various teleost species such as barbs (de Graaf et al 2010;Levin et al 2020), Sevan trout (Levin et al 2018), Arctic char (Alekseyev et al 2002;Osinov et al 2021), and cichlids (Barluenga et al 2006;Kautt et al 2020). At the same time we suggest that the geographic separation and glaciation during Pleistocene does not explain our findings, since the lake forms are genetically close to each other, but geographically distant.…”

Genetic structure of marine and lake forms of Pacific herring Clupea pallasii

“…This type of selection often contributes to the expansion of a subset of phenotypic traits and the formation of evolutionary innovations ( Hunt et al, 2011 ; Lahti et al, 2009 ; Snell-Rood et al, 2010 ). This type of shaping is shown in various teleost species such as barbs ( De Graaf et al, 2010 ; Levin et al, 2020 ), Sevan trout ( Levin et al, 2018 ), Arctic char ( Alekseyev et al, 2002 ; Osinov, Volkov & Mugue, 2021 ), and cichlids ( Barluenga et al, 2006 ; Kautt et al, 2020 ). At the same time we suggest that the geographic separation and glaciation during Pleistocene does not explain our findings, since the lake forms are genetically close to each other, but geographically distant.…”