Quaternary geomorphological and climatic changes associated with the diversification of Iberian freshwater fishes: The case of the genus Cobitis (Cypriniformes, Cobitidae)

Abstract

We studied the population genetic structure of Cobitis vettonica , an endangered freshwater fish species endemic to the Iberian Peninsula, in order to propose a biogeographic model of the responses of species to the multiple changes that occurred in the Iberian hydrological system during the Quaternary period. We also deciphered the relationship of C . vettonica with its sister species C . paludica , particularly in sympatric areas, and provide genetic information for conservation purposes. To achieve this goal, we analyzed both mitochondrial and nuclear data (the cytochrome b and the nuclear recombination activating 1 genes) and a battery of single‐nucleotide polymorphisms (SNPs) of 248 individuals of C . vettonica or C . paludica from 38 localities, including some sympatric ones, covering the entire distribution area of C . vettonica . We highlight the important role played by the hydrogeomorphological processes and climatic changes that occurred in the Iberian Peninsula during the Quaternary on both the population structure of C . vettonica and its relationship with its sister species C . paludica . Our results support the genetic introgression of populations at the eastern limit of the distribution of C . vettonica . Furthermore, we postulate genetic introgression in sympatric areas. Finally, we propose the establishment or expansion of four Operational Conservation Units (OCUs) for C . vettonica , and highlight the threat faced by its populations due to the low level of genetic diversity detected for some of its populations and genetic introgression with C . paludica , which could eventually displace C . vettonica , resulting in a loss of diversity in this species.

Environmental DNA metabarcoding of water samples as a tool for monitoring Iberian freshwater fish composition

“…The selection of species for the 12S reference database was based on previous knowledge of the ichthyofauna inhabiting the Duero Basin and genetic population structure studies [ 39 – 41 ]. The following 26 species (25 species present in Spain and Luciobarbus rifensis Doadrio, Casal-Lopez & Yahyaoui, 2015 from northern Morocco) were included in the database: Achondrostoma arcasii ; A .…”

“…The selection of species for the 12S reference database was based on previous knowledge of the ichthyofauna inhabiting the Duero Basin and genetic population structure studies [39][40][41] First, we downloaded all available 12S sequences of the selected species from GenBank, which totaled 149. To these, we added the 12S sequences of 78 specimens belonging to 19 species whose tissue had been previously sampled and stored in ethanol in the DNA and Tissue Collection at the National Museum of Natural Sciences of Madrid (MNCN-CSIC) (S1 Table in S1 File).…”

“…Primary freshwater fishes (i.e., whose ancestors entered inland waters much earlier, cannot survive in seawater and are thus strictly confined to fresh water) [29][30][31] of the Iberian Peninsula have been widely studied in a phylogenetic and phylogeographic context [e.g., [32][33][34][35]. All phylogenetic and phylogeographic studies in Iberian primary freshwater fishes have been conducted using the MT-CYTB and COI markers, while no surveys have been carried out with the 12S marker [36][37][38][39][40][41]. In fact, unlike for the other markers, there is no 12S database for native Iberian freshwater fishes.…”

“…Duero Basin also harbors a great intraspecific genetic diversity for multiples native Iberian freshwater fish species, as revealed by multiple population genetics surveys [32,40,41]. On the one hand, for several species within this basin that are also distributed in other Iberian basins, such as Cobitis vettonica (Doadrio & Perdices, 1997) [57], Squalius alburnoides (Steindachner, 1866) [58] and S. carolitertii (Doadrio, 1988) [59], population genetics studies have revealed that Duero Basin populations behave as an independent evolutionary lineage [40,60,61].…”

Description of three new species of the genus Cobitis L., 1758 (Actinopterygii, Cobitidae) in the Iberian Peninsula

“…Palabras clave: taxonomía, península ibérica, Cobitis, Cypriniformes, Cobitidae, genética, morfología This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License. has been reported along low stretch rivers of the Tagus basins (Corral-Lou et al, 2022). The divergence of C. vettonica and C. paludica was calibrated to 5.3 ± 1.6 MYA, i.e., which was the end of the Miocene and Pliocene (Perdices & Doadrio, 2005).…”