An integrative approach highlights the discrepancy in the genetic, phenotypic, and presumptive taxonomic structure of Phoxinus (Actinopterygii, Leuciscidae, Phoxininae) in Bulgaria

Palandačić, Anja (author), Diripasko, Oleg A. (author), Kirchner, Sandra (author), Stefanov, Tihomir (author), Bogutskaya, Nina G. (author)

The present drainage network of Bulgaria is the result of a complex Neogene and Quaternary evolution. Karst, which has developed on 23% of the territory, further complicates the hydrological pattern. Fresh waters of Bulgaria drain into the Black Sea and the Aegean Sea basins and can be roughly divided into the Danube (Middle and Lower Danube), non-Danube Black Sea, East Aegean, and West Aegean hydrological regions. Phoxinus, a small leuciscid fish, has a mosaic distribution in all four of these regions, inhabiting small mountainous and semi-mountainous streams. Based on morphology, it was identified as three species, Phoxinus phoxinus in the Danube, Phoxinus strandjae in the non-Danube, and Phoxinus strymonicus in West Aegean region. Later, molecular data revealed Phoxinus csikii and Phoxinus lumaireul in the Middle Danube and P. csikii in the Lower Danube. Phoxinus has been the focus of many studies, showing a high molecular and morphological diversity, which is not entirely consistent with previous morphology-only-based taxonomic concepts. In this study, molecular (a mitochondrial marker and a nuclear marker) and morphological data from both historical and recently sampled collections were analysed to assess the applicability of the integrative approach in Phoxinus. The results showed a significant influence of the complex paleo- and recent hydrology on the currently observed genetic structure of the considered populations and species. Furthermore, the study also demonstrated a strong influence of phenotypic plasticity on the morphological analysis of Phoxinus and the lack of a clear differentiation between P. csikii and P. strandjae. A barcoded specimen was designated as neotype to fix the species named P. strandjae in the current taxonomic concept. Finally, a significant discordance between genetically delimited clades and phenotypic groups did not allow a proper delineation of the species distributed in Bulgaria, demonstrating that more molecular markers are needed for further taxonomic study of the Phoxinus complex.

• Language: English
• Keywords: common minnow, genetic markers, morphology, taxonomy, variations
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: Str. 214-238
• Numbering: Vol. 105, iss. 1
• PID: 20.500.12556/RUL-175979
• UDC: 59
• ISSN on article: 0022-1112
• DOI: 10.1111/jfb.15765
• COBISS.SI-ID: 255901699
• Publication date in RUL: 17.11.2025

Record is a part of a journal

• Title: Journal of fish biology
• Shortened title: J. fish biol.
• Publisher: Wiley, Fisheries Society of the British Isles
• ISSN: 0022-1112
• COBISS.SI-ID: 25741568

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Projects

• Funder: FWF - Austrian Science Fund
• Project number: I 4131-B25

• Funder: FWF - Austrian Science Fund
• Project number: M2183-B25