Variability of Morphological Characters of the Genus Alburnoides (Pisces, Leuciscidae) from Watercourses in Southern Russia

The variability of the morphological characters of the genus Alburnoides Jeitteles, 1861 from watercourses in the south of Russia (five rivers of the Crimean Peninsula and two rivers of the Krasnodar Territory) is considered. It has been established that in spirlins within the study areas, body sizes average from 60.1 ± 1.45 mm in individuals from the river Gostagayka (Krasnodar region) up to 88.2 ± 1.87 mm in fish from the river Angara (Crimean Peninsula). Using the Mann–Whitney test, statistically significant differences were registered between the samples in most plastic characters; they were absent in meristic characters. In the studied regions, heterogeneity in the structure of the genus Alburnoides was noted: according to the results of cluster analysis for the totality of all studied characters, the greatest similarity was found in samples from Crimean rivers that are geographically close to each other (rivers Chernaya, Belbek, Kacha and Alma), but group from the river Angara adjoins them at a higher level of divergence. A separate group is formed by samples from the rivers of the Krasnodar Territory. The obtained data are consistent with the literary information on the formation of the ichthyofauna in the rivers of Crimea; the established clear differences between the charaters from the rivers of southern Russia require a more detailed study.