Natural Hybridization in Spined Loaches of the Genera Cobitis and Sabanejewia (Cobitidae)

A detailed description of the phenotypically hybrid spined loach caught in the Malyi Kyzylagachskii Bay is given in comparison with the three known species of loach fish from the Bay basin: the Caspian spined loach Sabanejewia caspia, Cobitis saniae, and the Khvalynskaya spined loach C. amphilekta. Hybridization of the first two species supported by their sympatry, overlapping spawning periods, and a noticeable difference in numbers in co-inhabited biotopes is confirmed. The extremely low frequency of hybridization of the Caspian spined loach and C. saniae is explained by the significant differences in the ecology of spawning and in the spawning behavior of the two species.