Morphological characteristics, reproduction, and food habits of European bitterling Rhodeus sericeus amarus (Cyprinidae) in the Alatyr River

The data on the morphology, reproduction, and diet of European bitterling Rhodeus sericeus amarus in the Alatyr River (the Sura tributary) are presented. Differences between females and males have been revealed with respect to the complex of morphometric characters. It is assumed that the deviations of some meristic characters from those that are typical of European bitterling are due to the habitation of this population at the boundary of the species distribution. The species reaches sexual maturity at the age of 1–2 years; the individual fecundity is 103–525 (354) eggs. Bitterling is a typical phytophage.