Identification and characterization of hybrids of Acipenser ruthenus and Acipenser baerii (Actinopterygii, Acipenseriformes) from the Irtysh River

Two sturgeon species, Acipenser ruthenus (Linnaeus, 1758) and baerii (Brandt, 1869), inhabit the Irtysh basin. In 2018, we received some “atypical” specimens of sturgeon, which were similar to A . but had a number pronounced external differences. The hybrids A. × , named “oster”, can sometimes be caught in natural habitats Ob Yenisei rivers. Despite development methods for genetic identification sturgeons, molecular characteristics have not been carried out. purpose this study is develop complex morphological characters identify hybrid from River. We used compare putative with parental species dorsal scutes, rays anal fins, structure stamens on first gill arch, presence fringe tendrils. size weight values, lateral ventral rakers arch. Genotyping by using Inter Simple Sequence Repeat (ISSR) markers revealed sites characteristic both species. fragment control region mitochondrial DNA matched that allowed us females as maternal individuals hybrids. Possible causes factors promoting interspecific hybridization studied. This described fact appearance Ob-Irtysh It necessary continue monitoring studies these ecological system data set