Situation of the increasing pressure of genetic abnormalities in a diploid-polyploid of population spined loaches (Cypriniformes, Cobitidae, Cobitis )

Genetic monitoring of a diploid-polyploid population of spined loach (Cobitis taenia s. lato) in the Irpen R. (tributary of the Dnieper R., Kiev Region, Ukraine) revealed unusually abrupt changes of its biotype structure during the research period of 2001-2013. As a result, individuals if C. 2 elongatoides-tanaitica biotype with abnormal allozyme spectrum became completely dominant in this population. Simultaneously, individuals of this population also demonstrated a sharp increase in the number of binuclear erythrocytes. All these negative genetic processes occurred during the population decline in the studied river, which indirectly indicates a slight decrease in adaptive abilities of the population specimens.