REVIEW OF SOME ECOLOGICAL ASPECTS OF STERLET (ACIPENSER RUTHENUS LINNAEUS, 1758)

The article presents the review of scientific works on ecology and biology of sterlet aspects of its distribution, spawning, migration, feeding and accumulation of heavy metals in organs and tissues. It has been stated that in natural populations there are two morphs - with a sharp (long) and blunt (short) rostrum. It has been assumed that they are characterized by the separation of spawning period into time intervals. In artificial aquaculture sterlet individuals show a decrease in morphometric traits, which may result from the identical farming conditions or the reduction of genetic diversity. The background color of the tanks used for cultivation can affect the linear-weight characteristics of fish: in light colored tanks there are fish of smaller sizes, in dark colored ones - fish of larger sizes. It has been found that the color of the species body similar to the bottom substrate acts as s a highly effective protection against predators in turbid waters. The study of sterlet population of in the Ob’-Irtysh and Yenisei basins showed that the former population has a higher genetic diversity index. Migration length of sterlet is insignificant: up to 250 km. It spawns in the spring-summer period, in winter period it concentrates in the wintering holes. The leading role in sterlet feeding belongs to the representatives of benthos and zooperiphyton, which are characteristic of lithophilic, lythoreophilic and psammoreophilic biocenoses. Maximum concentrations of heavy metals have been registered in the liver and gills, minimal in the muscles. The largest accumulation of elements is noted for Fe, Al and Zn, the minimum for Cd and Co.