ХАРАКТЕРИСТИКА РАЗМЕРНЫХ ПАРАМЕТРОВ МОЛОДИ СТЕРЛЯДИ (ACIPENSER RUTHENUS L. 1758) РЕКИ ИРТЫШ (УВАТСКИЙ РАЙОН)

Abstract

The article gives the description of dimensional parameters (absolute length, body weight, plastic characters) of young sterlet in the Irtysh River (the Tyumen region, Uvat district). The state of the population was assessed according to the description and a comparative analysis 
 of data obtained by measuring individuals of sterlet from other reservoirs and water areas. Characteristics of young sterlet growth at the age of 1+ and 2+ were also given. It has been stated that starlet juveniles in the Irtysh River are exposed to the local environmental conditions (water temperature, adequate food reserve), which is expressed in a significant variability of the species growth rates in each age group. The results of the analysis of the mass values of sterlet species from different water areas and habitats confirm that sterlet is a plastic species. When analyzing the plastic features of sterlet juveniles, there has been observed the uneven growth of body parts, which can be seen in the variability of parts of the head, size of fins and body weight, followed by the growth of fish and its transition to older age groups. It is noted that significant differences between species from different water areas do not tend to be distributed in latitude or longitude, and sterlet grown under aquaculture conditions does not prevail in all parameters over wild individuals, which suggests the presence of any influence on the growth rate of sterlet by almost the entire habitat including the studied sterlet population.