RESEARCH ON DURATION OF CRAWFISH CHANGE OF COAT IN THE LAKE MOSTOVOE OF THE ALTAY TERRITORY

Abstract

The article represents the data of field experiments on the population of crawfish in the Lake Mostovoe of Zavyalovskiy district in the Altay Territory in 2010-2014. The authors summarize the data on commercial stock of bioresources in the basins of the Altay Territory and exactly in the Lake Mostovoe for 8 years. The authors collected the data on temperatures in the investigated district from 2010 to 2014; they revealed the periods of accumulation of total active temperatures. The paper shows the dynamics of size and sex structure of crawfish population in the Lake Mostovoe and specifies the correlation between the size groups according to the sex of crawfish. The authors focus on description of the periods and duration of crawfish change of coat. They point out the dependence of makes’ change of coat periods on the sex of crawfish and temperature. The temperature of water enforces the first change of coat of males and immature females as it starts after accumulation of 500 degree-days. The first change of coat of mature females occurs in the first part of July. Further changes of coat were observed at intervals 30-45 days and they depended on the size of concrete crawfish. Crawfish males and females with length more than 150 mm had the only change of coat during the vegetation period.