Variability in the life strategy of dolly varden char Salvelinusmalma (Salmonidae) from the mouth of the Urak and Ohоta rivers (Khabarovsk territory) based on biological characteristics

Abstract

The paper presents the results of comparison of Dolly Varden char (malma) from the mouth of the Urak and Okhota rivers of Khabarovsk Territory. The following biological traits were analysed: age, size composition, linear and mass growth, reproductive biology, the type and occurrence of injuries, CPUE. The fish from Urak River, compared to Okhota River malma, are characterized by an increased size and age range, high growth rates, increased GSI and fecundity. Reduced growth and fecundity of malma from the mouth of the Okhota River may be related to the fact that it was the dominant species in the catches, which may indicate a high level of competition for food resources. In contrast to fish from the Okhota River, malma from the Urak River had injury patterns similar to those of pink salmon. This may indicate differences in the life histories of fish from the studied rivers: malma collected from the Urak River has traits of the anadromous form, while fish from the Okhota River can be considered as resident. Our data fill the existing gaps in knowledge on the biology and ecology of malma from the rivers of the Northern coast of the Sea of Okhotsk.