Развитие осевой локомоторной мускулатуры у половозрелого окуня-клювача Sebastes mentella (Sebastidae)

Abstract

The results of the study of the histological structure of the locomotor axial (skeletal) muscle tissue of the beaked redfish Sebastes mentella are presented and its ontogenetic changes are considered. Its skeletal muscles compose of glycolytic (white) and oxidative (red) fibers. Data show the quantitative distribution of these fibers along the body of sexually mature fish in the cranio-caudal direction, their ratio in the trunk and tail parts. The diameter of these two types of fibers reaches significant sizes, as in a number of deep-sea slow-growing species (> 300 μm - white fibers, > 150 μm - red fibers). The density of glycolytic fibers is higher than that of red ones (80,7±2,0 versus 54,7±1,5 %), which is due to the different content of adipose and connective tissue (endomysium). The variability of white fibers in most fish size groups is significantly lower than that of red ones. A feature that is not noted in other deep-sea fish species with a low growth rate is the relatively frequent occurrence of red fibers with stratification of sarcoplasm into two zones (layers) - external and internal (double structures), the nature of which is not yet clear.