Scientific publications

The activity of lysosomal enzymes in juveniles of the three-spined stickleback Gasterosteus aculeatus L. from three biotopes of the Kandalaksha Gulf of the White Sea (Seldyanaya Inlet, Kolyushkovaya Lagoon, Sukhaya Salma Strait), differing in temperature regime, salinity, water exchange rate, density of aquatic vegetation, and other parameters, was studied. Fry for research was caught twice during the summer period: at the end of July and in August. In the samples, the activity of six acid hydrolases (acid phosphatase, RNase, DNase, β-glucuronidase, cathepsin B and cathepsin D) was determined. Some differences were revealed in the activity of the studied enzymes in the tissues of developing stickleback fry from different biotopes and depending on the time of sampling. The acid phosphatase activity in fry from all water areas practically did not depend on the sampling time. At the same time, the level was significantly higher in the samples from Kolyushkovaya Lagoon taken in August. The RNase activity was the highest in fry from all three biotopes captured in August compared to those taken in July, which indirectly indicates the intensive biosynthesis processes in growing juveniles of fish during this period. A noticeable increase in DNase activity in the group of juveniles from Sukhaya Salma caught in August suggests that they include more long-term mechanisms of adaptive metabolic rearrangements that affect the genome. Judging by the size-mass characteristics, this group is represented by fry of a later generation compared to groups from other biotopes, and they have recently completed morphogenetic transformatios associated with the transition to the juvenile period of development, in which lysosomal enzymes are involved. Compared to those from other biotopes, juveniles from Kolyushkovaya Lagoon have a relatively higher activity of β-glucuronidase and cathepsin B. Both of these enzymes are involved in the synthesis of components that regulate metabolism. It can be assumed that the main factor causing the need to adjust the metabolism of juvenile fish by August in the Kolyushkovaya Lagoon is the diversity and abundance of food components in this biotope. Thus, the active participation of lysosomal hydrolases in the adaptive metabolic rearrangements of stickleback fry under the influence of abiotic (temperature, salinity, tidal cycles) and biotic (feeding patterns) environmental factors has been shown.