编号 6 (2023)

The evolutionary history of North Atlantic Sebastes redfishes was reconstructed as a result of studying the mitochondrial DNA D-loop sequences of Sebastes redfishes inhabiting the North Atlantic and the Arctic Oceans. It was shown, that speciation of these redfishes occurred in several stages. During the first stage, the ancestor of Norway redfish (S. viviparus) diverged from the common ancestor species in the process of allopatric speciation. Ancestor of Acadian redfish (S. fasciatus) diverged from the common ancestor as it evolved. Budding speciation in the species that would later evolve into golden redfish (S. norvegicus) resulted in emergence of beaked redfish (S. mentella). Paleoclimatic events seem to have played the key role in species divergence as they caused habitat fragmentation allowing the isolated groups to become genetically distinct in the meantime. The conducted analysis of Sebastes redfishes speciation brings into question the generality of widely accepted views on fish sympatric speciation. It also serves as an argument against the molecular clock hypothesis.

The use of lignosulfonates (LS) to improve soil fertility is currently under study and discussion. The effect of sodium LS application in the sandy loam soil on the accumulation of biomass, photosynthesis, respiration and their coupling in cucumber plants was studied. The LS rate of 10–25 g/kg did not have a significant effect on the studied parameters of the physiological state of plants. However, at a high LS content (50–100 g/kg), the plant growth rate and activity of the photosynthetic apparatus decreased, and the respiration rate increased, which caused the increase in the ratio of respiration to photosynthesis. The negative effect of high concentrations of LS on the physiological state of cucumber plants and their cold resistance is presumably associated with sodium salinization of the soil.

The association of degradation of membrane-bound chlorophyll with changes in dark respiration rates and photosynthesis in Festuca arundinacea Schreb. leaves under the influence of various concentrations of limit and aromatic hydrocarbons present in technogenic emissions was studied. 1 day after intoxication a negative correlation between the content of non-phytol forms of pigments and the rate of photosynthesis was found. Positive correlation was found between the content of: 1) phytol forms and the rate of photosynthesis; 2) non-phytol forms and respiration rate. The relationships between the processes changed after 3 days characterizing the detoxifying and adaptability of plants.

It was found that the variability of additional elements in the posterior part of the first and second upper molars in L. gregalis forms a morphological module with a hierarchical structure. This module is designated as an atypical form (Atypical Form), and its phenotype as AF. The phenotype of the typical form is designated as tf (typical form). The main component of modular variability is an increase in the frequency of individuals with AF phenotype with age. The severity of this phenotype also increases with age. The presence of the AF phenotype in individuals is determined monogenously. Individuals with the AF phenotype are dominant heterozygotes or homozygotes. Which phenotype (tf or AF) the dominant heterozygote implements may depend on the influence of modifier genes. The revealed morphological module of the presence of additional elements in the posterior part of the first and second upper molars has a genetic basis.

Animal circadian activity was mostly studied in captivity with artificial environment. We performed pioneer study of daily activity using telemetry for yellow ground squirrels (Spermophilus fulvus), burrowing hibernating rodents. Eight individuals were fitted with glued-on radio transmitters contained accelerometers and light sensors in the wild colony in 2021. Our data showed that S. fulvus was strictly diurnal and active aboveground only during daytime. The squirrels ceased locomotor activity and rested when they entered their burrows. As the season progressed, the duration of aboveground activity decreased. In contrast to similar species with peaks of aboveground activity in the morning and in the evening, yellow ground squirrels didn’t break the activity in midday. Probably, prolonged hibernation and, therefore, time deficiency induced S. fulvus to use day hours as effective as possible.

We studied the humoral innate immune responsiveness (HII), i.e. a hemolysis of rabbit erythrocytes by complement proteins, and adaptive humoral (antibody production) immune responsiveness (AHI) to SRBC, morphological and hormonal reproductive characteristics and stress level in male Campbell hamsters kept under long-day (LD; 16D: 8N) and short-day (SD; 8D: 16N) photoperiods. The results indicate lower HII, but not AHI in SD. In SD males we observed body mass, anogenital distance, midventral gland size and level of testosterone in the peripheral blood (but not the level of cortisol) decreased. Comparison of SD non-responders, SD responders and LD individuals demonstrated a statistically significant increase of HII in SD photosensitive hamsters, but not in non-responders compared to LD. There was no link between HII and AHI, which indicates an independent photoperiodic responsiveness of different branches of the immune system in Campbell’s hamster.

The ability of the autochthonous microbiota of different water bodies in the North-West of the Russian Federation to degrade the highly toxic microcystin-LR (MC-LR) was shown for the first time. The maximum rate of degradation of MC-LR was noted in water samples from the Sestroretskij Razliv Lake and the Lower Suzdal Lake during the period of mass development of cyanobacteria. In water samples from Lake Ladoga, where no toxic cyanobacterial blooms were previously noted, MC-LR biodegradation proceeded at a much lower rate and with a longer lag phase. The composition of MC-LR biodegradation products indicates the presence in the autochthonous microbiota of the studied objects of microorganisms capable of degrading microcystins both by the mlr mechanism and by the biochemical pathway involving glutathione.

The features of the ecology of brambling at the northern limit of their range in the Priobskaya forest tundra are considered. The nesting density remains high, locally 50–100 pairs/km², up to the boundary of the distribution of coastal forests and floodplain woodlands along the 67th parallel. Habitats suitable for nesting brambling are also available to the north, but birds are few in number. Biotopic conditions do not significantly limit the progress to the north. The brambling have no adaptations to Subarctic conditions. This is a medium- and north-taiga species that develops the forest tundra as it warms and thickens the woodlands.

An electron microscopic study of the teguments of the late acanthella and the cystacanth acanthocephalan Acanthocephalus tenuirostris obtained in the experiment was carried out. The late acanthella is characterized by a bilayer cyst and signs of intense secretion in the surface part of the tegument. A cystacanth is characterized by a cyst and a thick layer of glycocalyx on the surface of the tegument, which are closely adjacent to each other along their entire length. During the preparation of some cystacanths, the cyst received mechanical damage; in these cystacanths, shedding of a thick layer of glycocalyx and associated cyst was observed.