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No 5 (2023)
Articles
ECOLOGICAL ASPECTS OF EXPERIMENTAL GROWING OF YOUNG MUKSUN IN THE NATURAL ENVIRONMENT
Abstract
The feeding characteristics of juvenile muksun Coregonus muksun (Pallas, 1814) when reared in cages installed on the Lower Ob channel are considered. It has been established that, along with artificial food, juveniles feed on zoobenthos and zooplankton organisms that enter the cages during drift. Their consumption was noted from the first to the last days of growing. The bulk of the mass of the food bolus was artificial food – 88.3–94.3%; aquatic invertebrates accounted for 1.3–5.7% of the mass of the food bolus. Chironomid larvae dominated. There were no statistically significant differences in the consumption of invertebrate animals by muksun juveniles before and after feeding (p = 0.442) with average values of 0.005 and 0.006 g, respectively. The ability of juveniles to transition from artificial to natural food supply at all stages of development was noted, which is an indicator of successful adaptation to environmental conditions during cage rearing in the channels of the river Obi.
325-337
MORPHOGENETIC CONSEQUENCES OF SHORT-TERM HEAT STRESS IN SHORT- AND LONG-LIVED LINES OF THE HOUSE FLY (MUSCA DOMESTICA L.): WING GEOMETRIC MORPHOMETRY
Abstract
The morphogenetic consequences of short-term heat stress (SHS) were studied in two housefly lines that were massively selected for lifespan based on assessing the variability of the adult wing using geometric morphometry methods. Significant differences in wing size and shape were revealed between control and impact groups of different sexes in the Shg (short-lived) and Lg (long-lived) lines. The CTS effect manifested itself in an increase in the size of the wing and a directional change in its shape. The intergroup hierarchy of sex and stress-induced differences is expressed equally in both strains of flies. The range of linear differences is significantly higher than gender differences, which in turn are higher than the level of stress-induced ones. The instability of the adult wing development (Vm) of the Shg line is significantly higher than that of the Lg line, and higher in all groups of females, but in most cases significantly lower in impact groups (taking into account the increase in size, the latter may be associated with the effect of hormesis). It is hypothesized that the directed morphogenetic effects of CTS are based on hidden species-specific modifications, the appearance of which in the phenotype is caused by stress-induced epigenetic rearrangements of the genome, causing similar morphological changes in the wing in groups of males and females of adults of both lines. The phenotypic plasticity of lines during selection for different life spans and changes caused by CTC directly indicate the reality of stress-induced rapid morphogenetic rearrangements during a sharp change in environmental conditions.
338-355
Trophic selectivity of the barnacle goose and the white-fronted goose in the area of reproductive concentration
Abstract
Against the backdrop of intense transformation of the Arctic environment and biota, differences in population trends of massive and widespread herbivores in the Arctic are of great interest. In this regard, the main goal of our work was a comparative assessment of the trophic selectivity of the barnacle goose and the white-fronted goose under conditions of the largest reproductive concentration, characterizing the role of competition in the dynamics of their populations. It has been shown that the differences in the quantitative ratio of plants eaten by these species are not sufficient to avoid competition, and that the most selective, i.e. The food of the barnacle goose is sensitive to quality and energy-consuming. However, its status as a relatively weak competitor belies the exponential growth of its population in the study area and the entire Arctic population. We believe that differences in the population dynamics of the barnacle goose and the white-fronted goose are currently not due to competition during reproductive concentrations, but to the influence of anthropogenic and climatic factors far beyond the breeding range.
356-364
RESIDENTS AND NON-RESIDENTS: DAILY ACTIVITY OF SMALL MAMMALS IN CONTRASTING BIOTOPES
Abstract
Using the marking and recapture method, we compared the daily activity of four common species of small mammals of the forest zone in three biotopes that differ greatly in their protective properties. Lines of live traps were installed in a dark coniferous forest, on a grassy slope and along a rocky beach along the water's edge on the river. Ilych. The activity of resident and non-resident individuals was assessed with a frequency of checks every 1.5 hours. In the forest, polyphasic activity without pronounced maxima was noted for all species; on the open slope, the maximum activity of resident animals occurred at night, and on the shore only non-resident animals were observed. Non-resident activity in all biotopes is shifted to the night, while in open biotopes the period of activity is shorter and more associated with the dark time of day.
365-374
The potential of using the Blue Intensity parameter to assess the climate response of radial tree growth on the Crimean peninsula
Abstract
The results of assessing the climate signal contained in the width of tree rings and the indicator of optical density of wood (Blue Intensity) of related species of pine trees – black (Pinus nigra Arnold) and Pitsunda (Pinus brutia Ten) growing on the southern coast of the Crimean peninsula are presented. The influence of the cumulative effect of moisture deficiency on the radial growth and lignification processes of late wood of the studied conifer species is shown. A specific reaction of P. nigra in high mountain areas to conditions of prolonged drought was revealed. The prospects for using the Blue Intensity indicator for dendroclimatic studies on the territory of the Crimean Peninsula have been demonstrated.
375-386
КРАТКИЕ СООБЩЕНИЯ
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