Biosystems Diversity (E-Journal - Dnipro National University)
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Temperature characteristics of peptidase in chironomid larvae, potential fish prey, at various pH values
Get PDFThe temperature dependence of casein- and hemoglobinlytic peptidases functioning in the whole organism of chironomid larvae Chironomus plumosus, food objects of adult benthophages and juvenile fish of various ecological groups, was studied within the temperature range of 0–70 ºС at different рН values (3.0, 5.0 and 7.4). The method of mixed samples was used to determine the activity and characteristics of enzymes. Homogenates of previously crushed and carefully mixed dozens of larvae were used as enzymatically active preparations. Activity of peptidases was assayed by the increase in tyrosine concentration using the Folin-Ciocalteu reagent. It is shown that the activity of peptidases that function in the tissues of chironomid larvae depends to a considerable extent on temperature and рН, but the pH has a smaller effect on the activity and the temperature dependence of casein- and hemoglobin-lytic peptidases than temperature. The temperature optimum of the studied peptidases of chironomid larvae corresponds to 40 ºС. The Q10 values in the zone of vital temperatures are slightly changed. They are, as a rule, increased in the zone of 30–40 ºС, and are sharply decreased in the zone of high temperatures. The values of activation energy of the process of hydrolysis of casein and hemoglobin in the zone of low and high temperatures are different. The Еact values of the process of hydrolysis of casein and hemoglobin at a temperature not exceeding 20 ºС are usually below those in the zone of higher temperatures (except for hemoglobin-lytic peptidases at pH 5.0). The data obtained indicate a significant effect of pH not only on the activity, but also on the temperature characteristics of peptidases that function in the body of chironomid larvae. Differences in the characteristics of casein- and hemoglobin-lytic peptidases in chironomid larvae at different temperatures and pH can influence the digestion in benthophages and fry of all fish species
Strusture, biomass and production of the biotic component of the ecosystem of an growing eutrophic reservoir
Get PDFUsing our own data and data from the literature, we assessed the total biomass of the biotic component of the ecosystem of the Ivankovo Reservoir (Upper Volga, Russia), a eutrophic reservoir which is becoming overgrown with macrophytes. The biotic component of freshwater ecosystems is formed by communities of multicellular and unicellular organisms and viruses in the water layer (plankton) and bottom sediments (benthos) and also macrophytes and autotrophic and heterotrophic organisms growing on their surface (epiphyton). The biomass of the biotic component of the Ivankovo Reservoir equaled 39,853 tons С. Plankton, benthos and macrophytes with epiphyton equaled 3.6%, 41.6% and 54.8% of the total biomass respectively. We determined the contribution of higher aquatic plants, algae, cyanobacteria, heterotrophic bacteria, viruses, protozoans, multicellular invertebrates and fish to the formation of total biomass. The largest share was taken up by higher aquatic plants (54.5%). The second largest share was taken by heterotrophic bacteria (37.4%), most of which live in the bottom sediments. The high concentration of bacteria and invertebrates in the bottom sediments indicate significant provision of the organic substrates from the water column. The biomass of fish, the highest trophic link in the reservoir, equaled 15.0% of the biomass of their potential food substrates, invertebrate animals, and 0.7% of the total biomass of the biotic component. The greater part of the autochthonous organic compound in the reservoir is formed as a result of activity of phytoplankton, which provides 69.4% of total primary production of macrophytes, phytoepiphyton, phytoplankton and phytobenthos. The total primary production during the vegetation period was approximately forty times higher than the annual production of the fish. Currently, the share in the phytoplankton of large colonial cyanobacteria not consumed by zooplankton, the share of non-heterocystic species of cyanobacteria capable of heterotrophic feeding and the share of mixotrophic flagellates is increasing. Eutrophication of the reservoir is significantly stimulated by the development of macrophytes, and, presumably, the contribution of macrophytes to the total primary production of the reservoir will continue to increase.Using our own data and data from the literature, we assessed the total biomass of the biotic component of the ecosystem of the Ivankovo Reservoir (Upper Volga, Russia), a eutrophic reservoir which is becoming overgrown with macrophytes. The biotic component of freshwater ecosystems is formed by communities of multicellular and unicellular organisms and viruses in the water layer (plankton) and bottom sediments (benthos) and also macrophytes and autotrophic and heterotrophic organisms growing on their surface (epiphyton). The biomass of the biotic component of the Ivankovo Reservoir equaled 39,853 tons С. Plankton, benthos and macrophytes with epiphyton equaled 3.6%, 41.6% and 54.8% of the total biomass respectively. We determined the contribution of higher aquatic plants, algae, cyanobacteria, heterotrophic bacteria, viruses, protozoans, multicellular invertebrates and fish to the formation of total biomass. The largest share was taken up by higher aquatic plants (54.5%). The second largest share was taken by heterotrophic bacteria (37.4%), most of which live in the bottom sediments. The high concentration of bacteria and invertebrates in the bottom sediments indicate significant provision of the organic substrates from the water column. The biomass of fish, the highest trophic link in the reservoir, equaled 15.0% of the biomass of their potential food substrates, invertebrate animals, and 0.7% of the total biomass of the biotic component. The greater part of the autochthonous organic compound in the reservoir is formed as a result of activity of phytoplankton, which provides 69.4% of total primary production of macrophytes, phytoepiphyton, phytoplankton and phytobenthos. The total primary production during the vegetation period was approximately forty times higher than the annual production of the fish. Currently, the share in the phytoplankton of large colonial cyanobacteria not consumed by zooplankton, the share of non-heterocystic species of cyanobacteria capable of heterotrophic feeding and the share of mixotrophic flagellates is increasing. Eutrophication of the reservoir is significantly stimulated by the development of macrophytes, and, presumably, the contribution of macrophytes to the total primary production of the reservoir will continue to increase
Influence of lead salts on some morphological and physiological parameters of filamentous cyanobacteria
Get PDFIn the conditions of a model laboratory experiment the influence of lead salts (an acetate and nitrate) on morphological and physiological parameters of filamentous cyanobacteria was studied. During the experiment we estimated features of formation of biomass, structure of trichomes, form and the size of cells, content of chlorophyll a, carotenoids and phycobiliproteins. It is noted that in the presence of lead acetate of up to 5 maximum allowable concentrations there is a formation of a biomass in the form of attached and free films, and presence of a nitrate form of lead at the same concentration promotes formation of filaments, fixed from one side. At the same time, the increase of concentration of both acetate, and nitrate forms of lead promotes formation of rarefied films of one layer multidirectional trichomes; to disintegration of trichomes on the fragments and separate cells united by an external mucilaginous envelope. Content of lead acetate in concentration of 15 times the maximum allowable concentration, and lead nitrate at 10 times the maximum allowable concentration leads to formation of abnormally long cells up to 10.0–10.5 µm long. It is established that lead acetate has a stimulating effect on formation of a biomass and synthesis of photosynthetic pigments. The biomass growth of up to 223.7% of the control was observed at concentration up to 15 times the maximum allowable concentration inclusive. The content of chlorophyll a grew by 30.6%, carotenoids – by 24.0% at one maximum allowable concentration. Lead nitrate stimulates a biomass gain much more weakly – up to 70.0% at 5 times the maximum allowable concentration and also has the expressed inhibiting effect on synthesis of photosynthetic pigments. Depression of concentration of chlorophyll a and carotenoids by 38.8% and 79.4% respectively was observed already at one maximum allowable concentration. The stimulating effect of lead acetate is noted on synthesis of phycocyanin (by 94.0%) and allophycocyanin (by 120.0%) in concentration up to 5 times the maximum allowable concentration; the stimulating effect of lead nitrate was observed on synthesis of phycocyanin (by 64.7%) in concentration up to 5 times the maximum allowable concentration and on synthesis of allophycocyanin (up to 140.0%) and on phycoerythrin (up to 228.0%) at concentration up to 10 times the maximum allowable concentration. Comparison of influence of various lead salts on filamentous cyanobacteria revealed a more expressed inhibiting effect of the nitrate form of lead in comparison with acetate
The effect of vehicle exhaust emissions on morphometric and physiological characteristics of Rhus typhina
Get PDFRhus typhina L. (Staghorn Sumac) is fast-growing woody species that reproduces by rhizomes and seeds. Because of its biological benefits, this deciduous member of the Anacardiaceae family has been introduced from its native habitats in the east of North America to urbanized landscapes of Ukraine. In this study we anаlyse changes in morphometric and physiological indicators of 12-year plants of this species in artificial phytocenoses near highways in Pavlograd, Ukraine. Experimental plots were placed at a distance from 25 to 130 meters from the road. The control group of plants was at a distance of 1500 m from the highways. We measured the length and thickness of the annual sprout, number of leaves on it, the content of chlorophyll in the leaves and accumulation of cadmium and lead in the leaf tissues. It was found that, compared to the plants in the relatively clean area, the greatest decreases in the length of the annual shoots of the trees in the plantations were for those which were at a distance of twenty five metres and forty meters from the traffic lanes of the highways. The thickness of the annual shoots of the trees in the plantations did not differ from plants in the clean zone. The number of leaves on a one-year annual sprout at a distance of twenty five meters and forty meters from the path of moving sources of pollution was significantly lower compared to control. We evaluated the impact of vehicle exhaust emissions on the assimilatory organs. We identified a negative effect of the anthropogenic pollutants on photosynthetic pigment content in leaves. The amount of chlorophyll a and chlorophyll b decreased with decreasing distance from the plantation to the road. Changes in the content of chlorophyll b had a clear pattern. The concentration of this pigment and the amount of chlorophyll a + b decreased compared with control in the 130 meter area. The amount of toxic heavy metals (lead and cadmium) in the tissues of the leaf was significantly higher than the control values on all plots. The strongest negative effects of phytotoxicants on susceptible plants occurred in plantations in the twenty-five-meter zone, which led to deterioration of the decorative quality of the plants
Structural comparative analysis of forest and steppe plant communities in the south of Kryvyi Rih region
Get PDFWe made a comparative analysis of the floristic structure of 11 various-aged (30–50-year-old) forest and four steppe communities in the south of Kryvyi Rih region. We ascertained that the forest communities have low specific richness (2–90 species), whereas steppe ones contain from 167 to 251 species. The ten families leading in the species number are: Asteraceae, Poaceae, Rosaceae, Fabaceae, Lamiaceae, Caryophyllaceae, Boraginaceae, Apiaceae, Brassicaceae and Polygonaceae. Specific representation of the steppe communities depends on the geomorphologic formation, grazing pressure, soil cover composition; respective order of families differs slightly: Asteraceae, Poaceae, Fabaceae, Rosaceae, Scrophulariaceae, Lamiaceae, Caryophyllaceae, Brassicaceae, Apiaceae, Boraginaceae. The core of the geographical structure of forest vegetation is the species with a palaearctic type of range (30.3–54.5%), and in the steppe, species with the Black Sea area group (15.6–24.0%). The second and the third most numerous in forest groups are groups of species of transitional areas (3.6–23.3%) and holarctic species (7.0–17.2%). In the steppe communities, almost the same proportions are formed by the species of the palaearctic group and the plants of group of transitional areas (15.8–23.1% and 18.3–21.7% respectively). We revealed that in the forest and steppe communities the most numerous group in the spectra is the biomorph of hemicryptophytes (25.6–42.4% and 45.8–47.0% respectively). According to the structure of the above-ground shoots, identical proportions are formed by rosetteless and semi-rosetted species (38.3–60.5% and 37.2–56.7% respectively) in the forest communities, and semi-rosetted species (47.4–49.1%) in the steppe ones; as for the type of structure of underground shoots in forest communities, species without special underground formations (33.3–65.1%) and caudex formations (18.6–36.4%) prevail, and, in the steppe communities – caudex species do (39.1–47.9%); xeromesophytes (33.3–100%), and mesoxerophytes (32.9–40.6%) dominate in the hygrospectra of forest and steppe communities respectively; in heliospectra, there is the predominance of heliophytes (62.3–97.1% and 50.8–67.5% respectively); in trophoscopes, the mesotrophs are prevalent (57.1–98.4% and 47.0–52.1% respectively). The ecological and coenotic spectrum of forest communities is characterized by the domination of synanthropophants (36.3–58.6%), and in steppe ones – steppants (51.8–55.0%). We revealed the similarity of the floristic composition of forest and steppe communities (6.8–39.4%), and the largest index is noted for the plot with a strict nature reserve regime (19.4–39.4%). In forest communities, this value is 15.6–66.7%, and it varies in different-aged plantations of the same species. The analysis shows that there are significant differences in the floristic and biomorphological composition of forest and steppe communities; it confirms the concept of O.L. Belgard on the environment transforming function of artificial steppe forests, changing the biotic circulation, which is inherent in the steppes
Influence of river water quality on homeostasis characteristics of cypriniform and perciform fish
Get PDFWithin an integrated ecosystem approach, it is preferable to evaluate the effects of pollution of surface waters through research on the organisms of fish. The aim of this study was to analyse the impact of a set of water quality indicators on the homeostasis of fish, in order to determine the response of a hydro-ecosystem to the impact of human activity. Fish samples were obtained from control catches in 16 control sites located in the rivers of Rivne Oblast which differ in intensity of anthropogenic load. The researchers observed that increased concentrations of phosphates and suspended substances, heavy metals, iron, fluorides and nitrogen compounds have violated the environmental state of the examined hydro-ecosystems. Parameters of the morphological homeostasis were assessed by the levels of the fluctuating asymmetry of the meristic signs of fish.The scientists recorded significant impairments (within IV points of body stability) in case of roach and bleak in the majority of the control sites. We carried out the analysis of cytogenetic parameters of fish homeostasis using a micronuclear test of blood erythrocytes.The investigation revealed a significant excess of spontaneous mutagenesis (1.1–1.7 times) in such species as roach, bleak and perch, and this is certainly a clear indicator of unfavourable ecological conditions of the water environment in seven areas of hydro-ecosystems. Given the results of the analysis, the authors found that different ecological groups of fish have their own complex and multifactorial processes of morphological and cytogenetic homeostasis formation. Furthermore, the regression dependences set out in the paper indicated the decisive impact of the oxygen regime of the water environment (COD, BOD5, О2), pollutants (Cu2+, Zn2+, Mn2+), and substances of biogenic group (NH4+, NO2–, PO4‑) upon fish homeostasis. differences in scope of homeostasis characteristics of different fish species were complemented by the differences in the composition of the regression equations. In particular, in case of species that had signs of homeostasis violation, the equation consisted of a greater number of members. The dependences for morphological and cytogenetic homeostasis of bleak and roach appeared to multifactorial. This finding suggests that these species are sensitive local indicators of the water environment both at early and late stages of ontogeny . Finally, as an outcome of the research we obtained prognostic forms of the relationship between water quality indicators and fish homeostasis that may form the basis of an environmental assessment method in which fish characteristics are used to assess the health of hydro-ecosystems.Within an integrated ecosystem approach, it is preferable to evaluate the effects of pollution of surface waters through research on the organisms of fish. The aim of this study was to analyse the impact of a set of water quality indicators on the homeostasis of fish, in order to determine the response of a hydro-ecosystem to the impact of human activity. Fish samples were obtained from control catches in 16 control sites located in the rivers of Rivne Oblast which differ in intensity of anthropogenic load. The researchers observed that increased concentrations of phosphates and suspended substances, heavy metals, iron, fluorides and nitrogen compounds have violated the environmental state of the examined hydro-ecosystems. Parameters of the morphological homeostasis were assessed by the levels of the fluctuating asymmetry of the meristic signs of fish.The scientists recorded significant impairments (within IV points of body stability) in case of roach and bleak in the majority of the control sites. We carried out the analysis of cytogenetic parameters of fish homeostasis using a micronuclear test of blood erythrocytes.The investigation revealed a significant excess of spontaneous mutagenesis (1.1–1.7 times) in such species as roach, bleak and perch, and this is certainly a clear indicator of unfavourable ecological conditions of the water environment in seven areas of hydro-ecosystems. Given the results of the analysis, the authors found that different ecological groups of fish have their own complex and multifactorial processes of morphological and cytogenetic homeostasis formation. Furthermore, the regression dependences set out in the paper indicated the decisive impact of the oxygen regime of the water environment (COD, BOD5, О2), pollutants (Cu2+, Zn2+, Mn2+), and substances of biogenic group (NH4+, NO2–, PO4‑) upon fish homeostasis. differences in scope of homeostasis characteristics of different fish species were complemented by the differences in the composition of the regression equations. In particular, in case of species that had signs of homeostasis violation, the equation consisted of a greater number of members. The dependences for morphological and cytogenetic homeostasis of bleak and roach appeared to multifactorial. This finding suggests that these species are sensitive local indicators of the water environment both at early and late stages of ontogeny . Finally, as an outcome of the research we obtained prognostic forms of the relationship between water quality indicators and fish homeostasis that may form the basis of an environmental assessment method in which fish characteristics are used to assess the health of hydro-ecosystems.Within an integrated ecosystem approach, it is preferable to evaluate the effects of pollution of surface waters through research on the organisms of fish. The aim of this study was to analyse the impact of a set of water quality indicators on the homeostasis of fish, in order to determine the response of a hydro-ecosystem to the impact of human activity. Fish samples were obtained from control catches in 16 control sites located in the rivers of Rivne Oblast which differ in intensity of anthropogenic load. The researchers observed that increased concentrations of phosphates and suspended substances, heavy metals, iron, fluorides and nitrogen compounds have violated the environmental state of the examined hydro-ecosystems. Parameters of the morphological homeostasis were assessed by the levels of the fluctuating asymmetry of the meristic signs of fish.The scientists recorded significant impairments (within IV points of body stability) in case of roach and bleak in the majority of the control sites. We carried out the analysis of cytogenetic parameters of fish homeostasis using a micronuclear test of blood erythrocytes.The investigation revealed a significant excess of spontaneous mutagenesis (1.1–1.7 times) in such species as roach, bleak and perch, and this is certainly a clear indicator of unfavourable ecological conditions of the water environment in seven areas of hydro-ecosystems. Given the results of the analysis, the authors found that different ecological groups of fish have their own complex and multifactorial processes of morphological and cytogenetic homeostasis formation. Furthermore, the regression dependences set out in the paper indicated the decisive impact of the oxygen regime of the water environment (COD, BOD5, О2), pollutants (Cu2+, Zn2+, Mn2+), and substances of biogenic group (NH4+, NO2–, PO4‑) upon fish homeostasis. differences in scope of homeostasis characteristics of different fish species were complemented by the differences in the composition of the regression equations. In particular, in case of species that had signs of homeostasis violation, the equation consisted of a greater number of members. The dependences for morphological and cytogenetic homeostasis of bleak and roach appeared to multifactorial. This finding suggests that these species are sensitive local indicators of the water environment both at early and late stages of ontogeny . Finally, as an outcome of the research we obtained prognostic forms of the relationship between water quality indicators and fish homeostasis that may form the basis of an environmental assessment method in which fish characteristics are used to assess the health of hydro-ecosystems
Physiological age of female blood-sucking midges (Diptera, Ceratopogonidae) in the south of Tyumen oblast
Get PDFDespite the fact the fact that biting midges (Diptera, Ceratopogonidae) are abundant blood-sucking insects in a number of areas of Siberia and the Far East, their biology in Russia and abroad is poorly studied. The objective of our research was physiological age of female midges in the subzone of southern taiga of Tyumen Oblast. Physiological age of female midges was determined using the method of V. P. Polovodova and T. S. Detinova, suggested for mosquitoes, modified for midges, in relation to the number of the yellow bodies – enlarged ovarioles. The conducted studies focused on physiological age of females of three species of midges of the subgenus Avaritia (Culicoides punctatus, C. fascipennis, C. grisescens), which occur in the forest zone of the southern taiga subzone. The species are abundant blood-sucking insects. Mostly, they complete one gonotrophic cycle, but by the end of the season, the number of females which had laid eggs twice reached 20–30%. Part (10–22%) of the female population does not succeed in completing even a single gonotrophic cucle. In spite of colder weather in the end of summer, a rejuvenation of the population was observed, which occured due to death of physiologically old females. Comparison of changes in number and age composition of females allows us to state that the first two species have two, and the third – one generation during a season. Determination of physiological age of females or the number of gonotrophic cycles they complete, and therefore, the extent of their biting, is a subject of not only theoretical but also practical interest for assessing the epidemiological situation in the areas where midges are vectors of a number of infectious and invasive diseases, such as tularemia, onchocerciasis, bluetongue virus or febris catarrhalis ovium, and Schmallenberg virus. This indicates the relevance of studying density of population vectors of infections. In the Russian Federation, such research unfortunately has only been conducted within the scope of narrow studies, and only in certain regions
Diversity and structure of avian communities in extensive lowland pine forests in relation to the distance from the forest edge
Get PDFMost studies on edge effect are related to the forest-field edge, i.e. to the ecotone. However, there is a lack of studies attempting to investigate the effect of the distance from the forest/field edge on the avian communities in large continuous forests. The purpose of this study was to investigate this issue. The study area comprised a continuous coniferous forest, the so called Niemodlin Forest, situated in Opole Silesia, SW Poland. The line transect method has been employed in this study. In total, 54 breeding bird species were recorded. On particular 0.5 km section, the numbers varied from 34 to 48. Both the number of species and number of breeding pairs only slightly decreased with the distance from the forest/field edge. Overall, the differences between the mean densities of breeding species on 10 sections were not statistically significant. The Chaffinch Fringilla coelebs was by far the most numerous bird species, recorded as eudominant in 164 out of 165 sections. The Chiffchaff Phylloscopus collybita, Willow Warbler Phyloscopus trochilus and Blackap Sylvia atricapilla were dominants in all 10 sections, while the Blackbird Turdus merula dominated in nine (90%) and the Robin Erithacus rubecula in eight (80%) sections. The communal dominance slightly increased, but the number of dominant species and Pielou’s Evenness Index remained stable with the increase of the distance from the forest/field edge. While Shannon’s Diversity Index remained constant, Simpson’s Diversity Index decreased markedly with the increase in distance from the forest/field edge. The proportion of long-distance migrants slightly decreased, while that of short-distance migrants and residents remained constant with the increase in the distance from the forest/field edge. Strikingly, no such changes in the proportion of all feeding guilds were shown. More than half of all breeding bird species show a negative correlation between population density and the distance from the forest/field edge. The dominance of some species decreased with the increase of the distance from the forest/field edge: Hawfinch Coccothraustes coccothraustes, Starling Sturnus vulgaris, Blue Tit Parusa caeruleus, Raven Corvus corax, Wren Troglodytes troglodytes, Wood Pigeon Columba palumbus, and Wood Lark Lullula arborea. With the exception of the Yellowhammer Emberiza citrinella, the clearcuts in this study, not only failed to increase, but most probably caused a decrease in the number of both species and individuals. It is because clearing not only creates edges, but also causes loss of forest habitat and often results in forest fragmentation. Edge and area effect may in fact interact, in such way that the edge effect may drive out the area effect, causing the increase
Radial increment dynamics in Pinus sylvestris stands within the Northern Steppe of Ukraine
Get PDFThe parameters of periodic increment (5-years) and peculiarities of its change depending on age, diameter, height and volume of trunk of Scots pine are determined. The influence of climate conditions (air temperature and precipitation) on the dynamics of radial increment change of Scots pine trees are established. The results of experimental studies, obtained from 20 temporary sample plots of pine stands within the Northern Steppe of Ukraine are presented. We conducted an estimate of radial increment of Scots pine trunks as a basis for development of normative and information support for assessment of biotic productivity of this category of forest. All selected sample trees had different age and biometric parameters. The age of sample trees ranged from 9 to 90 years; diameter at breast height – from 4.0 to 41.7 cm; height – from 4.2 to 30.0 m, trunk volume – from 0.002 to 1.748 m3. It is found that the radial increment of pine stem was significantly dependent on tree age. The highest values of radial increment of Scots pine trees were observed for trees aged up to 20 years. With increasing age, radial increment had a decreasing trend, including 90-year old trees. Regression models of the dependence of radial increment of pine trees on the age and diameter are presented. In the article, the dependence of the values of radial increment of sample trees from types of forest are demonstrated. The highest values of Scots pine radial increment was observed in sugruds and gruds, which were presented in tree samples of 20 years. Comparative analysis of radial increment change in the trees of one age category, which grew in different conditions, was conducted. The older trees had the maximum increment in the conditions of dry sugrud, and the minimum increment in conditions of fresh subor. Also in this article we used generalized chronology of Scots pine radial increment reflecting regional variability of growth in pine trees. The results supplemented the research obtained earlier with new data on the dependence of the pine radial growth rate on forest-biometric parameters. These experimental data, their graph-analytical evaluation yielded an information basis for modeling the radial increment of pine trees, created on the basis of dependence of this parameter on biometric indexes – age and diameter at breast height
Steppe rodents at the edge of their range: A case study of Spalax microphthalmus in the north of Ukraine
Get PDFBased on results obtained during 2000–2018 by field research, polls of colleagues, and OSINT analysis, features of distribution of the greater mole rat Spalax microphthalmus in the eastern forest steppe of Ukraine were considered. The studied part of the species’ range is unique and represents the northern range edge of the entire Spalacidae family and of European steppe faunal assemblages in general. In total, data on 146 record localities were amassed, including 13 localities in the fragmented and 133 in the continuous part of the range. The offshoots of the Central Russian Upland in the valley of the Psel river (east of Sumy Oblast) are the sites with the highest density of settlements, while the species’ type biotopes are steppe balka slopes. The abundance of the greater mole rat decreased from the east to the west, and its colonies are the most fragmented along the Dnipro River. The species occurs in steppe and meadow habitats of an area of at least 20–50 ha. Analysis of the current and former distribution of the greater mole rat revealed that the species range contracts from the west; earlier it was a common species in different regions of the Middle Dnipro Area (including Kyiv city), but the current range edge runs along the line connecting Buryn – Nedryhailiv – Lokhvytsia – Myrhorod – Hadiach – Zinkiv – Zaliznychne. Isolated settlements exist in adjacent territories, particularly in Ichnia Raion of Chernihiv Oblast, and Lubny, Khorol, and Kobeliaky Raions of Poltava Oblast. The study showed that the species’ range contracted by two times to 35,000 km2 for the last 100 years, which includes only 430,000 ha of suitable habitats (15% of the range), allowing the existence here of 86,000–215,000 individuals. In fact, the species remained only in habitats that have been minimally affected by arable farming and other forms of active agricultural use. Besides, the species shows a clear confinement to habitats located near human settlements such as untilled lands, pastures with moderate grazing, waste and neglected lands, which constitute a separate group of transformed and semi-natural habitats. Formally, this allows the greater mole rat to be considered as a synanthropic species, because its inhabited biotopes, beside the zone of offshoots of the Central Russian Upland, have remained only near villages and along roads. The species also has an important biocoenotic role due to its burrowing activity and as prey of predatory birds (e.g., of the long-legged buzzard and Eurasian eagle owl) and mammals. The feeding period of the offspring of these predators generally coincides with the aboveground activity of mole rats, which lasts during May–July with a peak in June. Aboveground activity is mainly related to the resettlement of mole rats to new sites and dispersal of the young, due to which they became victims of predators