Contents of Proceedings of the Zoological Institute

Trophic relationships reflect the peculiarities of the functioning of communities of aquatic organisms and analysis of their structure and dynamics can be used to improve fisheries management and assess the state of marine ecosystems. Populations at the margins of the species' range have particular adaptations, including feeding habits, to extreme conditions, which makes them a convenient model object for studying the possible consequences of ecosystem changes under the influence of global factors. The cod Gadus morhua marisalbi Derjugin, 1920 permanently inhabits the coastal waters of the subarctic White Sea, located at the northeastern margin of the geographic range of the Atlantic cod G. morhua Linnaeus, 1758. This coastal cod population strongly depends on the local environmental conditions and available food resources during the summer feeding period. In addition to the main food organisms (fish, polychaetes, crustaceans), the eggs of fish spawning in shallow coastal areas in summer are also important in the diet of cod at this time. According to published data, fish eggs found in significant quantities and most often in the stomachs of cod belonged to threespine stickleback and lumpfish, but this has not been confirmed by any experimental research. Besides, the possible presence of herring eggs in the diet of cod remains unproven due to the difficulties of its visual identification. In this work, we used molecular genetic methods for species identification of fish eggs found in cod stomachs. At the first stage, the species identification of DNA isolated from eggs was done using two sets of species-specific primers: the first which we designed for the mitochondrial COI gene of stickleback, cod, and herring, and the second, published for a microsatellite locus of herring. At the second stage, the species identity of DNA extracted from fish eggs was checked using DNA barcoding. The results showed that cod stomachs contained herring and stickleback eggs, and in a number of cases we found the co-occurrence of eggs of these species. Of the 29 DNA preparations studied, fourteen were successfully amplified with microsatellite primers for herring, and thirteen amplified with primers for stickleback. Interannual differences in the occurrence of herring eggs in samples were insignificant, while the frequency of occurrence of stickleback eggs in 2018 was higher than in 2017. Our analysis did not reveal significant intra-annual differences between the observed and theoretically expected number of cases of simultaneous occurrences of herring and stickleback eggs. The high frequency of occurrence of herring and stickleback eggs in cod stomachs revealed in this study indicates the importance of these components in the diet of cod and provides new knowledge on the trophic role of cod as a key species in the White Sea ecosystem. Analysis of available data on the spatial and temporal diet patterns of coastal White Sea cod shows that fish eggs can significantly contribute to the total amount of food consumed by this species during the summer.

In early June and July 2018 and 2019, during the reproduction period, we captured and equipped with satellite transmitters (5.3 g PinPoint GPS ARGOS 120) four males of the common cuckoo Cuculus canorus canorus (Linnaeus, 1758) in the vicinity of the city of Abakan in Khakassia, Southern Siberia. In one male, it was possible to track the route of autumn migration up to the border of the Democratic Republic of the Congo with Zambia (10 819 km), in another male to Western Iran. The routes of the other two birds were interrupted for unknown reasons in the Pavlodar region of Kazakhstan and in the Novosibirsk region. Satellite data confirmed our assumption that the cuckoos breeding in the territory of Southern Siberia migrate in autumn to the southwest via Kazakhstan, Central Asian countries (Uzbekistan, Turkmenistan), Iran, and Saudi Arabia to the southern part of Africa.

The first species of the genus Plaxiphora from the Paleocene of Ukraine is described. The characteristic features of Plaxiphora luzanovkae sp. nov. are the strongly increasing size of tegmentum granules toward the edge of the valve, a large number of micraesthetes on these granules, and a random arrangement of the granules. Since the predominant occurrence of the species of the genus is in the Southern Hemisphere, with almost half found in New Zealand and Australia, it is likely that the first species of the genus originated during the final disintegration of Gondwana.

During April 2022, offshore dredging for a storm damage beach renourishment project placed large quantities of Upper Cretaceous (upper Maastrichtian) Peedee Formation sediment onto the shores of Holden Beach in Brunswick County, North Carolina, USA. The Cretaceous sediment is highly fossiliferous and has yielded a rich and diversified assemblage of fossils from mosasaurid reptiles. New fossil material, namely isolated teeth, consists of several dental morphologies from the mosasaur subfamilies Halisaurinae and Mosasaurinae. Five species are recognized: Halisaurus sp., Mosasaurus cf. beaugei Arambourg, 1952, Mosasaurus cf. hoffmannii Mantell, 1829, Prognathodon cf. solvayi Dollo, 1889 and Prognathodontini indet. In this assemblage, prognathodontins predominate, being the most abundant marine reptile find, with all other species being comparatively rare. The mosasaur assemblage of North Carolina shows close affinity with the phosphates of Morocco, containing species typical of both the northern and southern margins of the Mediterranean Tethys. These new discoveries improve our knowledge of the biodiversity of mosasaur fauna from the late Maastrichtian of North Carolina and add to the known paleobiogeographical distribution of these taxa. The material described within was collected courtesy of the efforts of amateur fossil hunters and seasonal tourists combing Holden Beach for fossilized remains.

The paper examines the population dynamics of common species of small mammals in southern Karelia (Sorex araneus L., 1758 and Myodes glareolus Scherber, 1780) based on the results of long-term stationary studies. Small mammals in the study area were captured in the summer and autumn of the period 1966–2014 using standard snap trap lines. At each trapping session, all habitat types were sampled. The dominant species in the small mammal population, like anywhere in Eastern Fennoscandia, were Sorex araneus and Myodes glareolus. Both dominant species live here at the edge of their ranges. As a result of the data analysis of the long-term abundance of these small mammal species, the presence of two time periods (1966–1990 and 1991–2014) was established, differing for each of the species under consideration in the nature of changes in abundance. For both the common shrew and the bank vole in the second period, a change in the nature of population cyclicity was noted, expressed by a change from a tendency toward 3–4-year cycles to chaotic fluctuations. Also, a decrease in the amplitude of population fluctuations was observed for both species. For the bank vole, there was also a decrease in the population level. A discrepancy was noted in the previously existing correlation of the long-term abundance of the background species. The probable reason for such changes is the warming of the climate observed in the north of Eurasia in the 21st century. For peripheral populations of small mammals, endogenous factors regulating numbers come to the fore. This influence is indirect, as warmer winters and springs create more favorable living conditions for animals.

All available data on Auchenorrhyncha from Iraq are summarized, listing 11 families and 128 species in 94 genera including the subfamily Ulopinae Le Peletier et Audinet-Serville, 1825, the tribe Vartini Zahniser et Dietrich, 2013, the subtribes Adelungiina Baker, 1915, and Paradorydiina Evans, 1936 and the genera Cofana Melichar, 1926, Utecha Emeljanov, 1996, Varta Distant, 1908, Balcanocerus Maldonado-Capriles, 1971, Hespericerus Gnezdilov, 1999, Platyproctus Lindberg, 1925, Achrus Lindberg, 1925, Dryodurgades Zachvatkin, 1946, Paradorydium Kirkaldy, 1901, Artianus Ribaut, 1942, Tamaricades Emeljanov, 1962, and Masiripius Dlabola, 1981 of the family Cicadellidae, with 18 species, and Trypetimorpha occidentalis Huang et Bourgoin, 1993 of the family Tropiduchidae and Ommatidiotus iranicus Horváth, 1905 and Chirodisca astyages (Dlabola, 1982) of the family Caliscelidae are recorded for the first time from Iraq. Zubara lycii Al-Ne’amy et Linnavuori, 1982 is redescribed based on the specimens from Diyala Province. Zygina hussaini Ghauri, 1964 is placed in synonymy under Arboridia kermanshah Dlabola, 1963. Dictyophara iracina Dlabola, 1989 is transferred to the genus Raivuna Fennah, 1978, with a new combination proposed – Raivuna iracina (Dlabola, 1989), comb. n. The lectotype is designated for Dorydium breviceps Melichar, 1902 [currently Paradorydium breviceps (Melichar, 1902)] to stabilize the nomenclature in the studied group according to the International Code of Zoological Nomenclature.

The article describes fossil material of a leatherback sea turtle Dermochelyidae indet. from the Bayurbas and Sandy localities of the Shorym Formation (Bartonian, Middle Eocene) of the Mangyshlak Peninsula, Kazakhstan. The material is represented by cranial remains of one individual (Bayurbas) and an epithecal plate of the shell (Sandy). Dermochelyidae indet. from the Shorym Formation differ from all known dermochelyids in the morphology of the skull roof and the dentary. Based on the morphology of the epithecal plate, it is most similar to the representatives of the genera Cosmochelys Andrews, 1919 and Egyptemys Wood et al., 1996, whose skulls are unknown. The described cranial remains partially fill a large temporal gap (about 13.9 Ma) in our knowledge of the skull morphology of dermochelyids, between the oldest Ypresian species and the Rupelian Cardiochelys rupeliensis (Van Beneden, 1883). In addition, these are the first cranial remains of dermochelyids described from northern Eurasia (territory of the former Soviet Union).

The species composition of the mid-Early Pleistocene fauna in northwestern Azerbaijan has been elucidated through the analysis of fossil material recovered from the Palan-Tyukan site. This research also included a review of the relevant literature. The paleontological material has been fossilized to a similar extent, indicating similar burial conditions. Animal bones at the site were accumulated during a single sedimentation cycle in sediments of what was once a shallow, heavily silted body of water with slow-flowing or standing water. We have identified 16 species of large mammals, whose presence has allowed us to determine the time period in which this faunal complex existed, as well as the characteristics of the natural environment at the time of its formation. The order Carnivora is represented by 10 individuals, the order Proboscidea by 2 individuals, the order Perissodactyla by 3 individuals, and the order Artiodactyla by 18 individuals. The Palan-Tyukan paleo-landscape can be described as a mosaic of different environments. Flat riverine areas with dense vegetation gradually transitioned into the hilly steppe with mixed vegetation of varying densities. Our reconstruction of the paleogeographic environment indicates that large mammals of Palan-Tyukan lived there under conditions of a relatively humid subtropical climate. The Palan-Tyukan faunal complex belongs to the Mediterranean palaeobiogeographical subregion, biozone MNQ18, at the beginning of the Late Villafranchian period, and falls within the time interval from 1.93 to 1.77 million years ago.

The results of studying 562 bone remains of Crocuta spelaea (Goldfuss, 1823) from 12 cave sites in Khakassia and Altai and 4 alluvial sites in the upper Ob River are presented. In the Fanatics cave in Khakassia, 3 almost complete skeletons of cave hyenas and one partially preserved were found. In this trap cave, 37–42 thousand years ago, hyenas died falling into a deep karst well. Morphometric analysis of the skulls and bones of the postcranial skeleton showed that the cave hyenas of the Late Pleistocene of southern Western Siberia did not differ in body size from the hyenas of Western Europe. In the alluvial localities of the Upper Ob region, the remains of C. spelaea are extremely rare, averaging 0.07% of the number of megafauna remains, which is several times less than that of the cave lion. In the Altai and Khakassia mountains, the relative abundance of cave hyenas may not have been inferior to that of Panthera leo spelaea (Goldfuss, 1810). During the glaciation periods, when cold and arid mountain-steppe landscapes dominated here, inhabited by diverse and numerous megafauna, the abundance of C. spelaea was the highest. During the interglacial period, against the background of widespread forest vegetation, the abundance of herd-hoofed animals decreased, which led to a several-fold decrease in the number of cave hyena populations. The most recent remains of C. spelaea from the Chik River are dated to the age of 33.4 thousand years ago.

The voles Microtus kermanensis Roguin, 1988 and M. mystacinus De Filippi, 1865 are representatives of the “mystacinus” group in the subgenus Microtus (2n = 54). A three-year study of reproduction of these species was conducted in the Laboratory of Theriology of the Zoological Institute RAS. The laboratory populations of voles were created from animals caught in Iran. In this study, 38 pairs of M. kermanensis and 18 pairs of M. mystacinus were under observation. For the study of postembryonic ontogenesis, 39 litters (166 pups) of M. kermanensis voles and 14 litters (51 pups) of M. mystacinus were examined. For comparison, 10 litters (47 pups) of M. arvalis Pallas, 1978 (form “arvalis” from the Vladimir region) were used. The breeding of animals continued all year round. The average number of pups per litter was 4.3 in M. kermanensis, 3.6 in M. mystacinus, and 4.7 in M. arvalis; the sex ratio in all species was close to 1:1. High mortality was noted in the larger M. kermanensis (28.3%), with lower rates in M. mystacinus (15.7%) and M. arvalis (17.0%). In general, the development of pups of all three species during the first 12 days of life is fast. Among the distinctive features, the early separation of the auricles in M. mystacinus is of note. The large M. kermanensis is characterized by earlier divergence of the fingers on the fore and hind limbs, which ends by day 10 (in M. mystacinus and M. arvalis by day 12). Also, in M. kermanensis the timing of incisor eruption is extended; the lower incisors begin to erupt on day 3 and appear by day 9 in 100% of the pups (by day 7 in the other two species). The upper incisors begin to erupt from day 4, and 100% of the pups have them by day 10 (in M. mystacinus and M. arvalis, they completely erupt on day 8). In all three species, their eyes start opening at 9 days and open completely by day 12; such uniformity can serve as confirmation of the phylogenetic proximity of these species. All three species are characterized by the avoidance of incest.

Long-term changes in species composition, production indicators, and structure of polychaete communities for the period of 2003 and 2019 in the Russian part of the Varanger fjord (Barents Sea) were shown. The connection of such changes with climate factors and the influence of the red king crab are considered. The changes in species composition, structure, and production characteristics of polychaetes in the Russian part of the Varanger fjord (Barents Sea) in 2003 and 2019 are shown. The linkage between these changes and the climatic factor, as well as the influence of the introduced red king crab Paralithodes camtschaticus (Tilesius, 1815), is discussed. The results demonstrate an increase in the quantitative characteristics of polychaete Spiochaetopterus typicus M. Sars, 1856, indicating a decrease in pressure from the king crab on bottom communities. The biodiversity indices indicate the absence of negative changes in the settlements of polychaetes in the Varanger fjord during the studied period.

The paper presents the results of using neural networks of pixel-by-pixel image classification to decipher multichannel space images obtained by the Landsat 8 satellite. Natural habitats were identified based on differences in phytocenotic characteristics of land areas. The level of use of areas by elk was determined by the occurrence of elk presence indicators, which were the density of winter excrement piles (in spring) and the abundance of winged forms of the monoxenous ectoparasite of elk, Lipoptena cervi (Linnaeus, 1758), as measured by the number of individuals attacking the census taker (in the summer-autumn period). The material that forms the basis for deciphering was obtained by the route census method in different areas of the Leningrad Province. High values of the measured parameters were recorded in reforestation areas, in wet pine and birch forests, in aspen forests, on the edges of raised bogs and in overgrown fields – typical elk winter feeding habitats. Based on the data on the maximum values of the measured parameters, a positive correlation was established for the first time between the abundance of winged forms of L. cervi and the physiological activity of the host (the density of the piles of “winter” excrement). The paper also provides a valid reference to the material of schematic maps developed for a part of the territory of the Leningrad Province and Saint Petersburg. The scheme of the use of areas by elk is compiled on the basis of the relative index calculated from the measured parameters of the survey. Field observation areas and territories close to them were most reliably identified (90–95% accuracy). For areas not covered by field observations, the paper provides comments on the main inaccuracies of the schemes and the reasons for the identified discrepancies, based on an analysis of literary sources devoted to similar research topics. The results of the study indicate that the frequency of attacks of winged forms of L. cervi can be used as an additional criterion for assessing the stationary preferences of elk in the winter period using information on the period of active flight, and the decoding method mentioned in the paper can be used in limited areas of specific territories, including reserves, areas of hunting farms and district forestries.

Corrigendum. An error was made in the title of the article, which incorrectly included a reference to "2023". The correct title of the article is: "Application of an artificial neural network for decoding Earth remote sensing data to identify natural habitats used by the European moose Alces alces (Linnaeus, 1758) during the autumn-winter period". For citation purposes, please use the original title as published in the journal. We apologize for this error.

Our work is dedicated to the comparison of the quantitative development of meiobenthos during the vegetative season and in winter in the dimictic subpolar Lake Krivoe (Karelia). The winter meiobenthos turned out to be significantly poorer in species composition than the meiobenthos of the vegetative season (13 and 29 species, respectively). Of the 8 meiobenthic groups typical for the lake, Ostracoda and Cladocera were completely absent in winter. An analysis of the proportions of the dominant meiobenthos groups showed that the studied lake fits into the group of typical lakes in the North-West of Russia, and does not belong to the group of polar lakes, as would be expected based on its geographical coordinates. The peculiarity of Lake Krivoe that makes it unique among subpolar lakes is the high biomass in the profundal in winter – 0.14 g/m², which does not significantly differ from that in the vegetative season – 0.2 g/m². In the littoral and sublittoral in winter, compared with the vegetative season, there is a significant decrease in meiobenthos biomass from 0.47 g/m² to 0.03 g/m² and from 0.05 g/m² to 0.001 g/m², respectively. In winter, the largest biomass of meiobenthos is provided by the profundal of the lake – 71.5% of the total biomass of meiobenthos, littoral – 27.25%, and sublittoral zone – 1.2%. In the vegetative season, the opposite picture is observed: in the littoral zone of the lake, meiobenthos makes up 71.5% of the total meiobenthos biomass, in the sublittoral zone – 9.70%, and 18.78% in the profundal zone. The biomass of the winter meiobenthos significantly positively correlates with the meiobenthos biomass in September, r = 0.82 (p < 0.001), and with that in May of the next year, r = 0.56 (p < 0.03). Correlations between meiobenthos biomasses in various months of the vegetative season were non-significant.

The article describes a fossil pan-cheloniid Protrachyaspis shorymensis gen. et sp. nov. from the Karakeshi, Kert, Kuyulus, and Monata localities of the Shorym Formation (Bartonian, middle Eocene), as well as unknown localities of the Mangyshlak Peninsula, Kazakhstan. In addition, the shell bones of small pan-cheloniids from the Kuyulus and Tuzbair localities of the Shorym Formation with some traits of P. shorymensis are described, which probably represent remains of juvenile specimens of this species. The new taxon is characterized by a number of features rarely found in pan-cheloniids, including serrated dentaries, distally displaced lateral process of the humerus, and deeply sculptured external carapace surface. These features indicate a likely herbivorous diet and pelagic lifestyle of the new pan-cheloniid. According to the results of the cladistic analysis, P. shorymensis is sister to the Neogene species Trachyaspis lardyi Meyer, 1843, from which it differs in the absence of ridges on the carapace in adult individuals, the configuration of the scutes on the parietal bone, and the structure of the plastron. The stratigraphic gap between the appearance of P. shorymensis and its sister T. lardyi suggests a long ghost lineage of members of this clade throughout the Bartonian – Aquitanian (ca. 20.7 million years) preceding the appearance of T. lardyi. In most trees, the P. shorymensis + T. lardyi clade is located within the Chelonini clade, which, taking into account the middle Eocene age of P. shorymensis, indicates the early divergence of crown cheloniids, previously established based on molecular data. The new taxon is similar to the fragmentary remains of pan-cheloniids with a sculptured external surface of the shell, previously described from four localities of the upper part of the Buchak and lower part of Kiev formations in the south of European Russia and Ukraine, which makes it possible to determine these materials as cf. Protrachyaspis sp., and probably extends the appearance of the P. shorymensis + T. lardyi clade back to the middle Lutetian.

Some publications report that passerine birds, compared with geese and waders, show much less annual faithfulness to migration routes and stopover sites, and that faithfulness to them decreases with increasing length of the migration path. The analysis of numerous recaptures of ringed birds in the Curonian Spit (Eastern Baltic) led to the opposite conclusions. The calculations were carried out on thousands of recaptures obtained over 30 years (1957–1986) from two of the most numerous species, chaffinch Fringilla coelebs Linnaeus, 1758 (Fringillidae) and willow warbler Phylloscopus trochilus (Linnaeus, 1758) (Phylloscopidae). It turned out that a significant part of the migratory populations (34–41% of recaptured birds) retains the same migration path and approximately the same migration timing in other years after ringing. Assumptions about the dependence of the degree of fidelity to migration routes on their length have not been confirmed, since the fidelity indicators of willow warbler, which has a much longer route than chaffinch, were even higher than those of the chaffinch. The data on the individual life longevity of the recaptured migrants (up to 9 years in the chaffinch and up to 4 years in the willow warbler) confirm the fidelity to the same migration path throughout the life of the studied birds.

A new material on the Indo-Malayan genera Peracca Griffini, 1897 and Oxylakis Redtenbacher, 1891 are examined. The feminine gender for the names of these genera as well as for some other but derivative generic and subgeneric names (generic names Amblylakis Redtenbacher, 1891, Odontolakis Redtenbacher, 1891, Paroxylakis Ingrisch, 1998, Bispinolakis Ingrisch, 1998, Depressacca Ingrisch, 1998 and Viriacca Ingrisch, 1998; subgeneric names Ocellakis Gorochov, 2013, Spinolakis subgen. nov., Sumatracca Gorochov, 2013 and Robustacca Ingrisch, 2020) is more definitely designed, and the necessary corrections of some species names are made. The composition of the genus Peracca is briefly discussed, and P. (Robustacca) setosa Ingrisch, 1998, comb. nov. is transferred from the subgenus Odontoconus Fritze et Carl, 1908 to the subgenus Robustacca. The subgeneric composition of the genus Oxylakis is expanded to four subgenera: Oxylakis s. str., Indolakis Gorochov, 2013, Ocellakis Gorochov, 2013 and Spinolakis subgen. nov. The key for subgenera of the genus Oxylakis is given. The following new species and subspecies are described and illustrated: Peracca (Peracca) simplex sp. nov. from Aceh Province (Sumatra) of Indonesia, Oxylakis (Spinolakis) spinosa sp. nov. from Sabah State (Borneo) of Malaysia and O. (Oxylakis) singaporensis aceh subsp. nov. from Aceh Province (Sumatra) of Indonesia.

The question of the modern and past distribution of Siberian zokor Myospalax myospalax (Laxmann, 1773) continues to be an unresolved puzzle. This Western Siberian endemic species belongs to the family Myospalacidae, a group of subterranean rodents. The distribution of M. myospalax went through dramatic changes due to mass hunting in the first half of the 20th century and later development of agriculture. Because of this, data from various studies executed in different years do not always match, making it difficult to determine the natural limiting factors in the distribution of Siberian zokors. In turn, paleontological data from different regions are fragmentary and have not been summarized in a single study. We aimed to review the past and modern distribution of M. myospalax and examine its relationship with environmental factors such as climate and soils distribution. We hypothesized that this species may be a good indicator of past environmental conditions because of its special habitat characteristics. We gathered and revised published data to reconstruct the distribution before the anthropogenic influence of the 20th century and during the Pleistocene and Holocene epochs. The modern preanthropogenic range was compared with the distribution of soil complexes and provinces. We also examined M. myospalax molars from Late Pleistocene – Holocene localities and compared them with the modern population. The Siberian zokor distribution data provided herein will be useful for researchers from other regions who use fragmentary or doubtful data on the topic. We also identified climatic and soil parameters of M. myospalax habitat. These parameters can be used to reconstruct past environmental conditions from paleontological findings of the Siberian zokor.

Anatomical-morphological features of the postcranial skeleton of nine taxa of the rock lizards of the genus Darevskia Arribas, 1999 belonging to the Darevskia (caucasica) and Darevskia (saxicola) complexes were studied for the first time on representative samples. Specimens with the rib formula 3+1 were found in both complexes (previously, only two variants were known for the genus Darevskia 3+2 and 3+3). Differences between supraspecific groups and their members were described with the use of type specimens or topotypes of each taxon. The studied complexes are differentiated by the range of variability of presacral vertebrae (in the D. (caucasica) their minimum number is 26, in the D. (saxicola) – 27), the number of the posterior presacral vertebrae with ribs (the average value of this trait in the D. (caucasica) is less than 6, in D. (saxicola) – more than 6). B-type of the tail vertebrae in 5 times more common in the D. (saxicola) than in the D. (caucasica). In turn, the latter group is characterized by a larger share of individuals with ossified ribs at the third cervical vertebra and a greater variability of the sternal-xiphisternal costal (rib) formula. Skeletal morphology of D. alpina indicates its greater similarity with representatives of the D. (caucasica) complex. A certain originality of D. c. vedenica was recorded. The study of D. saxicola specimens from the zone of sympatry with D. c. caucasica (Chegem Gorge) did not reveal their similarity with the latter, except for the presence of two variants of the sternal-xiphisternal formula. Cryptic forms within D. lindholmi differ at least in two traits: the minimum number of posterior presacral vertebrae with short ribs and the presence of individuals with caudal vertebrae of B-type.

A comparative analysis of juvenile anadromous and freshwater (stream) forms of the Black Sea brown trout Salmo trutta labrax Pallas, 1814 was conducted using 10 meristic and 62 morphometric characters of cranial bones. This analysis included the counts of teeth and pores in the bones, as well as measuring of their shape characters. As a basis for comparison, data on juvenile anadromous and freshwater Atlantic salmon Salmo salar Linnaeus, 1758 were used. The osteological differences between ecological forms were more pronounced in the brown trout than in the Atlantic salmon. In the brown trout, a greater number of meristic characters differentiated the forms compared to the salmon. However, for morphometric characters, the reverse pattern was observed. The freshwater forms exhibited characteristics intermediate to the anadromous forms of the two species, being more similar to the anadromous form of their species than to each other. Juvenile anadromous Black Sea trout typically had the fewest teeth, while juvenile Atlantic salmon had the most, with freshwater forms showing intermediate values. The most significant differences in the shape of cranial bones were also observed between the juvenile anadromous forms of two species. The characteristics pertaining to the number of pores in cranial bones did not reveal clear patterns when comparing the samples. Among the studied bones and characteristics, those showing the most significant differences between Black Sea trout and Atlantic salmon were identified, and species-specific features were noted. The results obtained show that juveniles of different ecological forms within the same species of the genus Salmo exhibit statistically significant osteological differences, suggesting a high genetic determination of these traits and the influence of selection within river systems on the divergence between freshwater and anadromous forms. Despite this, the variability in all studied characteristics indicates plasticity, resulting in the differences between the species and ecological forms within the genus Salmo typically not reaching the threshold for subspecies differentiation. These results align with previous studies on adult individuals and indicate that the freshwater form of the Atlantic salmon displays osteological characteristic of a more ancestral species, namely the brown trout.

The current state of macrozoobenthos of six low-mountain lakes of the Russian Altai was studied in different hydrological seasons (May, July, September) 2022: Aya (Aiskoe), Beloe, Kireevo, Kolyvanskoe, Koksha, and Svetloe. The aim of the article is to study the factors of formation of benthic invertebrate communities of foothill lakes of the Russian Altai. In total 156 species from 9 classes of invertebrates were identified in the zoobenthos of the studied lakes, the highest percentage of occurrence was recorded for chironomids and oligochaetes. According to the taxonomic composition of macrozoobenthos, most of the studied lakes of the Russian Altai (Aya, Beloe, Kireevo and Kolyvanskoe) were close to flatland lakes. Two lakes (Koksha and Svetloe) combined characteristics of both flatland and highland lakes. The abundance and biomass of zoobenthos in lakes Aya and Kireevo corresponded to the oligotrophic level, in lakes Beloe and Kolyvanskoe to the mesotrophic level, and in lakes Koksha and Svetloye to the eutrophic level. The structural characteristics of macroinvertebrates are indicators of the state of lake ecosystems. Therefore, in order to maintain the health of lake ecosystems, it is important to determine the limiting factors for macroinvertebrate community composition and structure. The influence of environmental factors on the composition and structure of macrozoobenthos of foothill lakes of the Russian Altai was studied. The relationship of 10 main indicators of zoobenthos structure with 30 hydro physical and hydrochemical indicators was analyzed. Using principal component analysis, multiple regression method, correlation and canonical analyses, it was revealed that the greatest influence on the development of benthic invertebrate communities in the studied lakes of the Russian Altai was exerted by nutrients, permanganate oxidability and soil character and water temperature.

This paper presents data on the distribution of the black grouse Lyrurus tetrix (L., 1758), capercaillie Tetrao urogallus (L., 1758), and hazel grouse Tetrastes bonasia (L., 1758) in the Nenets Autonomous Area (the northeast of the European Russian Federation). The study has revealed trends indicating an expansion of the distribution range of these species to the north. According to our observations, black grouse, capercaillie, and hazel grouse in the Malozemelskaya Tundra are located further north than in the published data – about 40 km for black grouse, 20 km for capercaillie, and 20 km for hazel grouse. In the Malozemelskaya Tundra, the northernmost black grouse and capercaillie were found in spruce forest islands, while the hazel grouse inhabited riverine floodplain forests. In the Bolshezemelskaya Tundra, the capercaillie was the only grouse bird found further north compared to the published data, in the extremely northern islands of the forest within the Shapkina River valley. In the Bolshezemelskaya Tundra, new registrations of the grouse (200 km) and ruffed grouse (100 km) were noted to the east of the known data, indirectly indicating an expansion of the distribution area of these birds to the north in the regions adjacent to the Nenets Autonomous Area. It was noted that the trends of expansion of the range of distribution of black grouse to the north are unidirectional with positive trends in air temperature in the Nenets Autonomous Area and with the processes of gradual overgrowth of woody vegetation in treeless areas located between the forest tundra and northern spruce forest islands.

During their journey, migratory birds need stopover sites where they can replenish their energy stores. Mosaic forests of agricultural areas, often planted with non-native trees, can provide opportunities for birds to do this. In the present work, I sought to answer the question of the importance of these habitats for migratory birds. For this reason I studied the stopover ecology of 15 species of long- and short-distance migratory passerines. I calculated the minimum stopover duration and the extent of fat accumulation per species and by dividing species into different groups by habitat use and migration distance. For three species, I also estimated their possible flight ranges based on the accumulated fat, body mass and wing length. My results show that the planted oleaster forest has a different role in the stopover habits of the species studied. The body mass of the birds typically did not changed significantly during the time they spent in the area. Forest and farmland species spent the longest time in the area. Despite the possibly high rate of intra- and inter-specific competition, the area can provide sufficient food for birds throughout the whole period. Short-distance migrants stored less fat than long-distance migrants, probably due to the different migration strategies. Flight distances varied according to the migratory habits of the species. From a conservation biology point of view, the study highlighted the role of these habitats in bird migration.

Relationships between members of the parasitic system formed by the taiga tick Ixodes persulcatus (Schulze, 1930) at the preimaginal developmental stages, Borrelia garinii and small mammals were studied. Transovarial transmission of B. garinii in the taiga tick was not found. In natural biotopes of northwestern Russia, small mammals that were hosts of the preimaginal stages of Ixodes persulcatus included Myodes glareolus (Schreber, 1780) (52–53%), Sorex araneus Linnaeus, 1758 (33–34%), and Apodemus uralensis (Pallas, 1811) (14%). Larvae and nymphs were most numerous on hosts at the beginning of the season, in May and June. Subsequently, their number decreased by 5–10 times and slightly increased in September. In populations, up to 31.9% of M. glareolus individuals and 20.5% of A. uralensis individuals were infected with B. garinii. The aggregated type of distribution of taiga tick larvae and nymphs on hosts has been revealed. Infection of the main part of hungry larvae and nymphs occurred at the beginning of the activity season after wintering when feeding on overwintered infected hosts. This period is the key in circulation (exchange between vectors and reservoir hosts) and the preservation of B. garinii in the natural focus of borreliosis in northwestern Russia. Vertical transmission of B. garinii is possible from larvae and nymphs fed at the beginning of the season to nymphs and adult ticks that had molted in August-September, respectively. Horizontal transmission of the pathogen from small mammals, especially the bank vole, to larvae and nymphs, and vice versa, ensures the circulation and persistence of B. garinii in natural foci. The question of the preservation of the pathogen in overwintering preimaginal stages of ticks requires further research.

The genus Icelus Krøyer, 1845 includes 18 valid species from shelf and upper slope of the northern Pacific, Arctic and North Atlantic. The taxonomy of the genus is under development. To solve taxonomic problems, there is a need to clarify the diagnostic characters of already known species. As it turned out, information about the composition of the type series of the Okhotsk sculpin I. ochotensis Schmidt, 1927 from different sources is contradictory, and the diagnostic characters in the latest revision of the genus and in the keys for species identification diverge from the original description. The work clarifies the composition of the type series of the Okhotsk sculpin from the ZIN collection (36 specimens), provides a redescription and diagnosis; the Lectotype No. 21898 is designated. Icelus ochotensis, characterized by the presence of only two rows of large scales on the body (dorsal row Dl and lateral line Ll), was included in the group “I. bicornis”, along with I. spatula Gilbert et Burke, 1912, I. uncinalis Gilbert et Burke, 1912 and I. stenosomus Andriashev, 1937. Contrary to results of the latest revision of the genus and modern identifying keys, on the top of its head there is not one pair of spines, but two pairs (parietal and nuchal ones), in the form of blunt tubercles hidden in the skin. The dorsal row of scales (Dl) in front is complete (reaches the head); lateral line begins under scales 3rd–4th of the dorsal row and does not extend posteriorly onto caudal fin; scales Ll below the canal pore are immersed in the skin and usually not serrated (one or two tiny spinules may present); supraorbital cirrus (skin appendage) is simple. The urogenital papilla of males is cylindrical, in contrast to the spatulate one in I. spatula. Vertebrae 37–40, D VII–IX 15–19, A 13–16, P 17–18, Ll 38–40, Dl 29–34; axillary scales 6–13. The distribution of the Okhotsk sculpin requires revision, since modern keys for Icelus identification contain incorrect characters for this species (one pair of spines on the top of the head).

A new effective method for sex determination of immature mouse-like rodents of the hamster family has been used (Cricetidae Fischer, 1817) based on physical impact on the urinary perineal area. The 212 immature specimens of five rodent species was tested: Myodes rutilus Pallas, 1779, M. glareolus (Schreber, 1780), Alexandromys oeconomus Pallas, 1776, Agricola agrestis (Linnaeus, 1761), Myopus schisticolor (Lilljeborg, 1844). Verification of the new method was provided using a control dissection of the studied samples of rodent. The effectiveness of express method of sex determination for under yearling rodent was 88.5–100% among samples of studied species. The effectiveness of morphological characteristics (body weight and length, anogenital distance) was 76.2–93.5% in the sex identification and only for four studied species. The new method was more successful than morphometric methods in sex determination for studied samples of immature M. schisticolor and M. glareolus by 19% and 6.8%, respectively. The close results had been detected for both methods in sex determination of M. rutilus. For sex determination of immature specimens of A. agrestis the morphometric characteristics effectiveness was 4.6% higher compared to the new method. For studied samples of A. oeconomus only the new method of sex determination of an under yearling specimens was effective. The preference in choose of non-anatomical method of sex determination of immature specimens of Cricetidae family is directly depends on the species of study rodent. The new method can be used in studies with vital animals.

We conducted a comparative analysis of qualitative composition of the Buzuluk Pine Forest avifauna, mainly based on data collected by ornithologist E.P. Knorre for the period 1928–1941, and modern observations done between 2000 and the present. Retrospective data were obtained from the now-defunct Buzuluk Bor Reserve with an area of 10 503 hectares (now Borovoye-Opytnoe Forestry in the Orenburg Province). Present-time personal avifaunistic observations (using standard methods with referring to literature sources) were carried out on an area of 49 000 hectares, both in Borovoye-Opytnoe and in several adjacent forestries that were part of the Buzuluk Bor National Park within the Orenburg Province. Comparing the historical and current bird lists, we used a relative assessment of changes in the composition of various bird groups based on the observed and expected frequencies according to the χ² test. Long-term data on average annual temperatures and precipitation from a nearby state weather station were also used. As a result, it is shown that by now the list of birds of E.P. Knorre decreased from 153 to 109 species (28.8%). When comparing by orders, the water birds were found to be the most affected group. The number of species in orders Podicipediformes, Ciconiiformes, Gruiformes decreased by 80–100%, and it dropped by more than 50% in orders Anseriformes and Charadriiformes. There was also a slightly smaller decrease in the number of species in orders Falconiformes and Strigiformes – by about 40%. An assessment of the relative changes in various bird groups from Knorre’s list based on expected and observed frequencies showed significant differences in the portion of avifauna associated with water. It decreased between 23.5% and 9% in the group ‘Limnophiles’ (χ² = 11.7, df = 1, p = 0.0006) and between 24.8% and 9% in the group of orders represented by waterfowl and waterbird species (χ² = 13.4, df = 1, p = 0.0002). The change in the portion of birds of prey was statistically non-significant. The same portion assessment method did not statistically confirm the decrease in the rest ecological and order groups. Comparison of groups by occurrence status found no significant changes in the portions of all groups of birds in the past and present, but the largest reduction was recorded in the group of migrating species. The portion of migrants decreased from 8.7% to 3.0% (χ² = 3.2, df = 1, p = 0.07, Yates corrected χ² = 2.2, p = 0.1). A dramatic decline in group of bird species associated with wetlands was suggested to be due, among other factors, to the progressive desiccation of the Buzuluk Pine Forest, as E. Knorre himself wrote in his report. The ongoing aridization of the climate, as shown by the graph of average annual air temperatures, has been taking place since at least the 20s of the twentieth century and led to the drying-up of wetlands, and also to migration of groundwater to deeper horizons. The emerging trend towards a reduction in the portion of migrants could be explained by the fact that a number of migratory bird species, mainly ducks and waders, disappeared in the study area, and several other migrants began breeding species. In addition, large-scale fires and logging led to formation of burned wasteland areas inside the forest at the beginning of the twentieth century and also probably contributed to fragmentation and desiccation of this biome.

The complexity of the structure of the dental surface of the first lower molar (m1) of mainland and island populations of the reed vole Alexandromys fortis (Büchner, 1889) was assessed using two different methods. Using the traditional approach and methods of geometric morphometry (GM), the morphological variability of the anteroconid m1 of this species of the mainland (the south of Primorsky Krai) and the islands of the Peter the Great Gulf was analyzed. The traditional approach was based on describing the folding of the occlusal surface using three features: 1) folding of the lingual side of the anterior unpaired anteroconid loop (AC); 2) the shape of the labial side of the AC; 3) the shape of the fourth lingual reentrant angle. On the mainland part of the species' range, the highest occurrence was shown by morphotype III-C-a, which also predominated in the Late Pleistocene samples of the species in Primorye. The research revealed increased morphotypic diversity in island populations of the reed vole, which is probably due to the phenotypic and genotypic characteristics of the founders of island populations, as well as inbreeding, which can cause the release of hidden diversity and an increase in the number of rare morphotypes. The most numerous morphotype on the De Livrona – Durnovo Islands was II-C-a, rare for the mainland. In general, the most complex forms are present on the islands. Using a geometric morphometry approach, the anteroconid was divided into two separately studied structures: the anterior unpaired loop of the anteroconid (AC) and the base of the anteroconid (AB). The distribution of AC configurations in the space of the two principal components took on an arcuate shape, revealing a “forbidden zone.” The main changes occur on the lingual side of the AC. Regression analysis showed a direct relationship between the length of the contour (mm) and the complication of the shape of the anterior unpaired loop. The base of the anteroconid (AC) also undergoes transformation: it either stretches or contracts, while if the anterior unpaired loop of the anteroconid (AB) is more complex, then simplification and compression of its base is observed (negative regression). Analysis of the results of using two approaches, traditional and GM methods, in the analysis of the variability of the anteroconid section m1 of A. fortis showed extreme subjectivity in the use of the first one and the wide possibilities of the second one for identifying different aspects of molare transformation using mathematical methods.

New material on the planthopper species, Bolbossus bervoetsi Gnezdilov et Bourgoin, 2016 (Issidae, Issinae, Parahiraciini), originally described more than 100 years ago based on an adult of unknown sex from the Baltic amber, is redescribed and illustrated based on a female and fifth instar nymph recently discovered in the collection of the Natural History Museum of Denmark (Copenhagen).

In the Neva River estuary, 188 species and taxa of a higher rank of benthic animals were found, of which 129 were found in the eastern part of the Gulf of Finland. At present, the zoobenthos of the estuary is dominated by eurybiont species inhabiting polluted waters. We used integrated index IP' specially devised for water-bodies and rivers of the north-western Russia to assess the water quality and a state of ecosystems of the Neva estuary. It is based on structural parameters of zoobenthic communities and makes it possible to take into consideration the pollution by toxic and organic substances. On average the water quality of the Neva Bay assessed from IP′ values was relatively stable during 1994–2021. It was assessed as “polluted” with the exception of 2006 and 2015 caused by large-scale dredging works. In the period 1982–2021, the average number of zoobenthos species at one station in the Neva Bay almost doubled, from 12 ± 1 species in 1982 to 23±2 species in 2020. In the resort area of the eastern Gulf of Finland, the values of species richness and the Shannon index were much lower than in the Neva Bay, and on average for one station varied from 5±0.6 to 14±4 species and from 1.1±0.2 to 2.3±0.2 bit/ind. This is caused by the influence of salinity, eutrophication and pollution, and invasion of alien species. In addition to intense anthropogenic impact, the dynamics of the state of zoobenthos in this part of the estuary was determined by climate fluctuations.

There are several external and internal abnormalities that affect development in both wild and farmed fish. One of these abnormalities is known as saddleback syndrome (SBS), characterized by abnormalities in the shape, number, or absence of dorsal pterygiophores, causing a concavity in the dorsal region and absence of fin sections. The causes of this syndrome are not yet clear, but could be caused by fishing or predator damage, nutritional deficiencies, genetic conditions and environmental stress from pollutants that may cause alteration in the ontogenetic development of the fish. This study recorded for the first time the SBS in a wild-caught specimen of Thorichthys meeki Brind, 1918 (Cichlidae). Specimens were collected in the locality of Chekubul, municipality of Carmen, Campeche, México on November 18, 2022. The development of the dorsal fin begins from the first to the ninth dorsal spine where there is a dorsal concavity, which ends with the last three dorsal spines. There is no evidence of scoliosis or lordosis from the X-ray analysis; however, the dorsal pterygiophores show irregularities in their development. The specimen with the syndrome showed no other body abnormalities that would have prevented its development to adulthood, although the causative agent is unclear.

Characteristics of the karyotype and early meiosis of two males of the cryptic “western” form of the viviparous lizard (Zootoca vivipara Lichtenstein, 1823) (genus Zootoca Wagler, 1830) with multiple sex chromosomes (female Z₁Z₂W/Z₁Z₁Z₂Z₂ male) were examined. The data obtained were compared with 1) those of the males of the same cryptic form from other locality, with 2) those of the males of other cryptic form also possessing the multiple sex chromosomes and with 3) those of the species of closely related genus Takydromus Daudin, 1802 with simple sex chromosomes, ZW/ZZ. Multiple sex chromosomes may influence meiosis and play a role in isolation. The males of cryptic western form of Z. vivipara studied revealed the karyotype with 36 acrocentric chromosomes (2n=36A). In early meiosis the spreading of synaptonemal complexes (SC) of the bivalents of these males were obtained and analyzed. Eighteen SC were observed, including SC of the Z₁Z₁ (pair 6) sex chromosomes. Characteristics of SC are compared with the number and the shape of bivalents and chromosomes at the diakinesis and metaphase 11 stages of the meiosis of the males from other population and with those in the other cryptic Russian form of the species. Comparative analysis of two cryptic forms has demonstrated some differences in the morphology of SC Z₁Z₁ sex chromosomes at the early stages of prophase 1 of meiosis (the late zygotena – the middle pachytene stages). However both the SC of sex chromosomes and SC of all remained chromosomes were fully synapted. All 18 bivalents were regular segregated forming haploid spermatocyte II with18 chromosomes, including two sex chromosomes (n=8, Z₁Z₂) Thus characteristics of karyotype and early meiosis of the males of western form belonging to different localities are fully coincident with those of Russian cryptic forms of Z. vivipara with multiple sex chromosomes as well. However, these features were differed from those for the species of the closely related genus Takydromus with simple sex chromosome system (ZW) where some disturbances in the course of mitoses and meiosis were observed. The results are in agreement with those suggested previously about the genomic factor(s) stabilizing the meiosis and the maintenance of multiple sex chromosome in the different cryptic forms of complex Z. vivipara.

Biophysical changes occurring in Arctic marine ecosystems under the influence of climatic factors may affect cetaceans staying here. For this reason, the urgent task is to conduct regular monitoring of marine mammals in order to assess the state of their populations and preserve the biodiversity of species. We analyzed the results of ship-based surveys of marine mammals carried out by the Polar branch of VNIRO in January–March 2019–2023 in the south of the Barents Sea and compared them with the observation data of earlier years. As the studies have shown, the winter cetacean fauna is currently represented by six species of baleen Mysticeti and toothed Odontoceti whales. White-beaked dolphin Lagenorhynchus albirostris Gray, 1846 was the most abundant and widespread species among all cetaceans; however, since 2022 we have seen a decrease in both the number of observations and abundance of this species. Fin whale Balaenoptera physalus Linnaeus, 1758 and killer whale Orcinus orca Linnaeus, 1758 were regularly registered in the study area, while sightings of harbor porpoise Phocoena phocoena Linnaeus, 1758 and humpback whale Megaptera novaeangliae Borowski, 1781 were single. Comparative analysis of the obtained data with the materials of 2012–2013 revealed some changes in the cetacean fauna that occurred during the last decade. In the waters of the southern part of the Barents Sea, there began met species that had not been previously recorded in our surveys, first of all, minke whale Balaenoptera acutorostrata Lacépède, 1804 and humpback whale. The materials we collected expanded our understanding of cetaceans staying in the western sector of the Russian Arctic during the winter.

The results of trapping, measuring the size and weight of the body of the European Nightjar, as well as migration routes according to the data of the ringing in the Kaliningrad region during 1957–2016 are discussed. The annual number of migrating birds has fluctuated significantly for 60 years, and the number of those caught and ringed varied from one to 44 individuals in different years. They were most numerous in May, in the period 1969–1981. Four ring recoveries of Nightjars ringed by us were obtained, which gives the effectiveness of ringing of this species with nocturnal activity of only 0.92%. However, these ringing results indicate that in autumn the migration routes of Nightjar population from the western parts of Scandinavia and from southern Finland run through the eastern coast of the Baltic Sea, and later, on the way to Africa, their azimuth of flight varies from 178° to 203°. The longevity record according to the data from one male of the subspecies Caprimulgus europaeus zarudny E. Hartert, 1912 was 15 years. The migration routes of this species are discussed according to the latest literature data.

This paper focuses on the fine structure of mother sporocysts, the least studied stage of the digenean life cycle. The ultrastructure of the tegument of mature mother sporocysts of Bunocotyle progenetica was examined by transmission electron microscopy and described in detail. The tegument of these parthenitae is represented by an outer anucleate syncytium connected with the deeper-lying tegumental cells by cytoplasmic bridges. Its outer plasma membrane forms minute leaf-like outgrowths and numerous deep invaginations in the shape of interconnected channels. These channels, which pass in various directions and permeate almost the entire outer syncytium, considerably amplify its surface area. The cytoplasm of the outer layer of the tegument contains large mitochondria, microtubules and rare dense secretory granules, whose contents are discharged into the lumen of the channels. Numerous pinocytotic vesicles originate from the plasma membrane of the channels. Small endocytic vesicles are transported along the cytoplasmic bridges to the tegumental cells, where endocytosed food material is sorted and broken down. These cells are characterized by a well-developed Golgi apparatus, which is represented by multiple stacks of cisternae, and the presence of numerous endosomes at different maturation stages and residual bodies. Some steps of endosomal maturation in the tegumental cells were traced. In addition to their digestive activity, tegumental cells produce secretory granules, which are transported to the outer syncytium after their maturation. It was shown for the first time that in mature parthenitae, the population of tegumental cells could be renewed at the expense of a reserve pool of undifferentiated cells. The ultrastructural features of the tegument of mother sporocysts of B. progenetica are discussed in light of the concept of the enhanced trophic function of the tegument in sporocysts lacking the alimentary canal.

The following data was acquired from literary sources and obtained by us as a result of field studies on the distribution, stationality, abundance and reproduction of voles of the genus Blanfordimys Argyropulo, 1933: Afghan vole B. afghanus (Thomas, 1912) with subspecies B. a. afghanus and B. a. balchanensis (Heptner et Shukurov, 1950), Bukhara vole B. bucharensis (Vinogradov, 1930), with subspecies B. b. bucharensis and B. b. davydovi (Golenishchev et Sablina, 1991) and Pamir vole B. juldaschi (Severtzov, 1879) with subspecies B. j. carruthersi (Thomas, 1909) and B. j. juldaschi in natural conditions on the territory of Turkmenistan, Tajikistan and Kyrgyzstan. According to the elevation gradient from low to high altitude, these voles are distributed as follows: Afghan, Bukhara, Pamir, respectively. The features of reproduction and postembryonic ontogenesis in captivity have also been studied. Reproduction took place year-round with low intensity: the number of newborns in the litter of all the species considered is small, 3 cubs on average, the average interval between litters is about 50 days. The young of voles living at lower altitudes (B. afghanus and B. bucharensis) develop somewhat faster compared to higher-altitude ones (B. juldaschi). In general, the studied species showed signs of slow development and delay in the appearance of the most important signs in postembryonic ontogenesis (eruption of incisors, epiphany) compared to most of the lowland representatives of the Arvicolini tribe voles. These features are more pronounced in B. j. juldaschi, living at high altitudes. Thus, considering the theory of pace-of-life syndrome (POLS), we observe a shift from a faster pace of life (r-strategy), characteristic of most lowland rodents, to a slower one (k-strategy). The vulnerability of voles of the genus Blanfordimys in the process of climate aridization and in conditions of anthropogenic pressure is noted.

Preparation techniques are given for making permanent or nonpermanent microscope slides of the mosquitoes and the blackflies (Diptera: Culicidae: Simuliidae). We mention here only those that we have personally found to be most satisfactory in the order to further study the morphology of dipterans. These techniques are required for a detailed examination of the diagnostic characters of mosquitoes and blackflies, as a result, to correctly identify the specimens. First, the general stages of processing specimens are considered, then the specifics for making permanent or nonpermanent microscope slides are given (in glycerin, Canadian balsam and euparal). Preparation techniques of larvae and adults (males and females) of mosquitoes and blackflies, as well as blackfly pupae, are discussed in detail, because these processes differ in each group and in each stage of the life cycle. Moreover, we give the technique for damaged material (i.e., as a result of loss of fixing fluid). For the first time, the description of diagnostic characters that are lost during the preparation is considered in detail. We have specified the structures of blackfly larvae, pupae and adults, whose characters must be described before making permanent microscope slides. We consider that some structures (i.e., the male genitalia of fam. Culicidae and Simuliidae) should be pre-examined on nonpermanent microscope slides, and then permanent slides can be made.