Fig.1. Sampling for a study of nematode populations in the canopy of a tropical monsoon forest (Dong Nai Nature Reserve, Vietnam). The forest canopy is inhabited by a variety of invertebrates, some of which are traditionally considered to be soil dwellers. These animals, along with springtails and oribatid mites, also include nematodes. A team of scientists from Syktyvkar, Tyumen, Tartu, Petrozavodsk, Ho Chi Minh City, Moscow and Kortrekos village in the Komi Republic investigated the diversity of non-parasitic nematodes in tree crowns using DNA metabarcoding. Samples were collected from different tree species in taiga, broadleaf and tropical monsoon forests, at altitudes ranging from 0.5 to 20 meters. Local (within one sample) diversity of nematodes in crowns is lower than in the soil, but the species composition varies greatly in different microhabitats. Due to this, the overall diversity of nematodes is comparable in the soil and forest canopy. “Contrary to expectations, the diversity of nematodes in the tree layer does not increase from high to low latitudes, as is observed in the soil. The taxonomic similarity between nematode communities in the soil and in the crowns is small (less than 30%). Therefore, woody habitats make a significant contribution to the overall diversity of nematodes in forest ecosystems,” said A.V. Tiunov, Doctor of Biological Sciences, Corresponding Member of the Russian Academy of Sciences, Deputy Director for Science at the IEE RAS. The article was published in the journal Biodiversity and Conservation: Kudrin A.A., Salavatulin V.M., Mikryukov V.V., Sushchuk A.A., Kudrina S.E., Kondakova T.N., Trung Duc Nguyen, Tiunov A.V. (2024) Metabarcoding reveals that arboreal habitats contribute significantly to nematode diversity in different forest ecosystems. Biodiversity and Conservation, 33: 4371–4386. DOI: 10.1007/s10531-024-02960-4.

Fig. 1. Tetraploid hybrid between the unisexual species L. guentherpetersi and the parent species L. guttata, discovered near Da Nang. Among the many animal species, only a few have abandoned males and switched to unisexual reproduction. The main advantage of the sexual process is to ensure diversity of offspring, and the refusal to recombine the genomes of different individuals in unisexual species significantly reduces the genetic and morphological diversity of individuals and provokes the accumulation of harmful mutations, which is why such phylogenetic lines gradually die out. Although most researchers believe that this is a dead-end path of evolution, leading only to short-term success, some scientists are looking for traces of gene flow between unisexual and bisexual species. Clonal lines that reproduce without males have arisen many times in both vertebrates and invertebrates. Fish and some amphibians have evolved a form of reproduction in which the eggs of unisexual species develop after stimulation by a sperm of a closely related species. This type of reproduction, in which females of the clonal form parasitize males of a bisexual species, is called gynogenesis. Reptiles are unique in that about forty species out of more than 12,000 do not require males at all and can exist independently of their closest bisexual relatives. As a rule, such unisexual species are formed as a result of hybridization. This phenomenon was first discovered by I.S. Darevsky on rock lizards (Lacertidae) of the Caucasus, and later discovered in whip-tailed lizards (Cnemidophorus), butterfly agamas (Leiolepis), some geckos (Hemidactylus, Lepidodactylus, Heteronotia) and some other genera from South America, Asia and Australia. In 2022, employees of the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (IEE RAS) began a project in which they turned their attention to butterfly agamas living in Southeast Asia. The task was to study the diversity of unisexual phylogenetic lineages and determine their relationships with closely related bisexual species. To do this, IEE RAS employees organized an expedition to central Vietnam, where one such unisexual species lives - Leiolepis guentherpetersi, which has a small range located in the vicinity of Da Nang and the ancient capital of Hue. To the north of the range of L. guentherpetersi, there is its paternal species L. reevesii, and to the south - the maternal species L. guttata. The fact that L. guttata became the mother for L. guentherpetersi was shown by colleagues earlier based on the analysis of mitochondrial DNA and was confirmed in this study. Fig. 2. Chromosomes in the studied butterfly agama species. Metaphase plates of a diploid male L. guttata, including 12 macrochromosomes (a), triploid L. guentherpetersi with 18 macrochromosomes (b), and a tetraploid hybrid with 24 macrochromosomes (c). Comparative genomic hybridization revealed that the chromosome set of triploid L. guentherpetersi includes six macrochromosomes inherited from L. reevesii (red) and 12 chromosomes from L. guttata (green) (d), while the tetraploid hybrid male (e) possessed six chromosomes from L. reevesii and 18 chromosomes from L. guttata. Scale bar = 10 µm. As a result of the analysis of dividing nuclei of the parthenogenetic species L. guentherpetersi and closely related bisexual species, the scientists determined their chromosome set (Fig. 2) and confirmed that L. guentherpetersi is a triploid species that arose as a result of repeated hybridization of a diploid parthenogenetic with one of the parents. However, which one exactly remained a mystery, which was solved by Czech colleagues from Charles University in Prague. Using the comparative genomic hybridization method, they identified the distribution of species-specific DNA of the parental individuals on the chromosomes of the triploid parthenogenetic. It turned out that L. guentherpetersi arose as a result of back hybridization with a male L. guttata, and not L. reevesii, as our colleagues from the USA had previously believed. In the spring of 2023, on a sandy beach near Da Nang, where expedition members caught several individuals of the same-sex species, they discovered a strange male, reminiscent in its coloration of both the females of the same-sex species and the male L. guttata (Fig. 1). It should be noted that males in parthenogenetic lizards sometimes appear spontaneously, so it could not be ruled out that this was one of such rare representatives of the male line. However, when testing this hypothesis, it turned out that the discovered individual had four sets of chromosomes (Fig. 2c). Genetic analysis confirmed that the caught male originated from hybridization between the parthenogenetic species L. guentherpetersi and one of the parent species. To find out which male took part in the appearance of this unique individual, an analysis of the chromosome composition was carried out. As a result, it was found that the hybrid has three genomes from the L. guttata species and one from L. reevesii (Fig. 2e). Thus, it was possible to reconstruct the history of its origin: a male L. guttata crossed with a female of a parthenogenetic species, resulting in the appearance of a tetraploid individual (Fig. 3). Fig. 3. Diagram illustrating the origin of the triploid species L. guentherpetersi and the tetraploid hybrid between this species and one of the parent species L. guttata. On the left is a schematic map showing the range of the three species studied and the location where the hybrid was found. In their study, the IEE RAS staff described for the first time the presence of a tetraploid individual in the genus of butterfly agamas, which is extremely important in itself. However, the main question is whether this male is capable of participating in reproduction. Its testes were extremely poorly developed, and there were no mature spermatozoa at all, but spermatocytes were detected. Only 18 spermatocytes were analyzed using the immunocytochemistry method. Some of the cells contained a complete set of protein skeletons formed between homologous chromosomes - synaptonemal complexes (SC) (Fig. 4). Despite the normal course of meiosis at first glance, the tetraploid bivalents had a reduced number of MLH1 foci, a DNA mismatch reparation protein whose function is to correct DNA pairing errors, i.e., to eliminate unpaired nucleotides. The absence of MLH1 signals in bivalents may lead to disrupted chromosome segregation and a block in the development of such cells. Fig. 4. Synaptonemal complexes (SC) of male L. reevesii (a), L. guttata (b) and the tetraploid hybrid (c, d). The lateral components of the synaptonemal complex were detected with antibodies to the SYCP3 protein (green); the crossing-over loci were visualized with antibodies to the MLH1 protein (indicated by arrows, red); the transverse filaments of the central space of the SC were identified with antibodies to the SYCP1 protein (magenta); chromatin was stained with DAPI (blue). The synaponemal complex of L. reevesii (a) and L. guttata (b) is represented by 18 bivalents. In the hybrid, 12 bivalents are formed by 24 macrochromosomes, and the remaining bivalents are formed by microchromosomes (c, d). Black and white (c) and color (d) images correspond to one nucleus. Scale bar = 10 µm. It is very likely that a male that combines three genomes from one species and one genome from another species is sterile, since it is unable to produce mature gametes due to genomic incompatibility. If this is indeed the case, then hybridization between triploid parthenogenetic lines and males of bisexual species probably does not lead to the emergence of fertile species, as suggested by B.L. Astaurov and I.S. Darevsky. However, to confirm this for sure, it is necessary to analyze the fertility of hybrids on a larger sample. Reference to the publication: Galoyan, E., Nazarov, R., Altmanová, M. et al. Natural repeated backcrosses lead to triploidy and tetraploidy in parthenogenetic butterfly lizards (Leiolepis: Agamidae). Sci Rep 15, 3094 (2025).

Fig.1. Appearance of caught specimens of three-toothed lamprey: a – specimen No. 1, б – specimen No. 2. D1 – first dorsal fin, D2 – second dorsal fin, C – caudal fin; rectangle – amputated caudal fin and part of the second dorsal fin. Scientists from the Kamchatka Research Institute of Fisheries and Oceanography and the Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (IEE RAS) have discovered and described the biological characteristics of the three-toothed lamprey Entosphenus tridentatus in the sea waters of the Kuril Islands. The three-toothed lamprey is a migratory parasitic species that migrates to feed in the waters of the Pacific Ocean. Its spawning grounds are concentrated in rivers along the North American coast from California to Alaska and the Aleutian Islands, as well as in the rivers of the Japanese islands of Hokkaido and Honshu. The biology of the species in fresh water has been well studied, but information on its behavior at sea remains limited, which is due to the difficulty of catching it at sea. Cases of catching two individuals of the three-toothed lamprey in the northwestern Pacific Ocean have expanded our knowledge of the morphological characteristics and biology of this species during its marine life. In June 2023, two lamprey specimens were caught in the exclusive economic zone of Russia; their external structure and tooth formula are typical for the species. Analysis showed that the specimens were immature and feeding at a depth of 32–45 m, where they followed schools of Pacific salmon. The data obtained confirm the idea of ​​significant (over 5 thousand km) feeding migrations that representatives of this species can make in marine waters. The article was published in the specialized journal Research of Aquatic Biological Resources of Kamchatka and the Northwestern Pacific Ocean.

In the Russian Caucasus, where the Persian leopards were exterminated in the 1950s, the Russian Ministry of Natural Resources, with the participation of the Sochi National Park, the Caucasus Nature Reserve, the Institute of Ecology and Evolution of the Russian Academy of Sciences, the Moscow Zoo and other organizations, as well as with the assistance of the International Union for Conservation of Nature (IUCN) and the European Association of Zoos and Aquariums (EAZA), is implementing a project to restore this predator. As a result of the reintroduction work, this spotted cat is returning to the mountainous zone of the Caucasus. The released leopards also attract wild relatives that appear here as a result of natural dispersal processes - they are recorded in areas where they have not been noted or have been noted sporadically over the past decades. Therefore, in order to continue the project to restore the leopard in the Caucasus, information on the current state of habitats and the degree of their suitability for the species in different parts of its range, which in the Russian Caucasus is its northwestern edge, is in great demand. The staff of the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (IEE RAS) carried out work for the territory of the Chechen Republic, where up-to-date information on the state of nature has been absent for objective reasons since the 1980s. Three expeditions were carried out to Chechnya, during which they performed a geobotanical description and examined the state of habitats of the main mammal species ecologically related to the leopard (its food objects and competitors), recorded traces of their presence in nature, formed sets of Earth remote sensing data (ERSD) and combined them with the collected field data. After that, machine learning approaches were applied, such as supervised classification with learning and spatial distribution modeling. The modeling was based on a preliminary prepared map of habitat types in the Chechen Republic using a combination of multi-season Sentinel-2 satellite images and field geobotanical data (Aristarkhova E.A., Kotlov I.P., Iriskhanova Z.I., Arsanukaev D.D., Yachmennikova A.A., Rozhnov V.V. Integral vegetation map of biotopes in the southern part of the Chechen Republic (using modeling) // Geobotanical mapping. 2024. pp. 44–66.). Field zoological data were combined with raster data covering the properties of ecosystems that affect the likelihood of foraging, long-distance migration and short-distance migration, and shelter conditions that are important for the range of studied species ecologically related to the leopard. In particular, this is a digital elevation model and its derivatives (climate data, anthropogenic factor, etc.). Habitat suitability for the leopard's prey species and competitors (tur, bezoar ibex, chamois, wild boar, roe deer, hare, badger, jackal, wolf and bear) was then modelled. Spatial distribution maps for each species were used to create an integrated final map, taking into account the weighted impact of each species on leopard habitat. Thus, the presence of ungulates increased the suitability of habitats for leopards, while, for example, high bear density decreased it. A preliminary assessment of the degree of habitat disturbance-fragmentation (expressed as an ecological network) was made by superimposing the habitat type map on the integrated suitability map for leopards. The study conducted by the IEE RAS staff fully assesses the territory of Chechnya suitable for the restoration of the leopard population and its characteristics. The scientists did not initially use the information obtained from the transmitter of one of the released leopards (female Khosta, released in 2022, RSO-Alania), which went beyond Ossetia, for modeling. However, to check the potential coincidence of the modeling results, they superimposed the track of this female on the resulting map and showed that Khosta used one of the few ecological corridors calculated by the IEE RAS staff on the way from Ossetia to Chechnya and back, which additionally validates the results obtained. Thus, the data obtained will contribute to the fact that the measures taken to restore the Persian leopard in Chechnya will be more accurate and effective both in matters of planning protected areas and at the level of local events, as well as in matters of making strategic decisions. Based on habitat suitability studies, as well as prey and competitor densities, there is now every opportunity to restore a sustainable leopard population in east-southeast Chechnya and adjacent Dagestan, replenished both from natural foci and from the main reintroduction site in the Central Caucasus. Publication: Rozhnov V.V., Yachmennikova A.A., Kotlov I.P., Arsanukaev D.D., Aristarkhova E.A., Magomedov M.-R.D., Weinberg P.I., Hernandez-Blanco J.A., Chistopolova M.D., Dronova N.A. Restoration of the Persian leopard in the Russian Caucasus: Suitability modeling of prey base and competitors, habitat fragmentation assessment // Biology Bulletin. 2024. Vol. 51, Suppl. 2. P. S242–S265. DOI: 10.1134/S1062359024612114

Fig.1. Hypothetical colonization routes of Natrix n. scutata after the Last Glacial Maximum (LGM), based on phylogeographic data and distribution modeling. Dashed arrows indicate possible pre-LGM migrations to putative northern refugia, while the black dashed arrow represents a hypothetical route in an unexplored area. A new study on the phylogeography of the eastern subspecies of the grass snake (Natrix natrix scutata) has shed light on how this snake species spread across northern Eurasia after the Last Glacial Maximum (LGM). A team of scientists from different organizations led by PhD E.P. Simonov from the Laboratory of Mammalian Microevolution at the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (IEE RAS) analyzed 135 individuals of the species from 91 locations, studying variations in the mitochondrial cytochrome b gene. The results showed that most of the modern range of N. n. scutata is occupied by haplotypes from one main haplogroup, which probably originated in the southern regions of European Russia or the North Caucasus. Interestingly, in Western Siberia, only one, the most frequent (ancestral) haplotype was found among 25 individuals studied, indicating a relatively recent colonization of this region. Modeling of the species' distribution showed that during the LGM, there were no suitable conditions for these snakes to live in Siberia and adjacent regions of Central Asia. However, specimens from Transbaikalia have unique haplotypes that differ from the ancestral one by one or two mutations. This suggests that grass snakes could have colonized this region during an earlier interglacial period and survived the last glacial period in this region. “Increased genetic diversity was also found in the population from the Mugodzhary Range in Kazakhstan, which may indicate the existence of a cryptic refugium in this area as well, but additional research is needed to confirm the hypotheses put forward,” said PhD Evgeny Simonov. The work was published in the journal Vertebrate Zoology: Simonov E., Lisachov A., Litvinchuk S., Klenina A., Chernigova P., Ruchin A., Bakiev A., Akhmedenov K. (2024) Recent recolonisation of West Siberia and northern cryptic refugia in the grass snake Natrix natrix scutata (Pallas, 1771) (Squamata: Natricidae). Vertebrate Zoology, Volume 74, 565–576.

The study of speciation processes occurring at the Pliocene-Pleistocene boundary in individual groups of mammals in the Horn of Africa allows us to reconstruct the picture of the evolution of biological diversity in poorly studied parts of the world. The study Phylogeny, biogeography, and integrative taxonomic revision of the Afro-Arabian rodent genus Ochromyscus (Muridae: Murinae: Praomyini) published in the Zoological journal of the Linnean Society examined in detail rodents of the genus Ochromyscus inhabiting the Horn of Africa, as well as the southeastern part of the Arabian Peninsula. Scientists from the Laboratory of Mammalian Microevolution of the A.N. Severtsov Institute of Ecology and Evolution (IEE RAS, Moscow) took part in the work  – Ph.D. Kostin D.S. and Doctor of Biological Sciences Lavrenchenko L.A. Using both genetic and morphological data, three species were identified within the genus: two in East Africa (O. brockmani and O. niveiventris) and one in South Arabia (O. yemeni). Despite their morphological similarities, it was shown that the separation of all three species from a common ancestor occurred by the middle of the Pliocene (3.5 million years ago). At the same time, the separation of species inhabiting East Africa occurred earlier, and the colonization of the Arabian Peninsula apparently occurred later, due to the presence of a relatively recent continental bridge, or the past presence of the genus along the eastern coast of the Red Sea and subsequent spread through the Sinai Peninsula. Subsequently, the disappearance of the land bridge between Africa and the Arabian Peninsula led to the isolation of the Arabian population into a separate species - O. yemeni. The work was supported by a grant from the Russian Science Foundation. The work was published in the journal Zoological Journal: Yonas Meheretu, Ondřej Mikula, Daniel Frynta, Petra Frýdlová, Getachew Mulualem, Leonid A Lavrenchenko, Danila S Kostin, Hassan Sh Abdirahman Elmi, Radim Šumbera, Josef Bryja Phylogeny, biogeography, and integrative taxonomic revision of the Afro-Arabian rodent genus Ochromyscus (Muridae: Murinae: Praomyini), Zoological Journal of the Linnean Society, Volume 202, Issue 1, September 2024.

Advances in sequencing technologies and bioinformatics have led to a breakthrough in the study of viral diversity, but viruses of most soil animals (except ants) remain largely unstudied. Millipedes (Diplopoda, Myriapoda) are one of the most diverse (about 12,000 described species) and functionally important groups of soil arthropods. A team of virologists and zoologists from the Chumakov Federal Center, the Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (IEE RAS), and the Tropical Center studied 14 species of tropical millipedes. Complete coding genomes of 16 viruses, partial coding genomes of 10 viruses, and several viral sequences that may indicate the presence of about 50 more viruses were collected and annotated. Most of the detected viruses are very distant from viruses represented in the databases. At least eight viruses meet the criteria for a new species, and for two of them a higher taxonomic status (genus and even family) can be proposed. The work was published in the journal Viruses: Litov A.G., Semenyuk I.I., Belova O.A., Polienko A.E., Thinh N.V., Karganova G.G., Tiunov A.V. (2024) Extensive diversity of viruses in millipedes collected in the Dong Nai Biosphere Reserve (Vietnam). Viruses, 16: 1486.

Today is Russian Science Day – a holiday dedicated to the outstanding achievements of Russian scientists who have made an invaluable contribution to the development of world science. This holiday was established in 1999 in honor of the 275th anniversary of the founding of the Russian Academy of Sciences (RAS) by Peter I in 1724. This is a special day for research fellows, professors, academicians, researchers, teachers, postgraduate students, as well as candidates and doctors of science. Dear colleagues, thank you for your work and wish you interesting research and publications, ideas and inspiration! Photo: Ilya Ponomarev

The film was shot in Kamchatka on the territory of the Kronotsky Nature Reserve over the course of three years. In total, three expeditions from 2020 to 2022 lasted 26 months. When asked what this award means to the film's team, the director replied: "This high award, which the professional community has given to a film about wildlife, means attracting more attention to the most beautiful places in our country, and to the reserves that protect and cherish them like a treasure. This is a home for wild animals, we must treat it with love and respect." When the idea for the film was just in the director's plans, he paid a lot of attention to the work of the employee of the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (IEE RAS), senior researcher, PhD Anna Yachmennikova, on the study of the ontogenesis of fox cubs' behavior in the wild, which she conducted on the territory of the Kronotsky Nature Reserve from 2013 to 2017. Later, Anna joined the team of filmmakers and became their scientific consultant, including preparing the text of a popular science book dedicated to the ecology of Kamchatka foxes. Congratulations to Anna Yachmennikova and the filmmakers! We also remind you that the educational application “Kamchatka. A Story in Foxes. Anna Yachmennikova, Dmitry Shpilenok. — M., 2024” is available in the public domain.

The Atlas of Distribution of Mammals in the European Part of Russia is almost ready and will soon be published. This is the first publication in Russia that summarizes information on the distribution of mammals in the European part of Russia, collected over the entire period of zoological observations in the country. It is the result of many years of joint work by a large group of authors from scientific organizations in different cities of the country and a unique example of the successful involvement of amateur naturalists in scientific research activities. For more information, follow the link.