Photo: Press Service of the Department of Nature Management and Environmental Protection of the City of Moscow The Russian Science Foundation has summed up the results of competitions for the implementation of initiative research by young scientists. From the IEE RAS, a grant from the RSF was received by P.G. Garibyan for the project “Features of zonal differentiation of communities and faunas of cladocerans of the Russian Far East and adjacent territories”. Congratulations and further fruitful research to Petr! Grants are allocated for the implementation of fundamental and exploratory scientific research in 2025-2027 to researchers aged up to and including 33 years old, who have a PhD degree. The list of winners is available at the link: https://rscf.ru/upload/iblock/be4/g5qr0mhsoz0fngcx2ldlutkb7j29e7os.pdf

Photo source Rats of the genus Rattus are very similar to each other. Unlike most mammal species, it is almost impossible to distinguish different species by the skull. Several species of rats are known to have populated almost the entire world, having learned to live together with humans. Naturally, they are actively studied. But mountain species living far from humans have been studied much less. One of these species is the Turkestan rat. It was described from the territory of modern Kyrgyzstan, and was almost immediately combined with the Himalayan field rat. This point of view was shared by Russian-speaking authors (in passing, mentioning that somewhere there, in the Himalayas, the same rat lives, of which they saw 1-2 specimens) and all the others (who wrote that somewhere there, in the Tien Shan, the same rat lives, specimens of which someone saw). In other words, taxonomists referred to each other, but no one compared the rats of the Tien Shan and the Himalayas. The name of the rats also changed between Turkestan and Himalayan. A joint Russian-Chinese team led by A.A. Lisovsky, a senior researcher at the Laboratory of Mammal Microevolution at the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (IEE RAS), and a candidate of biological sciences, collected material on both species and conducted a full-genome and morphological comparison. Interestingly, the number of Turkestan rats has significantly decreased in recent years, so some of the material for the work was taken from old museum collections (including those from the middle of the last century). In this work, together with the Chinese company BGI, it was possible for the first time to read complete genomes with good coverage for material of this age. “As expected, a comparison of the morphology of the two species did not yield any results. However, a study of the complete genomes showed that the Turkestan and Himalayan rats, although related, differ from each other no less than other species of rats,” said A.A. Lisovsky. The division of these rats into two species returned the Turkestan rat to its long-used Latin name Rattus turkestanicus, given by the Russian scientist K.A. Satunin in 1903. The work was https://onlinelibrary.wiley.com/doi/abs/10.1111/zsc.70003 in the journal: Lissovsky A.A., Liu N., Obolenskaya E.V., Ivanova E.A. & Ge D.Y. 2025. The New Old Rat (Rattus, Mammalia) From Turkestan: Revisiting From a Genomics Perspective // Zoologica Scripta. Vol.n/a. No.n/a. Related materials: RAS: "Whole-genome study shows separate evolution of Turkestan and Himalayan rats"

Photo: E.D. Varakina at the diploma presentation (Biological Faculty of M.V. Lomonosov Moscow State University) Every year, the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences supervises final qualification works on biological and ecological topics. In 2024–2025, the following final works were prepared at the laboratories of the IEE RAS: "Analysis of the larval development of shield shrimp using the example of representatives of the genus Triops Schrank, 1803 (Crustacea: Notostraca)" – Bachelor student: Denis Alekseevich Polyakov – Scientific supervisors: PhD in Biology A.N. Neretina, DSc in Biology A.Yu. Sinev "Diversity of the genus Chirocephalus Prévost, 1803 (Crustacea: Anostraca) in European Russia" – Bachelor student: Nadezhda Nikolaevna Komova – Scientific supervisors: PhD in Biology A.N. Neretina, DSc in Biology A.Yu. Sinev "Features of the fauna of microcrustaceans (Crustacea: Cladocera, Copepoda) of the Trans-Baikal Territory" – Masters student: Elizaveta Dmitrievna Varakina – Scientific supervisors: PhD in Biology Neretina A.N., PhD in Biology Chertoprud E.S. "Identification of priority areas for the conservation of marine mammals in the eastern seas of the Russian Arctic" – Student: Gital Artem Valerievich (Lomonosov Moscow State University) – Supervisor: PhD in Biology Solovieva M.A. "Reconstruction of the evolutionary history of forest groove-toothed rats of the genus Desmomys Thomas, 1910" – Student: Buchneva Alexandra Andreevna (Timiryazev Russian State Agrarian University - Moscow Agricultural Academy) – Supervisor: DSc in Biology Lavrenchenko L.A. "Taste attractiveness of sucrose solutions of different concentrations in connection with food preferences of students" – Student: Kulyukina Sofia Sergeevna (Moscow Pedagogical State University, Institute of Biology and Chemistry) – Supervisor: PhD in Biology Klyuchnikova M.A. "Resistance of cucumber lines of Russian selection to the root-knot nematode Meloidogyne hapla" – Student: Kramarchuk Kristina Nikolaevna (RSAU-MTAA named after K.A. Timiryazev, Institute of Agrobiotechnology) – Supervisor: PhD Butorina N.N. "Resistance of table carrot lines to the northern root-knot nematode (Meloidogyne hapla)" – Student: Mezentseva Albina Ruslanovna (RSAU-MTAA named after K.A. Timiryazev, Institute of Agrobiotechnology) – Supervisor: PhD Butorina N.N. "Study of resistance of tomato lines to the root-knot nematode Meloidogyne incognita" – Student: Daria Sergeevna Nenakhova (Russian State Agrarian University - Moscow Agricultural Academy named after K.A. Timiryazev, Institute of Agrobiotechnology) – Supervisor: PhD in Biology N.N. Butorina "Comparative analysis of the helminth fauna of the digestive tract of white-tailed deer from hunting grounds in European Russia" – Student: Anton Yuryevich Danilkin (Moscow State Academy of Veterinary Medicine and Biotechnology - MBA named after K.I. Skryabin) – Supervisors: PhD in Veterinary Sciences N.V. Esaulova, PhD in Biology D.N. Kuznetsov “Chemoanalytical abilities of male Djungarian hamster Phodopus sungorus (Pallas, 1703): search for determining factors” – Student: Anton Pavlovich Zakharov (M.V. Lomonosov Moscow State University) – Scientific supervisors: Vasilyeva N.Yu., Khrushchova A.M. "Protein concentration in urine in different species of rodents depending on various factors" – Student: Daria Pavlovna Rychkova (MPGU) – Scientific supervisors: Vasilyeva N.Yu., Khrushchova A.M. “The influence of nematode community structure on fusarium fungi in the winter wheat agroecosystem” – Student: Shcherbinina D.A. (M.V. Lomonosov Moscow State University) – Scientific supervisor: Ph.D. Goncharov A.A. "The Effect of Adding Organic Mulch on the Activity of Insect Pests in the Winter Wheat Agrocenosis" – Student: Batalov D.A. (RSAU-MTAA named after K.A. Timiryazev) – Supervisor: PhD in Biology Goncharov A.A. "Registration and Primary Analysis of Electrical Activity of Adult River Lamprey Lampetra fluviatilis (Linnaeus, 1758)" – Student: Tyshchenko Alina Maksimovna (RSAU-MTAA named after K.A. Timiryazev) – Supervisor: PhD in Biology Zvezdin A.O. "Modeling of Tiger (Panthera tigris) Habitats in Khabarovsk Krai" – Student: Fomin A.D. (RGAU-MSHA named after K.A. Timiryazev) – Scientific supervisor: Ph.D. Yachmennikova A.A. “Some quantitative characteristics of the animal population of the North Ossetian Nature Reserve based on the analysis of camera trap data: monitoring within the framework of the leopard restoration project in the Caucasus” – Student: Parubok A.V. (RGAU-MSHA named after K.A. Timiryazev) – Scientific supervisor: Ph.D. Yachmennikova A.A. "Maternal behavior and physiological status of cubs during early postnatal ontogenesis in the Far Eastern forest cat" – Student: Markov Ilya Igorevich (RGAU-MSHA named after K.A. Timiryazev) – Scientific supervisor: Ph.D. Alekseeva G.S. "Ploidy of parthenogenetic offspring of Darevskia dahli (Darevsky, 1957) females from the zone of sympatry with the parental species Darevskia portschinskii (Kessler, 1878)" – Student: Elizaveta Sergeevna Mikhailovskaya (Russian State Agrarian University - Moscow Agricultural Academy named after K.A. Timiryazev) – Supervisor: PhD in Biology E.A. Galoyan "Distribution of the genus Trachelipus (Crustacea, Isopoda) in the Caucasus" – Student: Daniil Ivanovich Polyakov – Supervisors: DSc, RAS prof. K.B. Gongal'skiy, DSc, prof. A.Yu. Sinev. (M.V. Lomonosov Moscow State University) "Morphological approaches to the taxonomy of the family Agnaridae (Isopoda: Oniscidea)" – Student: Byzov Philipp Sergeevich – Scientific supervisors: Doctor of Biological Sciences, Prof. RAS Gongalsky K.B., Ph.D. Petrov P.N. (M.V. Lomonosov Moscow State University) Congratulations to our dear students on their successful defenses and excellent grades! We wish you inexhaustible enthusiasm and good luck in all your endeavors! Let every day be a reason for joy - especially biological!

Photo: IEE RAS From June 16 to June 30, 2025, employees of the IEE RAS conducted an expedition to conduct a comprehensive study of the Baikal seal on the Ushkany Islands archipelago. Photo: IEE RAS During the expedition, 20 animals were captured. Blood, fur and whisker samples were taken from all of them for further health studies. Satellite transmitters were installed on 15 animals to track their migrations. Photo: IEE RAS IEE RAS postgraduate students Polina Shibanova and Polina Ilyina, and MSU biology student Vlada Vasilyeva stayed on the Ushkany Islands until the end of July. They will be keeping records of seals on the archipelago's haulouts, as well as conducting behavioral studies to assess the impact of tourists on haulout seals. IEE RAS thanks the Federal State Budgetary Institution “Zapovednoye Podlemorye” and personally its director, Mikhail Evgenievich Ovdin, for assistance in organizing and conducting field work. Photo: IEE RAS The project was made possible by the Lake Baikal Foundation, the World Around You Foundation, the Siberian Wellness Company, and the Moskvarium Oceanography and Marine Biology Center. Related materials: RAS:  "The expedition for a comprehensive study of the Baikal seal has been completed"

From June 30 to July 11, 2025, two conference schools were held at the Deep Lake Hydrobiological Station of the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (Ruzsky District, Moscow Region) to improve the qualifications of hydrobiologists (graduate students, young researchers, and teachers): 1) At the 7th conference school "Systematics and Faunistics of Cladocera (Cladocera)" (June 30 - July 6), lectures were given by specialists and practical classes were held to determine the material within the framework of the study of cladocerans. The lectures were devoted to the morphology, biogeography, phylogeography, and the basics of the systematics of Cladocera (Ctenopoda, Anomopoda, Haplopoda, Onychopoda, Moinidae), and cladocerans were also considered as objects of paleolimnology. 2) At the 1st school-conference “Methods and problems of modern paleolimnology” (July 7 – July 11), lectures and practical classes were held on various methods of paleolimnological research (such as cladoceran, chironomid, spore-pollen analysis, as well as analysis of plant macroremains), issues of formation of taphocenoses of continental water bodies and problems of interpretation of paleolimnological data. The lecturers at the two conference schools were N.M. Korovchinsky, A.A. Kotov, P.G. Garibyan and A.A. Zharov, employees of the Laboratory of Ecology of Aquatic Communities and Invasions of the IEE RAS, as well as a number of young researchers from other institutions. The main organizer of both events was Yu.A. Pastukhova, a postgraduate student at Moscow State University, whom the IEE RAS thanks for her efforts that led to remarkable results, despite the very rainy and cool weather during the first school and the hurricane that hit the Biostation during the second school and left the school participants without electricity for two days. The audience included young specialists from various regions of the Russian Federation, including Irkutsk, Novosibirsk, Kazan, Volgograd, Vologda and other cities. A significant proportion of the participants were young workers from fisheries institutions, which indicates that the proposed topics of the schools, held annually at the Deep Lake Hydrobiological Station of the IEE RAS, are in high demand by practical science. Within each conference-school, half a day was devoted to the reports of the trainees on the topics of their research. Each participant shared interesting information about their achievements in the field of hydrobiology, cladocerology and paleolimnology, some participants also spoke about the work of their institutions. This was followed by a general discussion of the participants' reports and various problems related to cladocerans and paleoecological methods. Upon completion of both schools, the participants received a certificate of participation in the event and a lot of positive emotions! We will be glad to see young scientists at the next conference-schools of the same name, which will undoubtedly be held in 2026 and in subsequent years. Related materials: Nizhne-Obsky branch of Glavrybzavod: "A week among scientists: new knowledge and live discoveries at the "Lake Glubokoye" biostation"   VNII RHO: "A specialist from the Middle Volga branch of VNIRO took part in the work of one of the oldest domestic hydrobiological stations"

The new issue of the journal "Problems of Ichthyology" (Vol. 65, No. 3, 2025) is available for reading and downloading. Contents Morphological variability and species composition of tube-nosed gobies of the genus Proterorhinus (Gobiidae) of the Black Sea, their diagnostic features and distribution patterns within the basin E. D. Vasilyeva, V. P. Vasiliev Variability of morphological and genetic features of the anadromous black-backed herring Alosa kessleri kessleri (Alosidae) of the Akhtuba River (Lower Volga basin) in the modern period. On the issue of species structure K. V. Kuzishchin, M. A. Gruzdeva, A. V. Semenova, F. A. Fedotov, A. M. Shadrin Features of variability of some morphological traits in whitefish Coregonus lavaretus sensu lato (Salmonidae: Coregoninae) from water bodies of the southern and arctic regions of Siberia N. A. Bochkarev The first find of the hare-headed greenling Hexagrammos lagocephalus (Hexagrammidae) in the northern part of the Sea of Okhotsk M. V. Nazarkin, A. V. Shestakov, A. M. Orlov Additions to the occurrence of two rare species of sea bass of the genus Sebastes (Sebastidae) in the Pacific waters of the Kuril Islands Yu. K. Kurbanov On the capture of pelagic fish in the open waters of the northern tropical part of the Central Atlantic in autumn 2019 (based on the results of the 44th and 45th cruises of the research vessel “Akademik Nikolay Strakhov”) I. B. Shakhovskoy, D. Yu. Malikova Some aspects of the ecology, morphology and origin of the green chanterelle Podothecus hamlini (Agonidae) in the northern part of the Sea of Japan S. F. Solomatov, B. A. Sheiko, N. L. Aseeva Degradation of skeletal muscle proteins of pink salmon Oncorhynchus gorbuscha (Salmonidae) during spawning migration N. P. Kancerova, D. A. Efremov, L. A. Lysenko Morphofunctional characteristics of the blood erythron of the golden mullet Chelon auratus (Mugilidae) at the early stages of ontogenesis A. A. Soldatov, A. G. Rokotova, T. A. Kukhareva, V. N. Rychkova Taste responses of carp fish (Cyprinidae) to carboxylic acids. 2. Feeding behavior A. O. Kasumyan, E. S. Mikhailova The issue is available at the link.

As part of the corporate program of PJSC NK Rosneft for the conservation of Arctic biological diversity, called "Tamura", two scientific expeditions were conducted in the spring of 2025. With the support of Rosneft, in the areas of the northwestern part of the Taimyr Peninsula and its ice waters, scientists from the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (IEE RAS) conducted studies of the polar bear and its food sources in order to assess the condition of the animals in the context of climate change and anthropogenic impact. One of the areas of expedition research was the study of the polar bear in coastal areas and the waters of the Kara Sea in different seasons of the year. During the spring expedition of 2025, the distribution, number, age and sex composition, behavior and condition of animals in the conditions of the natural period for the polar bear - the ice period - were studied. These works were a continuation of the field work carried out under the Tamura program in the fall of 2024, when polar bears in the Taimyr areas were studied in a difficult period for the animals - the ice-free period, when they were on land and there was no opportunity to hunt seals and survive in search of alternative food sources. During the field work in the period April-May 2025, using a helicopter, full-scale aerial surveys of these endangered animals were carried out on fast ice. The Mi-8MTV-1 helicopter carried out research routes with a total length of about 5 thousand kilometers, surveyed fast ice near the islands of Sibiryakov, Neupokoev, Vilkitsky - to the west of Dikson and Rastorguev Island, Vostochny and Zapadny Kamenny, Baranova, Podkova, Sev. Plavnikovy - in the east, as well as ice in the Yenisei Gulf. A total of 37 polar bears of various ages and both sexes were recorded. Among them were a female with a one year-old cub, a female with two year-old cubs, and a female with one yearling. 15 adult bears, 6 adult males and 9 females, were captured and released after four males were fitted with ear tags, and six females were fitted with satellite collars transmitting information about the animals' locations. All polar bears captured during the expedition were measured, blood samples were taken for laboratory testing of their health and genetic affiliation to a particular group, and fur samples were taken to determine the presence of various contaminants in their bodies. In addition, the main concentration sites of the bears' main food source - seals (ringed seals and bearded seals) - were identified and encounters were recorded. All work on the territory and in the waters of the Bolshoi Arktichesky Nature Reserve was carried out in agreement with and in accordance with the Agreement on Scientific and Technical Cooperation between the A.N. Severtsov Institute and the Federal State Budgetary Institution "United Directorate of Taimyr Nature Reserves" dated March 31, 2022. State Inspector Igor Nikolaevich Kornienko took an active part in the work of the expedition group. The second part of the expedition work carried out in the Kara Sea during the same period was a full-scale census of the polar bear and marine mammal population using instrumental (photo and infrared aerial photography) and aerial visual methods from the laboratory's An-28 aircraft. The total length of the routes was almost 18 thousand km, more than 180 thousand photographs were taken. During the aerial visual observations, individuals of polar bears, walruses, belugas and more than 1000 seals were recorded. Based on the results of the aerial census, the number and distribution density of polar bears of the Kara subpopulation will be determined. Text: Ilya Mordvintsev, leading researcher at the IPE RAS, PhD in Biology Photo: Denis Zybin and Svetlana Artemyeva

Photo source: Mikhail Solovyov The research team of the Laboratory of Evolutionary Trophology of the A. N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences conducted comprehensive expeditionary research in the areas of the Sura and Ilim Rivers (Penza Region) to collect ichthyological material and samples of the digestive tract for enzyme analysis in the asp (Aspius aspius) and chub (Squalius cephalus) as examples of stomachless predators from the Cyprinidae family. The work is carried out with the support of the Ministry of Education and Science of Russia within the framework of the project under the megagrant program "Evolution of the functioning of the digestive system of ectothermic vertebrates as a mechanism for mastering a contrasting habitat." In 2022, the project of the team from the A. N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences won the mega-grant competition of the Ministry of Education and Science of Russia. At the initiative of the head of the Aquaculture Department of the Institute of Food and Agricultural Research and Technology (Spain) Enrique Gisbert Casas, the Laboratory of Evolutionary Trophology was created. The most important scientific objectives of the project include identifying key features of the functioning of the digestive system in sympatrically living related and unrelated forms/species of various groups of ectothermic vertebrates and optimizing biotechnology for the development of domestic fisheries and aquaculture. "The project includes research aimed at establishing the mechanisms of the functioning of the digestive system of lower vertebrates under the influence of various biotic and abiotic factors. An expedition to the Sura River area, the main waterway of the Penza Region, as well as the small Ilim River located in the east of the Penza Region, and the collection of planned samples of the digestive tract of asp and chub will allow us to better understand the biochemical mechanisms underlying the digestion processes in predatory fish that do not have a stomach and, accordingly, an acidic stage of digestion. As a result of the expedition, 25 and 11 different-sized individuals of asp and chub were caught, which will allow us to analyze the relationship between the studied biochemical parameters of digestive enzymes and the size and age indicators of fish. Based on the results of this work, it is planned to publish in a specialized, highly rated, international journal on fish physiology," said Mikhail Solovyov, an employee of the Laboratory of Evolutionary Trophology. According to the scientists, the study will provide new data on the features of hydrolysis of food objects by digestive enzymes of the intestines of predatory carp fish, which has been practically unexplored until now.

Photo: Press Service of the Department of Nature Management and Environmental Protection of the City of Moscow Experts are assessing the condition of the reservoir using bioindicator organisms - zooplankton and benthic organisms living on the bottom. Large-scale field research continues in the Moscow part of the Losiny Ostrov National Park. Specialists are studying the ecological and recreational condition of the Kazenny Pond. "Regular environmental studies are the basis for competent management of the capital's natural areas. The city actively supports scientific projects that help track changes in the state of flora and fauna under the influence of humans and climate. This allows us to make effective decisions - not for the short term, but taking into account the future of Moscow as a green, environmentally friendly city," said Yulia Urozhayeva, head of the capital's Department of Nature Management and Environmental Protection. Last year, a unique large-scale ecological and biological survey was conducted in Losiny Ostrov Park, including more than 80 specialists from five scientific institutes. They identified more than 1,500 species of animals and plants, of which over 200 are rare and protected. Based on the survey results, the experts gave recommendations on supporting vulnerable animal species. In addition, programs for their conservation and restoration were developed. This year, comprehensive studies of the park's nature continue. In April, a group of scientists, including specialists from the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, began studying the biodiversity of Losiny Ostrov's water bodies. The experts took samples of phyto- and zooplankton from Babaevsky Pond, as well as benthic organisms living in the soil. Then, hydrobiologists took samples of water and bottom sediments in Kazenny Pond, as well as samples of the upper layer of bottom sediments. This is done to assess the current ecological and recreational state of water bodies. It can change under the influence of external factors, which often has a negative impact on biodiversity, since the life cycle of many organisms is directly related to water. Photo: Press Service of the Department of Nature Management and Environmental Protection of the City of Moscow At the next stage, scientists in the laboratory analyze the species composition of two groups of organisms: testate amoebae (benthic organisms living on the bottom) and cladocerans (representatives of plankton). These microorganisms are bioindicators, where their presence and the structure of their populations can be used to judge the degree of pollution of a reservoir. Testate amoebae are especially sensitive to heavy metals, oil products and road salt. Cladocerans react to the general organic load. If plankton shows that the water is relatively clean, and bottom organisms indicate the opposite, this indicates the need for careful and targeted work with bottom sediments, hydrobiologists note. Photo: Press Service of the Department of Nature Management and Environmental Protection of the City of Moscow Specialists also collect deep silt samples that allow us to study how the reservoir's condition has changed over the past decades. According to scientists, the Kazennyi Pond has a high degree of overgrowth, accumulation of organic matter, and oxygen deficiency in the winter. Such conditions can harm aquatic fauna, so it is necessary to regularly monitor the reservoir's condition. Based on the data obtained, specialists develop recommendations for improving the pond's condition. One possible measure is to increase flow, for example, by supplying additional clean water or cleaning the drainage channels. This will reduce the concentration of organic matter and restore the ecosystem. It is also important that the reservoir is cleaned more than once. Without a comprehensive approach and regular monitoring, the pond's condition may deteriorate in a few years. Photo: Press Service of the Department of Nature Management and Environmental Protection of the City of Moscow "If you simply clean a reservoir, in 10 years it will be in the same condition again. It is important to improve the functioning of the entire ecosystem - so that aquatic organisms themselves process excess organic matter. This will ensure clean water, sustainable biodiversity and a favorable environment for city residents," the experts noted. The data collected during field work will form the basis for long-term environmental monitoring and the development of solutions for the restoration and maintenance of the capital's reservoirs.

Photo: Lifetime coloration of Kuban minnows Scientists from the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (IEE RAS) and the I.D. Papanin Institute of Inland Water Biology of the Russian Academy of Sciences (IBW RAS) have described a new species of minnow — Phoxinus ayukensis — with an extremely narrow range. It lives only in the upper reaches of the Ayuk Creek, which is part of the Psekups River system, a tributary of the Kuban, in a 5-7 km long section of the riverbed, limited by waterfalls and fed by karst springs with cold water. The Ayuk Creek, where the new species was discovered, originates near the Bolshaya Phanagoria Cave. The population attracted attention back in the 1930s, when researchers noticed its geographical isolation, but only modern comprehensive analysis has revealed its uniqueness. Photo: Morphological features of the Ayuk minnow The Ayuk minnow differs from other known minnows by a significantly increased number of scales in the lateral line and a high proportion of individuals with a reduced number of rays in the ventral fins. At the same time, it is characterized by a moderate genetic distance in the mtDNA cytochrome b gene from a geographically and genetically close species, also inhabiting the Kuban Basin - the Adagum minnow P. adagumicus. Photo: Ayuk Creek - habitat of a new species (top), Ayuk waterfalls (bottom) “The stable temperature of underground karst waters could have helped the species survive climate collisions, especially during glacial-interglacial periods, and its very low values (about 8 degrees) could have contributed to an increase in the number of scales. Isolation and small population size are possibly associated with the founder effect and the population passing through a “bottleneck,” which led to a decrease in genetic diversity and accelerated gene drift. This could have contributed to the rapid consolidation of mutations and the emergence of pronounced morphological differences,” said Boris Levin, PhD in Biology, leading researcher at the IEE RAS. Pictures: Map of the distribution of Caucasian minnows in the North-West Caucasus (the arrow indicates the range of the Ayuk minnow) The stream where the new minnow species lives dries up in the summer, turning into a chain of puddles. The population is vulnerable: it has low genetic diversity, and a decrease in water availability due to drought could put the species at risk of extinction. This discovery, along with the example of the Kildin cod, shows how the isolation of small populations in special environmental conditions leads to the formation of new forms and species, and emphasizes the importance of preserving the fragile ecosystems of the Caucasus, where groundwater outlets play a key role in the formation and maintenance of aquatic biodiversity. The article is published in the open access journal Zoosystematics and Evolution: A new super narrow-ranged endemic Phoxinus minnow (Leuciscidae) from the Caucasus Oleg N. Artaev, Ilya S. Turbanov, Aleksey A. Bolotovskiy, Alexander A. Gandlin, Boris A. Levin, 10.3897/zse.101.153548 , Zoosystematics and Evolution 101(3): 1137-1154. The work was supported by the Russian Science Foundation grant No. 23-14-00128. Related materials: RAS: "New fish species with very narrow habitat discovered in Caucasus" NIA "Kuban": "New minnow fish species discovered by scientists in Kuban" Nauka.mail: "New fish species discovered in North Caucasus" FishNews: "New fish species discovered in Caucasus" Krasnodar TV channel: "New fish species galyan discovered by scientists near Goryachy Klyuch" DG-Yug: "New fish species discovered in Goryachy Klyuch area" Zhivaya Kuban: "New fish species discovered near Goryachy Klyuch"   Novaya Kuban: "New fish species with very narrow habitat discovered in Kuban" 24 SMI: "Alarming discovery in Russia: new fish species may disappear after barely having had time to appear"   Komsomolskaya Pravda: "The only Phoxinus ayukensis in the world. Previously unknown to science fish species discovered by scientists in Kuban" Rambler: "Russian scientists have discovered a new species of fish in a single stream in Kuban"   Krasnodar.Media: "Scientists have discovered a new species of fish that lives only in the Ayuk stream in Kuban" TRK Rossiya: "Russian biologists have discovered a new species of minnow" Kuban 24: "Russian scientists have discovered a rare species of fish in a tributary of the Kuban"  Kuban News: "Found only in a stream: scientists have discovered a new species of fish with a very narrow range in Krasnodar Krai"   Krasnodar Izvestia: "A rare species of minnow was discovered near Goryachy Klyuch" Ministry of Education and Science: "Биологи описали новый вид рыб, обитающий только в одном ручье" Ferra: "Russian scientists have discovered a new species of fish in a single stream in Kuban"   Kuban.Press: "A new species of fish found in a stream in Krasnodar Krai" Expert.Yug: "A rare fish found only in Krasnodar Krai was found in a stream near Goryachy Klyuch"   Zhukovsky.Life: "A new species of minnow with a narrow range was found in the Caucasus"