Russian Journal of Biological Invasions

2026, issue №1

CONTENTS

TERRESTRIAL MOLLUSKS OF ROADSIDE BIOTOPES IN THE WESTERN CAUCASUS: A TRANSPORT VECTOR FOR DISTRIBUTION INTO OTHER REGIONS - Adamova V.V., Kustova M.I. - The dispersal of alien species often occurs via road and rail transport. Although snails and slugs are slow-moving animals, many species of terrestrial mollusks can survive such a transportation and can therefore cover long distances. The Caucasus is a source region for alien snails and slugs in European Russia and adjacent territories not only due to the rich biodiversity but also due to the well-developed transportation network. In this study, roadside biotopes along railways and highways in the Republic of Adygea and Krasnodar Krai were surveyed and the diversity of the mollusk communities was assessed. Six species of terrestrial mollusks were found along both roads and railways, with the number of individuals in a single area reaching 110/m². The most abundant was the steppe species Xeropicta derbentina. Land mollusks are 1.84 times more likely to be found along railways than along roads, as confirmed by regression analysis (p=0.001). These results confirm the association of several Caucasian land mollusks with road infrastructure biotopes.

NEW SPECIES OF THE MUD CRAB EURYPANOPEUS DEPRESSUS (SMITH, 1869) (BRACHYURA: XANTHOIDEA: PANOPEIDAE) IN THE SEA OF AZOV - Afanasieva M.S., Simakova U.V., Timofeyev V.A. - The presence of Eurypanopeus depressus (Smith, 1869) was recorded for the first time in the Sea of Azov during a taxonomic revision of mud crab specimens (fam. Panopeidae) collected between 2022 and 2024. Previously, this species was known only from the Atlantic coasts of America and the western Black Sea. DNA sequences of two nuclear (18S, H3) and two mitochondrial (COI, 16S) gene regions were obtained from the collected individuals, enabling the assessment of genetic diversity and the calculation of genetic distances. The study presents data on the distribution and morphological variability of specimens from the Sea of Azov, along with a detailed description of their preferred habitats. Diagnostic morphological characteristics are provided to facilitate identification of all non-native mud crab species in the Azov–Black Sea region. The presumed pathways of introduction and subsequent dispersal of the species are discussed, as well as its potential ecological role and significance in the Sea of Azov.

COMPREHENSIVE ANALYSIS OF INVASIVE FLORA OF RUSSIA - Vinogradova Yu.K., Senator S.A. - The article presents the results of an analysis of the invasive flora of Russia based on the materials contained in the database "IRIS: study of plant invasions of the country". The taxonomic, biomorphological, and chorological structure of the invasive flora, as well as the duration of growth of the most aggressive species in their regions of occurrence, has been analyzed. Invasive species (586 species from 351 genera and 87 families) are considered as a group of alien naturalizing neophytes: archaeophytes and ephemerophytes are not included in this category, as well as native species that cause ecological, socio-economic damage. The invasive flora is characterized by the predominance of unintentionally introduced North American species, which spread from the secondary ranges previously formed in Europe. The leading families in terms of the number of species are Asteraceae, Poaceae, Fabaceae, Rosaceae, Brassicaceae, Amaranthaceae, Apiaceae, Lamiaceae, Boraginaceae, Plantaginaceae. Annual herbaceous plants are the leaders in the spectrum of life forms (42%), the proportion of perennial herbaceous plants is lower (34%), woody plants are less represented (24%). In the chorological spectrum, the leading position is occupied by widespread species with Eurasian (32%), American (19%) and Asian (15%) types of natural ranges. The features of the distribution of the taxonomic and life forms of invasive species according to federal districts are described. There are relatively few species with the Holarctic type of range, as well as hemicosmopolitan species, which does not confirm the existing hypothesis of a more successful invasion of species with the wide primary ranges. In the chorological spectrum, the leading position is occupied by widespread species with Eurasian (32%), American (19%) and Asian (15%) types of the natural ranges. However, there are relatively few species with the Holarctic type of range, as well as hemicosmopolitan species, which demonstrates that the hypothesis of more successful invasion of species with a wide natural range is not universal. Erigeron canadensis and Acer negundo are the longest-standing invasive species. Their first herbarium specimens were collected in 1781. The duration of growth of invasive species varies from 2 to 220 years. A tendency to reduce the duration of growth of alien species during their subsequent dispersal in the country was noted. A new indicator "the index of invasiveness of the territory" is proposed. This indicator reflects the degree of negative impact of alien invasive species. It is noted that the Central and Volga federal districts are most affected, and the North Caucasus federal district is least affected. The article highlights the current state of plant invasions in Russia, identifies gaps in research, and outlines ways for further research to document invasions of alien plants.

THE FIRST RECORD OF OBESOGAMMARUS CRASSUS (G.O. SARS, 1894) (AMPHIPODA) IN LAKE ILMEN - Ivicheva K.N., Soldatenko E.V., Besaeva E.A. - In 2024, the Ponto-Caspian amphipod Obesogammarus crassus (G.O. Sars, 1894) was first discovered in Lake Ilmen in the Novgorod region. It is assumed that it was introduced into the lake from the mouth of the Dnieper River in the early 1980s, together with other species of crustaceans. Previously, in the North-West of Russia, this species of crustacean was recorded only in the Kaliningrad region. In Lake Ilmen, this invading species was found in the littoral zone on hard substrates in thickets of higher aquatic vegetation. The morphology of Lake Ilmen specimens of O. crassus has been studied in detail by light and scanning electron microscopy. The studied specimens revealed deviations in a number of morphological characters compared to the original description of the species, which may be due to better preservation of the material and the higher resolution of electron microscopy, or may reflect existing intraspecific variability.

THE SHRIMP PALAEMON MACRODACTYLUS IS A NEW SPECIES OF THE WESTERN SEA OF AZOV FAUNA IN THE WATERS OF ELEVATED SALINITY - Koulish A.V., Saenko E.M. - The shrimps Palaemon macrodactylus have been seen for the first time in the estuaries of the western Sea of Azov (Sivash Bay, Molochny Estuary) characterized by water with increased salinity (≥ 30%). The caught shrimps were females with a total body length ranging from 39.9 to 61.0 mm. They were described morphologically, their biological features were also given, in particular, maturity of gonads and nutrition specificities. The possible ways of invasion and vectors of subsequent spread of Palaemon macrodactylus in the Sea of Azov were traced. The potential place of this species in the ecosystem of the Sea of Azov is discussed.

INVASION RANGE EXPANSION OF THE SEED-BEETLE ACANTHOSCELIDES PALLIDIPENNIS (MOTSCHULSKY, 1874) (COLEOPTERA: CHRYSOMELIDAE: BRUCHINAE) IN KYRGYZSTAN - Lopatina S.V., Babiuk R.S. - For the first time in Kyrgyzstan, the North American species of seed beetle Acanthoscelides pallidipennis (Motschulsky, 1874) was bred from the beans of the indigo bush Amorpha fruticosa L. (Fabaceae), collected in 2025 on the territory of an ornamental plant nursery in the Chui Region. The level of seed damage was 19.5%, emergence of adults was recorded in November. In addition, the parasitoid Pteromalus sp. (Hymenoptera: Pteromalidae) was found in the indigo bush collections together with the beetles.

LAMPRODILA FESTIVA (LINNAEUS, 1767) (COLEOPTERA: BUPRESTIDAE) IN JUNIPER WOODS OF THE STATE NATURE RESERVE OF REGIONAL SIGNIFICANCE "ISTISU-KAKA" (REPUBLIC OF DAGESTAN) - Sadykova G.A., Aliev Kh.U. - The paper presents information about the threatening spread of an invasive pest of the Cupressaceae family – the cypress rainbow borer (Lamprodila festiva (Linnaeus, 1767) and the first finding of the pest on the territory of the State Nature Reserve of regional significance "Istisu-Kaka" (Republic of Dagestan). Reconnaissance studies conducted in 2025 in juniper sparse forests of Foothill Dagestan on an area of more than 80 hectares on the territory of the Nature Reserve "Istisu-Kaka" revealed damage to individuals of the Red Book species of Dagestan and Russia Juniperus polycarpos C. Koch and resource species Juniperus oblonga M. Bieb. As a result of examining about 250 individuals of juniper and processing more than 30 sections, signs of damage characteristic of both species were identified: browning of needles; drying out of individual branches of the crown; flight holes; thickening of shoots in the area of larval laying and caterpillar maturation; caterpillar passages and destruction of wood; drying of the bush. The percentage of healthy, affected and dry individuals (5%, 15%, 80% for J. oblonga and 15%, 35%, 50% for J. polycarpos, respectively) in the population was determined. Taking into account the rate of spread of the pest Lamprodila festiva, the scale and degree of damage to individuals of the genus Juniperus in the population and the absence of phytosanitary measures, we can speak about complete degradation and possible disappearance of juniper populations in the territory of the Istisu-Kaka Nature Reserve and Foothill Dagestan as a whole within a 5-10-year period.

FIRST DETECTION OF THE INVASIVE AMPHIPOD GMELINOIDES FASCIATUS (CRUSTACEA: AMPHIPODA) IN THE VYGOZERSKOE RESERVOIR AND THE WATER CATCHMENT OF THE WHITE SEA–BALTIC CANAL (REPUBLIC OF KARELIA) - Sidorova A.I. - The Vygozero Reservoir is located in the Subarctic territory, the north of the European part of Russia, and is a component of the White Sea-Baltic Waterway. The results of studies of the littoral bottom biocenoses of the Vygozero Reservoir, Lake Voitskoe and the Segezha River in June 2025 are presented. It is shown that the invasive species Gmelinoides fasciatus (Stebbing 1899) (Crustacea: Amphipoda) was identified at littoral stations located close to shipping routes. The fairly rapid dispersal of the Baikal species G. fasciatus to the littoral of other water bodies gives reason to assume that in the coming years these amphipods may colonize the entire littoral zone of the Vygozero Reservoir.

ICHTHYOFAUNA OF ALAKOL LAKE SYSTEM AND WAYS OF ITS FORMING. A REVIEW - Sokolovsky V., Timirkhanov S., Pazylbekov M. - The review describes all findings of alien fish species in the water bodies of the Alakol lake system. Since 1932, 25 fish species have been introduced here, nine of which were introduced intentionally, while the rest were released accidentally. In the 20^th century, species were introduced to increase fish productivity of the lakes. Currently, fish are introduced accidentally, due to the transboundary transfer of new species along the Emel River from the People's Republic of China. The naturalization of invasive species has led to the displacement of native species from the terminal water bodies in the lowlands to the foothill zone and overgrown biotopes of water bodies. The endemic species, Balkhash perch, remains abundant in a deeper part of Lake Alakol and in the overgrown biotopes of adjacent water bodies. The fact that predators capable of hunting in overgrown biotopes (pike, Amur catfish, and snakehead) have appeared in Lake Alakol in recent years poses a threat to perch populations in overgrown biotopes. If a predator capable of colonizing the deep-water zone of Lake Alakol with its salinity of up to 11‰ is introduced, the fish species is assumed to pose a threat to continued existence of the high-abundant population of Balkhash perch. The article has proposed measures to reduce the risks to the existence of high-abundant populations of Balkhash perch in the water bodies of the Alakol lake system.

THE ROLE OF DIFFERENT FISH SPECIES IN THE CONSERVATION OF NUMBERS OF HEMIPOPULATIONS OF METACERCARIAE OF THE TREMATODE APOPHALLUS DONICUS (SKRJABIN ET LINDTROP, 1919) IN THE ECOSYSTEMS OF RYBINSK AND GORKY RESERVOIRS (UPPER VOLGA BASIN) - Tyutin A.V., Shlyapkin I.V., Bazarov M.I., Morozova D.A., Medyantseva E.N., Tyutin V.A. - This article describes a circle of the second intermediate hosts of the alien trematode Apophallus (=Rossicotrema) donicus Skrjabin et Lindtrop, 1919, as well as patterns of the development of rossicotremosis (a type of “black-spotted” fish disease) in the Upper Volga foci in 2019–2022. Using the example of Rybinsk and Gorky reservoirs, the host differences in the distribution of A. donicus metacercariae in pelagic and coastal groups of the most abundant Percidae species are considered. The most common second intermediate host of A. donicus in both reservoirs was the perch Perca fluviatilis Linnaeus, 1758. It is shown that the high variability in the occurrence of A. donicus metacercariae usually reflects the mosaic pattern of distribution of the first intermediate host of the trematode, the Ponto-Azov prosobranch mollusk Lithoglyphus naticoides (C. Pfeiffer, 1828). In the case of the Rybinsk Reservoir, we found no evidence of significant foci of rossicotremosis outside the relatively small area of the Volga Reach. In adult perch individuals capable of making relatively long feeding migrations, the prevalence of metacercariae in this section of the reservoir was 22.73%. In rarely migrating coastal groups of perch fingerlings, the prevalence of metacercariae ranged from 3.57% to 96.47% at different sites of the Volga Reach. A wider spread of rossicotremosis was observed in the Gorky Reservoir. Even in pelagic trawl catches from the lake-like section of this reservoir, the prevalence of metacercariae in perch fingerlings was found to be between 5.00% and 47.83%. A very large focus of rossicotremosis in the Gorky Reservoir formed upstream the lake-like expansion, in the area affected by heated waste waters from the Kostroma State District Power Plant, where only juvenile specimens of zander, Sander lucioperca (Linnaeus, 1758), were insignificantly infected – 0.49%. At the same time, the prevalence of metacercariae in the integrated sample of perch individuals of various ages was 92.31%, while in the integrated sample of different-aged ruff, Gymnocephalus cernuus (Linnaeus, 1758), it reached 100%. The clearly pronounced localization of rossicotremosis foci may be attributed to the relatively high thermophilic nature of the trematode A. donicus, the limited circle of its second intermediate hosts, and their relatively low population densities. In addition to Percidae species, monitoring of the common parasite fauna, even in the rather large Rybinsk Reservoir, revealed A. donicus metacercariae only in one adult specimen of pike, Esox lucius (Linnaeus, 1758), and one yearling specimen of the freshwater tubenose goby, Proterorhinus semilunaris (Heckel, 1937).

FIRST RECORD OF THE VERMICULATED SAILFIN CATFISH PTERYGOPLICHTHYS DISJUNCTIVUS (WEBER, 1991) (ACTINOPTERYGII: SILURIFORMES: LORICARIIDAE) IN THE DNIESTER RIVER BASIN - Filipenko S.I., Mustya M.V.- A single specimen of the vermiculated sailfin catfish Pterygoplichthys disjunctivus (Weber, 1991), caught in September 2025 in the Kuchurhan Reservoir–cooling pond of the Moldavskaya Thermal Power Plant, represents the first record of this alien species in the inland waters of Moldova and Pridnestrovie. The fish had 38.5 cm in total length and a weighed of 585 g. Its condition factor (2.062) indicates favorable environmental conditions in the reservoir for this species. The most probable introduction pathway is either accidental or intentional release by aquariumists.

NEW AND RARE SPECIES OF PLANTS – INVADERS IN THE REPUBLIC OF BURYATIA - Chimitov D.G., Borisova N.G., Starkov A.I. - The Republic of Buryatia is located within the influence zone of Lake Baikal, the largest freshwater lake in the world, which underscores the importance of conserving the region's biodiversity. This study presents new data on vascular plant invader species in Buryatia: two species are recorded for the first time, and three new localities of rare species have been identified also. The invasive potential of these species was assessed through distribution modeling using bioclimatic variables, analysis of biological traits, and documented invasion cases. The results indicate a high invasive potential of Cuscuta chinensis and Solanum nigrum, demanding an increased attention from conservation authorities.

THE INVASION OF BRANCHIURA SOWERBYI BEDDARD, 1892 (OLIGOCHAETA) OCCURS BY ONE GENETIC GROUP OF THE SPECIES - Baturina M.A., Ivicheva K.N., Golubev M.A., Filonenko I.V., Velegzhaninov I.O. - The freshwater oligochaete Branchiura sowerbyi (Beddard, 1892) is an alien species exhibiting rapid range expansion. It has been documented across Africa, Asia, North America, and Europe. In Russia, the species has been found since 2014. In the presented study, the molecular genetic data of B. sowerbyi individuals were obtained for the first time from water bodies in Russia and their genetic diversity was compared with published data from other infested and native countries to infer potential invasion pathways. Analysis of the cytochrome c oxidase subunit I (cox1) gene sequence revealed three related genetic groups within the species. Only one of these groups, including specimens from Russia, is distributed worldwide. The appearance of the species in Russia is likely the result of recent penetration as the result of invasion from the Indo-Chinese region and from already inhabited European countries with the Black Sea basin being a probable invasion corridor.

HOW DO INFLORESCENCES OF LUPINUS POLYPHYLLUS (FABACEAE) RE-ESTABLISH THEIR POSITION AFTER ARTIFICIAL BENDING? - Glagoleva N. S., Volkova P. A., Medvedev A. A., Yavorskiy M. R. - The correct position of the inflorescence is vital for pollination success. Many plants have physiological reorientation mechanisms based on the effects of the hormone auxin, which is secreted in apical meristems and induces negative gravitropism. The younger the inflorescence is, the more important it is to restore its vertical position in the fastest possible way to maximize pollination success. Thus, we investigated the effect of the absence of inflorescence’s apical part and inflorescence age on its reorientation and position of bending point. As an object of investigation, the invasive Lupinus polyphyllus was chosen, since the position of the flowers along the axis makes the plant convenient for manipulation. Removal of the apex does not influence the restoration of orientation relative to the ground. Younger inflorescence tends to have a greater part of them reoriented. The reoriented part of the inflorescence mainly contained unopened or partly opened flowers at the moment of the initial bending by the experimenters.

THE INVASION OF ERIGERON CANADENSIS L. (ASTERACEAE: ASTEREAE): A SUBSTANTIAL THREAT TO PLANT DIVERSITY AND COMMUNITY STABILITY IN NATURALLY RESTORED SECONDARY BARE LANDS - Wu B.D., Qi Y., Chen Z.Y., He Z.Q., Wang C.Y., Liu L.Y. - The ecosystem of naturally recovered secondary bare land (NRSBL) is highly vulnerable to external interference. Alien invasive plants can exert notable impacts on the restoration of indigenous plant communities. This study aimed to investigate the effects of a global alien invasive plant of Erigeron canadensis L. with different invasion degrees (including uninvaded condition, the low invaded with the relative abundance of E. canadensis < 35%, and high invaded with the relative abundance of E. canadensis > 75%) on the indigenous plant communities in NRSBL in the subtropical monsoon climate zone of Zhenxiong, Zhaotong, Yunnan, China. The results showed that E. canadensis invasion significantly decreased plant species diversity and community stability, with a highly significant negative correlation between E. canadensis relative abundance and these two types of indices. Low invasion of E. canadensis caused mild disturbance on the species diversity and no significant disruption (even potential promotion) on the community stability, while high invasion of E. canadensis induced moderate to severe disturbances on the two indices. This study provides a strong theoretical support for the early warning and control of invasive plants in NRSBL.

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