Zoological Institute

The fish species Cottus kuznetzovi was described by L.S. Berg in 1903 from the Lena River system. However, two years after its description, Berg synonymized this sculpin with the widely distributed species C. poecilopus Heckel, 1837. It remained a junior synonym until 2009, when this species was redescribed and revalidated. Despite this, some researchers continue to doubt the validity of C. kuznetzovi. The authors obtained new materials from the Arctic region of Eastern Siberia and the upper reaches of the Lena River. This made it possible to apply molecular genetic methods to resolve issues related to the taxonomic status and genetic differentiation of C. kuznetzovi, and also enabled the discovery of this species in new areas. As a result of the analysis of the nucleotide sequences of the mtDNA control region (CR) and the cytochrome b gene (cytb), individuals of the species C. kuznetzovi were identified in the upper reaches of the Lena River, as well as in the Aldan, Indigirka, and Yana river systems. The average p-distance (CR) between different populations was 0.97 ± 0.29%. The presented results indicate a strong genetic isolation of this species from all closely related sculpins. The average p-distances between C. kuznezovi and closely related species of the group “Cottus poecilopus” ranged from 2.50 ± 0.47% to 3.95 ± 0.63% for CR marker, and from 1.50 ± 0.35% to 7.95 ± 0.81% for cytb marker. The validity of this species has been reliably established.

Craniological traits were compared between hatchery-raised and wild-caught juveniles in the Eizenam brown trout Salmo trutta ezenami Berg, 1948 and the Atlantic salmon S. salar Linnaeus, 1758. Six out of ten meristic traits under study were found to differ significantly between the wild and cultivated samples in either species. Among 39 morphometric trait indices, 22 differed significantly between the S. trutta ezenami samples and 14, between the S. salar samples. Differences in meristic traits between the wild and hatchery samples of the same species were greater than differences between the two species. The differences were most likely determined by differences in environmental conditions, although an effect of size variation could not be excluded completely (cultivated fish were somewhat smaller than wild fish). High plasticity of craniological traits should be taken into account when studying the taxonomy and evolution of salmonids.

Abstract Once nearly eradicated from Europe, grey wolves ( Canis lupus ) have recently undergone a remarkable demographic recovery, but their long-term survival remains precarious. By analyzing 1,001 genomes, we uncover a mosaic of distinct evolutionary lineages, not a single recovering population. Northern populations exhibit Asian wolf ancestry, while southern populations preserve ancient Holocene lineages, with dog introgression varying by region. Isolated wolves from the Scandinavian, Italian, and Iberian peninsulas harbored particularly high levels of inbreeding and fixed deleterious mutations. Signatures of genome erosion were widespread across Europe, with many populations falling well short of the minimum size recommended for long-term survival. Our study reveals the complex tapestry of wolf ancestry and variation across Europe, which calls for nuanced, regional conservation plans founded in genetic monitoring.

The article is a review of systematic studies using osteological characters for reconstructing the phylogeny and constructing the system of bony fishes from the time of Berg’s book Classification of Fishes to the present day. The properties of skeleton related to the nuclear gene induction are reviewed. The induction role of the Hox cluster genes in the sequence of appearance of the anlages of dorsal and anal fin rays and in transformation of the caudal f in structure are discussed. The effects of nuclear genes on the formation of jaws, gill arches, and pectoral fin of f ishes are demonstrated. The conflict between morphologists and molecular biologists regarding the problem of phylogeny reconstruction and systematics is discussed. Using the example of the taxonomic position of the genus Bathylutichthys (Cottoidei), it is shown that information about even one osteological character can fundamentally change the understanding of the phylogeny of the suborder. The conclusion drawn is that morphological and molecular results should be integrated in order to obtain phylogenetic reconstructions and construct a system.

The Siberian moth, Dendrolimus sibiricus Tschetverikov, is one of the most destructive conifer pests in Northern Asia, causing severe ecological and economic losses. In Russia, its range overlaps with that of the closely related pine-tree lappet Dendrolimus pini (L.), and this raises the potential for hybridization and complicates accurate identification, particularly in the context of the potential westward expansion of D. sibiricus. Here, we present the first comprehensive morphometric analysis of male genitalia aimed at distinguishing these two major forest pests and their hybrids. The study was based on D. sibiricus and D. pini specimens collected during the last 130 years (1894-2024) across Europe and Asia, including their hybrids reared indoors by crossing D. pini females with D. sibiricus males in 1956 and preserved in the collection of the Zoological Institute of the Russian Academy of Sciences (St. Petersburg, Russia). Overall, 70 permanent genitalia slides were prepared (33 D. sibiricus, 33 D. pini, and 4 hybrids), and the following genital structures were measured: valva and harpe length, aedeagus width and length, and cornuti length. Dendrolimus sibiricus had significantly larger genital structures compared to D. pini: 74% longer harpe, 32% longer valva, and a 28% wider and longer aedeagus. In contrast, in D. sibiricus cornuti were 21% shorter than in D. pini. Hybrids displayed intermediate values for valva, harpe, and aedeagus lengths, and for these parameters, they significantly differed from both parental species. The following diagnostic indices were suggested to distinguish between the two species and their hybrids: Harpe Length/Valva Length Index (HL/VL) and Cornuti Length/Aedeagus Length Index (CL/AL). Decision-tree analysis identified HL/VL as the strongest predictor for separating the parental species and the Combined Genital Proportion Index (CGPI), which integrates harpe, valva, aedeagus, and cornuti lengths, as the strongest predictor for identifying hybrids. The morphometric criteria developed here have practical applications for monitoring programs and quarantine diagnostics, particularly in sympatric zones and regions at risk of D. sibiricus expansion.

Analyses of morphological characters of the scaly-headed gunnels reveal that Russian waters are inhabited by only one species from this group, Pholis crassispina, while Ph. nebulosa is absent. The article also provides values of important diagnostic characters for both species and clarifies the range of Ph. crassispina in Russian waters.

Cardinium endosymbionts are obligate intracellular bacteria found in a wide range of invertebrate hosts. In this study, we generated ten new Cardinium genomes from plant-parasitic nematodes of the genera Amplimerlinius, Bursaphelenchus, Cactodera, Ditylenchus, Globodera, Meloidoderita, and Rotylenchus, revealing their broad ecological and phylogenetic distribution. Using an expanded set of genes, we clarified the relationship between previously defined Cardinium groups B and F from nematodes, showing that they are closely related and likely share a single evolutionary origin within nematode-associated Cardinium. Among the newly assembled Cardinium genomes obtained in this study, two genomes originating from strains associated with wood-inhabiting Bursaphelenchus species exhibited remarkable genome reduction, with estimated sizes of approximately 695 kb. Functional annotation of Cardinium genomes indicated an absence of or a reduction in several central metabolic pathways, including the biotin biosynthetic pathway. A complete biotin pathway was found only in D. weischeri, and this pathway is only partially encoded in Cactodera sp. The polA gene, which encodes DNA polymerase I, showed partial loss in several Cardinium strains. Phylogenetic and comparative genomic analyses provided strong evidence that several carbohydrate, glycerophospholipid, and biotin metabolism genes in these endosymbionts have been acquired through horizontal gene transfer. Future research that integrates high-quality genome assemblies with functional analyses of host–symbiont interactions will be essential to elucidate how metabolic dependency, genome reduction, and horizontal gene transfer collectively shape the evolution and ecological diversification of Cardinium across nematode hosts.

Bovichtus veneris Sauvage, 1879 is a poorly studied species endemic to St Paul Island in the Indian Ocean. External morphology, teeth, axial skeleton and seismosensory system of three type specimens from the Muséum national d’histoire naturelle in Paris and one specimen from the collection of the Zoological Institute of the Russian Academy of Sciences, St Petersburg, were studied. A scheme of the seismosensory system of B. veneris is given. The investigated characters of B. veneris are compared with those of other species of the genus Bovichtus Valenciennes, 1832. The following diagnostic characters of B. veneris are established: snout length is less than the diameter of the eye and less than 25% of head length; the first predorsal distance is 1.2–1.5 times the interpelvic distance; caudal peduncle is 11.0–11.4%, opercular spine is 14.4–17.8% of standard length; outer teeth on the upper jaw are slightly enlarged; coloration is monotonous, without pronounced spots and saddles.

Purpose: to fi nd the duration of hypolipidemic effect after the course of intravenous laser therapy in patients with coronary artery disease (CAD) and lipid metabolism disorders resistant to hypolipidemic pharmacotherapy. Patients and methods. 40 patients with CAD and lipid metabolism disorders (LMD) resistant to hypolipidemic drugs were enrolled in the trial. Patients were divided into two comparable groups depending on the curative technique: 20 patients from Group 1 (main group) had intravenous laser blood irradiation (ILBI) and supportive medicamentous therapy (SMT). 20 patients from Group 2 (control group) had only SMT. Results and discussion. Initially, patients in both groups had LMD signs despite of hypolipidemic drug therapy: elevated levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), atherogenic index (AI), and reduced high-density lipoprotein cholesterol (HDL-C) compared to normal values. Baseline values in both groups were statistically insignifi cant for TC, HDL-C, LDL-C and AI levels which indicated comparability between the groups. The study results demonstrated that patients in the main lasered group with ILBI course demonstrated much better hypolipidemic effect in 1 and 3 months after the treatment compared to baseline values: signifi cant reduction in TC by 19.1 % and 16.1 %, respectively; signifi cant reduction in LDL-C by 24.1 % and 21.8 %, respectively; signifi cant reduction in AI by 33.7 % and 29.1 %, respectively. Four months after the ILBI course, hypolipidemic effect became signifi cantly less evident, and lipid profi le indicators in the main group returned to baseline levels, except for total cholesterol. Therefore, in 4 months after ILBI course, patients require a repeated laser therapy course. The controls throughout the observation period had no signifi cant positive dynamics compared to baseline values. Conclusion . In patients with CAD and LMD resistant to hypolipidemic drugs, ILBI therapy corrects LMD. It has been demonstrated by the signifi cant reduction in TC, LDL-C, and AI levels, as well as by increased HDL-C level, although lipid profi le parameters did not reach their normal or target values. The obtained positive effect persisted for 3 months after the course of laser therapy. After that, ILBI positive effect gradually went down, except the total cholesterol. That is why, in four months patients require a repeat course of laser therapy. To achieve a full hypolipidemic effect in this category of patient, it is necessary to develop and incorporate other non-drug curative techniques.