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Vol 104, No 6 (2025)
ARTICLES
New and rare species of microturbellarians of the genus Opisthocystis sekera, 1911 (Platyhelminthes, Kalyptorhynchia, Polycystididae) from Lake Baikal
Abstract
Descriptions of four new species of the genus Opisthocystis Sekera, 1911 are given: Opisthocystis zaytsevae Krivorotkin et Timoshkin sp. n., Opisthocystis strictostylus Krivorotkin et Timoshkin sp. n., Opisthocystis sekeri Krivorotkin et Timoshkin sp. n. and Opisthocystis tenuistylus Krivorotkin et Timoshkin sp. n., all of them endemic to Lake Baikal. The former three species were found in the coastal zone of the lake: O. zaytsevae: in the shallow waters of Bolshoy Ushkany Island; O. strictostylus: in the shallow waters of Ayaya Bay (northern basin) and opposite the village of Khuzhir (Olkhon Island, Maloye More Strait); O. sekeri: in the shallow waters of Onokochanskaya Bay (northern basin); O. tenuistylus was found on the underwater Akademichesky Ridge at a depth of about 350 m. Illustrated descriptions, differential diagnoses, brief information on their distribution and ecology are provided for all new species. New extensive information on the morphology and zoogeography of three rare and poorly studied endemic Baikal species of the same genus is provided: Opisthocystis multifidus (Nasonov, 1935), Opisthocystis octopropagostylus Lukhnev et Timoshkin, 2014, and Opisthocystis cf. umylinae Timoshkin, 2010. Brief illustrated descriptions and generalized information on their distribution are provided for all species. Revision of the taxonomic status of five Baikal species is proposed: Opisthocystis bilobatus Nasonov, 1935, Opisthocystis bicurvatus Nasonov, 1935 Opisthocystis campanulatus Nasonov, 1935, Opisthocystis irregularis Nasonov, 1935 and Opisthocystis trifida Nasonov, 1935. These species were described very briefly, and the drawings were very schematic. Based on the poor descriptions and schematic drawings, their reliable identification is impossible. In this regard, we are compelled to assign the status of nomen nudum to the above species of N. V. Nasonov.
Zoologičeskij žurnal. 2025;104(6):3-25
3-25
Features of the biological state of the smooth scallop (Flexopecten glaber (Linnaeus, 1758), Bivalvia, Pectinidae) in a sand mining area in the Black Sea
Abstract
Using the Flexopecten glaber scallop population in Donuzlav Bay as an example, the main biological indicators of specimens sampled synchronously in two test areas were examined and compared: (1) a zone under the direct influence of sand mining, and (2) an intact zone with a natural sedimentation process. The sea scallop was found in Donuzlav Bay at depths ranging from 0.5 to 17 m, but its distribution was discontinuous and uneven. The main clusters of F. glaber were concentrated at depths of 2–3 m, where the density of scallops in some areas of the intact zone reached 12 specimens per sq. m. In the distribution zone of turbidity from sand washing, the density of scallops reached 6 specimens per sq. m. It scallops from both test samples, the age structure of settlements, the average values of size-weight characteristics and the stages of gonad formation were shown to be quite close. However, in scallops from the conditionally intact zone, the average gonad mass was twice as large, and the gonadal index was 1.5 times higher. The scallops of the unaffected zone had the gonads that were not only larger, but also brighter and more varied in color. These and other characteristics studied indicate that scallops in the turbidity zone affected by sand mining were physiologically suppressed. Despite some signs of improvement in the status of the F. glaber population in the Black Sea, the need to maintain conservation measures for the species and to strengthen these measures in areas with increased anthropogenic influence is highlighted.
Zoologičeskij žurnal. 2025;104(6):26-35
26-35
Two new species of bristletails of the genus Pedetontus silvestri, 1911 (Microcoryphia, Machilidae) from the Russian Far East
Abstract
The relatively large Indo-Malayan-Holarctic genus Pedetontus Silvestri, 1911 has so far included 33 described species. The genus has two subgenera: the nominative, Pedetontus s. str., with seven species (6 from North America and one from Kamchatka) and Verhoeffilis Paclt, 1972, with 26 species (three species from North America, 12 from the southeastern Palaearctic and 11 from the Indo-Malayan Region). Both subgenera are distinguished by the presence of two pairs of retractable vesicles on abdominal segments II–VI or II–V, respectively. Two new species of the latter subgenus are described from the Primorsky Territory of the Russian Federation: P. furuhjelmi sp. n., from Furugelm Island, and P. nigrus sp. n., from near Ussuriysk. Both these new species are very close to P. ussuriensis Kaplin, 1980, widespread in the Primorsky Territory, and P. silvestrii Mendes, 1993, from North Korea, but differ well in body length, the relative length of the antennae, the structure of the antennal flagella, the compound eyes, the paired ocelli, the maxillary and labial palps, the sternites, styli and coxites of abdominal segment IX, as well as by the chaetotaxy of the legs and urocoxites IX, and the ovipositor.
Zoologičeskij žurnal. 2025;104(6):36-46
36-46
On the leaf beetle genus longitarsus berthold, 1827 from the caucasus, with the description of a new species (coleoptera, chrysomelidae, galerucinae, alticini)
Abstract
A new species of leaf beetle, Longitarsus kovali Romantsov sp. n., is described from Abkhazia. A new key to distinguish the new and the closely related species L. fulgens (Foudras, 1860), L. languidus Kutschera, 1863, L. medvedevi Shapiro, 1956 and L. tristis Weise, 1888 is proposed. Syntypes of L. ratshensis Khnzorian, 1962 are revised, the lectotype is designated, photographs of the adult habitus in dorsal view and the genitals for both sexes of this species are provided for the first time. Differences between this species and the closely related L. ledouxi Doguet, 1979 are presented. Longitarsus medvedevi is recorded from Kazakhstan for the first time.
Zoologičeskij žurnal. 2025;104(6):47-58
47-58
Two new species of the gelechiid moth genus Gelechia Hübner [1825] (Lepidoptera, Gelechiidae) from Malaysia and the Philippines
Abstract
Two new species of gelechiid moths from the genus Gelechia Hübner are described: G. serratocornuta sp. n. from both Borneo, Malaysia and Mindanao Island, Philippines, and G. bifurcata sp. n. from Mindanao alone. The male genitalia of the new species have the uncus with either a single bifurcated projection or with two projections, these making them distinguished from the other species of this genus with known male genitalia.
Zoologičeskij žurnal. 2025;104(6):59-64
59-64
Additional data on the summer-autumn diet of the black grouse (Lyrurus tetrix, Galliformes, Tetraonidae) in the southern forest zone of the Russian plain
Abstract
The composition of the summer-autumn diet of the Black grouse (Lyrurus tetrix) in the south of the forest zone ranging from Poland to the Urals has been thoroughly studied, but questions about the actual ratios of food consumed remain open. The feeding strategy of the birds in late summer and early autumn is also unknown. To partially fill in these gaps, we analyzed the craw contents of the birds hunted in the southern taiga (n = 22) and in coniferous-broadleaf forests (n = 24) in July–October 1987–2023. The plant genera Trifolium, Hieracium, Rumex, Sonchus and other herbs growing in a grassland or at forest edges formed the main part of the diet (% wet weight) in both black grouse populations studied. The basis of animal food was also represented by insects of open landscapes: grasshoppers (Acrididae) and leaf beetles (Chrysomelidae). The main diet components (75–76% wet weight) constituted only ~20% of the total food lists, indicating something close to oligophagy: long food lists with only a few food items being important and most food species found to be consumed in very small quantities. The relations between the estimates of wet weight (%) and the occurrence of food were expectedly weak, but large weights could correspond to either low or high occurrence estimates; this situation should make comparisons across literary sources difficult. The total absence of any fragments of heather shrubs (Ericaceae) in the diet of both populations along with the absence of any berries in the nutrition of the southern taiga individuals were unexpected. In contrast to other L. tetrix populations from the southern forests of the Russian Plain, the attention the study birds paid to food objects proved to be dispersed across many food species, possibly owing to the long time span of our datasets. Nevertheless, the most probable reason for all habits of the Black grouse noted seems to lie in a decreased human agricultural activity (grain growing and haymaking) and ousting the birds from forest-meadow edges by people (via recreation and gathering berries and mushrooms) deep inside grassland habitats, where the forage base for black grouses has apparently been much more variable and less predictable than under the discontinuous forest canopy more familiar to the birds.
Zoologičeskij žurnal. 2025;104(6):65-88
65-88
SLEEP CHARACTERISTICS AS A COMPARATIVE INDICATOR OF VIGILANCE IN REINDEER POPULATIONS (RANGIFER TARANDUS)
Abstract
During the rest periods of reindeers’ daytime we recorded “looking around”, “waking”, “dozing” and “sleeping”. Observations were made through a telescope from a distance sufficient to avoid disturbing the animals. We studied wild reindeer from the Snøhetta Mountains, Norway and the Spitsbergen Archipelago populations, feral reindeer from the Forelhogna Mountains Norway, the Wrangel Island populations and domestic reindeer from the Chukotka Peninsula. Reindeer from the Snøhetta Mountains, the Spitsbergen Archipelago and the Forelhogna Mountains populations were studied in winter to early spring (during the snowy period). Reindeer from the Wrangel Island and the Chukotka Peninsula were observed in June to July, during the snowless period. The duration of individual sleep episodes in the wild Snøhetta reindeer averaged about 4 minutes, vs 2 to 3 minutes in domestic and feral reindeer. Highly reliable differences in sleep episodes were found between the Snøhetta Mountains reindeer and other populations, except for the Forelhogna reindeer, whose differences, together with the Snøhetta Mountains reindeer, were only close to the reliable level (p = 0.076). The Wild Spitsbergen archipelago reindeer failed to differ from both the domestic Chukotka Peninsula reindeer and the feral Wrangel Island reindeer. For comparison, we used our data on the flight distance of reindeer when approached by humans in the same populations. Flight distances and the duration of sleep episodes in the Snøhetta Mountains reindeer differ from those all other populations, and the characteristics of the wild Spitsbergen archipelago reindeer were close to those of the domestic Chukotka Peninsula reindeer. Domestic reindeer of the Chukotka Peninsula were studied in the summer, when reindeer gather in dense masses to rest (herd size more than 3,000). Neighboring reindeer at rest often interfere with each other.
Zoologičeskij žurnal. 2025;104(6):89-92
89-92
APICAL ELONGATION OF MOLARS IN THE WATER VOLE (ARVICOLA AMPHIBIUS (L.), RODENTIA, ARVICOLINAE)
Abstract
Dental anomalies of the lower and upper jaws caused by the proliferation of the apical parts of the molars were found in water voles from a laboratory colony. Such a molar phenotype is observed in several representatives of the subfamily Arvicolinae with a constant growth of cheek teeth. In the Water vole, apical elongation of the upper jaw molars was found in 48.4% individuals, and of the lower jaw in 53% individuals (n = 589). The upper molars penetrate the cranial cavity of the animals, while the lower molars form bone growths on the buccal side of the jaw. Elongation of the molars on the lower and upper jaws occurs interrelatedly, as evidenced by the positive correlation between these features (r = 0.35). Ingrowth of molars into the cranial cavity is associated with the sex of the animals. In all age classes, the proportion of females with molar invasion into the skull is higher than that of males. The frequency of detection of dental anomalies is the highest at the age of 1–2.5 years. Positive correlations between the presence of a dental anomaly in siblings or in parents and offspring indicate the hereditary determination of the traits. The growth of the apical parts of the molars on the upper or lower jaw is associated with a decrease in the reproductive performance of females and does not affect the reproductive ability of males.
Zoologičeskij žurnal. 2025;104(6):93-100
93-100
Influence of weather conditions on the activity of the common vole (MICROTUS ARVALIS PALLAS, 1778, CRICETIDAE, RODENTIA)
Abstract
A detailed understanding of how weather influences the behavior of small mammals enhances our knowledge of species ecology and improves the interpretation of field study results. While the effect of weather on small mammal activity has long been recognized, research findings remain inconsistent, varying by species, season, and habitat. In the case of the Common vole, only a limited number of studies have examined this relationship, often focusing on a narrow range of weather parameters and yielding contradictory conclusions. This study aimed to investigate the influence of multiple weather factors on the activity (mainly nocturnal) of common voles in an open habitat during summer. To gather a sufficiently large dataset, an original technique for assessing small mammal activity by the footprint presence in systematically placed tracking devices was used. The study was conducted over one month across a 9‑hectare area, where 961 tracking stations – each consisting of a plastic bottle, a tracking cartridge with waterproof ink, and bait – were deployed. The Common vole was confirmed as the dominant small mammal species in the study area through intensive trapping in the central part of the experimental plot. Over 10,571 device inspections and 6,910 vole visits were recorded. Weather data were recorded using an automatic weather station. The results demonstrated that wind, rain, higher temperatures, and increased humidity all contributed to greater activity in common voles. In contrast, elevated illumination levels reduced movement intensity. The methodology proved effective for obtaining large datasets to assess small mammal activity in monospecific communities.
Zoologičeskij žurnal. 2025;104(6):101-107
101-107
MICROHABITAT PREFERENCES OF SOME RODENT SPECIES IN A COMMUNITY LIVING IN THE HIGH-MONTANE ZONE OF THE REPUBLIC OF DAGESTAN
Abstract
The microhabitat distribution, the position of spatial niches and the abundance of eight mouse-like rodent species living in the high-montane zone of the Republic of Dagestan were assessed. Twenty environmental parameters were selected, 16 of which discriminated interspecific differences significantly. The distribution of rodents relative to environmental parameters was shown to make the greatest contribution to interspecific differences and species preferences for the habitats and microhabitats of all rodents. The rodent species in the study area can be divided into four groups (guilds): forest species and open-space species, rocky-gravel species and near-water species. The results of pairwise comparisons of the spatial niches of the rodent species considered revealed low values of their overlap.
Zoologičeskij žurnal. 2025;104(6):108-117
108-117
ХРОНИКА И ИНФОРМАЦИЯ
(RUSSIA, KALUGA, 7–12 OCTOBER 2024)
Zoologičeskij žurnal. 2025;104(6):118-120
118-120