Volume 104, Nº 1 (2025)

The present study is based on oribatid mite material collected from four locations in Guatemala. A list of 48 species belonging to 38 genera and 28 families is presented. Of these, 39 species, 26 genera and 13 families are recorded from Guatemala for the first time; and two species, one genus and one family are recorded from the Neotropical region for the first time. In addition, three new species are described: Hermanniella oblonga Ermilov sp. n. (Hermanniellidae), Protoribates silvaticus Ermilov sp. n. (Haplozetidae) and Pergalumna guatemalaensis Ermilov sp. n. (Galumnidae).

Changes in the species composition and numbers of diplopods in the boxwood area of a yew-boxwood grove resulting from an invasion of the boxwood moth were studied. Data before and several years after the invasion were compared. The disappearance or reduced numbers of some species, as well as changes in the dominant and subdominant structures were revealed in the study area. Statistical analyses showed both a significant decrease in alpha diversity and changes in beta diversity.

Adaptive features of the skull were compared with the resource of soil macrofauna in populations of three monomorphic chromosomal races of the common shrew from different ecosystems. In the severe climatic conditions of the shrubby tundra of the Vorkuta area (67°29ʹ N), with extremely low abundance of large oligochaetes (earthworms), the population of the Serov race is characterized by small sizes of the skull and brain capsule, a relatively short arm of the temporal muscle strength, a weak jaw compression force therefore being likely. In the tundra ecosystem, McNab’s “resource rule” is confirmed while Bergman’s rule (optimization of metabolism by a relative reduction of the body surface area) is violated. In the severe climatic conditions of the mountainous areas of the northern taiga in the northern Urals (62°05ʹ N, 520– 650 m above sea level), with high numbers of earthworms, the Serov race is characterized by large sizes of both skull and brain capsule, a lengthened temporal muscle force arm, therefore, increased temporal muscle mass and jaw compression force thus being likely and corresponding to McNab’s “resource rule” and Bergman’s rule. In spruce-broadleaved forests between the Upper Volga River area and Oka River (55°44ʹ N) with high abundance of earthworms, small sizes of the skull and brain capsule are characteristic of the Moscow race, the force of jaw compression being increased by an increase in the arm of temporal muscle strength. Under the best climatic conditions, a decreased size of the Moscow race is consistent with Bergman’s rule and violates McNabb’s “resource rule”. The results of the study show that climatic conditions are capable of directly affecting the body size of shrews, not only indirectly through the productivity of the environment, thus confirming Bergman’s rule.

Using anatomical and histological methods, we studied the norm and pathological changes in the skin of 12 Baikal seals of different ages (Pusa sibirica) (alopecia, ulcers, scars, etc.). Similar changes are usually observed in many seals appearing on coastal rookeries. Norm: the skin has a folded epidermis on the body and flippers. Hyperkeratosis of the epithelium is noted. No border between the papillary and reticular layers of the dermis is expressed. The papillary layer is formed by thin bundles of collagen fibers, the reticular layer by thick bundles of collagen fibers. In the reticular layer of the skin of the body, there are powerful, numerous bundles of smooth muscles. The dermis of the skin of the flippers is thinner in comparison with the dermis of the skin of the body. In the skin of the body, the sebaceous glands are small and multi-lobed; each hair bundle is usually surrounded by two such glands. The lower secretory sections of the apocrine sweat glands are weakly convoluted and tubular, being located in the deep layers of the reticular dermis and in the adipose tissue separately from the hair follicles and next to the network of blood vessels. Their narrow excretory ducts open into the funnel of the hair at the level of its upper third. In the skin of the flippers, large convoluted apocrine glands are located at the level of the lower sections of the bulbs of the guard hairs, elongated polymorphic excretory ducts of the sebaceous glands open into the hair bags. Morphophysiological adaptations of the skin of seals, contributing to the improvement of its hydrodynamic, thermoregulatory and sun-protective properties, are discussed. Pathology: two main complexes of skin pathologies in seals have been identified: (1) koilocytosis, subepidermal inflammation (the infiltrate is represented by lymphocytes with a small admixture of histiocytes), lymphocyte exocytosis in hair follicles with spongiosis; (2) formation of a subepidermal blister with neutrophilic infiltration in the papillary layer of the dermis. These pathologies may be associated with global warming and changes in the ice regime of Lake Baikal, which may have led to the development of immune inflammatory processes in the skin. The effect of an unknown viral pathogen that caused koilocytosis in seals cannot be ruled out.

A new hoverfly species of the genus Eumerus Meigen 1822 is described and illustrated from southeastern Turkmenistan: Eumerus glabropterus Barkalov sp. n. The new species is close to species of the strigatus group, which is outlined by the following taxonomic characters: eyes of male touching on frons, legs with neither obvious outgrowths nor modifications, hind tibia in basal third with small, pressed, black spinules, abdomen is completely black (sometimes with a yellow hind rim of sternum IV), almost always with 3 pairs of gray spots. The new species is easily distinguished from all representatives of this and other species groups by the unique structure of the male genitalia, and, in addition, from the most similar one, Eumerus acuticornis Sack 1933, by a narrower frons, the absence of long hairs from the lower surface of the hind femora, and a gentle notch at the posterior edge of sternite IV.