Краткие сообщения

The object of our study of the functional activity of the body's immune reactions over a long period (2021–2024) was Pelophylax ridibundus in the reservoir of an urbanized territory (Silikatnoye Lake, Nizhny Novgorod) infected with Hepatozoon spp. A hydrochemical analysis of the habitat of P. ridibundus was done. Intraerythrocyte parasites were accounted for with the calculation of the extent and intensity of invasion and abundance of hemoparasites.

The results of our study of age and growth of the Eastern slowworm (Anguis colchica) in two localities in the east of the Lesser Caucasus are presented. 33 individuals (18 males and 15 females) from the vicinity of Stepanavan town (Lori Marz, Armenia) were studied. A sample from the vicinity of Zanavi village (Borjomi municipality, Samtskhe-Javakheti region, Georgia) contained 19 specimens (6 males and 13 females). The body length of captured animals was measured and the tip of the tail was clipped.

The paper presents a comparative analysis of the growth rates and characteristics of 10 lizard species from the genus Darevskia (D. armeniaca, D. arribasi, D. brauneri, D. caucasica, D. daghestanica, D. derjugini, D. mixta, D. pontica, D. raddei, and D. valentini) in laboratory conditions. It has been shown that lizards from different species complexes, but originating from close localities, are characterized by similar growth features.

15 species of ixodid ticks (Ixodida) and 2 ones of gamasid mites (Mesostigmata) were identified in the true lizards (Lacertidae) of the Caucasus harbor according to our own and literature data. Of which one species of ixodid and both species of gamasid ticks are specific to reptiles. The core of the fauna of ixodid ticks is formed by species of the genus Haemaphysalis. The largest number of ixodid tick genera and species are associated with lizards of the genus Lacerta.

The development of a technology for hypothermic preservation of amphibian oocytes is one of the urgent tasks for cryobiology. The previously proposed method of “dry” hypothermic preservation in small sealed containers allowed us to increase the duration of refrigerated storage of unfertilized oocytes of the grass frog Rana temporaria up to 7 days (fertilization 40%; hatching 20%).

The study focuses on demographic characteristics of amphibians in a megacity environment, using Moscow City as a case study. The relevance of our research is driven by the impact of the urban environment on ecosystems. In Moscow City, home to over 13 million people, the urban infrastructure affects the natural habitats of amphibians. The study primarily examines the common toad (Bufo bufo) and common frog (Rana temporaria).

Our study of the Phrynocephalus mystaceus mystaceus (Pallas, 1776) intrapopulation group on the Sarykum sand massif was carried out during the breeding seasons (1^st ten days of May) in 2021 – 2024. In this part of the habitat, the species forms local groups with a very high population density (from 72.9 to 95.7 ind. / ha). Apparently, this is due to the island position of the population on the Sarykum.

Our sex ratio analysis of mature individuals in populations of 5 lizard species, genus Eremias (Lacertidae) and genus Phrynocephalus (Agamidae), during the breeding season has shown that males predominate in the genus Eremias in most cases, while females predominate in the genus Phrynocephalus. This fact is confirmed by data collected by other researchers on 14 more species of the indicated genera. The authors believe that this difference is due to some ecological features of the noted systematic groups.

The article provides information on the distribution of Zamenis hohenackeri in the North Caucasus, mainly in Dagestan and the adjacent territory of Chechnya, and analyzes literature data on the distribution of the species in the republics of Ingushetia and North Ossetia-Alania. Based on the literature and original data of the authors, as well as collection specimens, the most complete map and cadastre of the species findings in the North Caucasus have been compiled, which include 43 locations of the species.

Natural polyploidy cases in reptiles are analyzed. They are characterized by spontaneous autotriploidy, non-hybrid mixoploidy (2/3n), hybrid biotypes (2 and 3n), polyploid species, and tetraploid hybrids obtained from crossing triploids with diploids. Polyploid species are always triploid and parthenogenetic. Neither gynogenesis nor various types of hemiclonal inheritance have been observed among them. In all cases studied, reticulate speciation in reptiles stops at the stage associated with tetraploidy.