Zoologičeskij žurnal

The first record of a species from the order Zoantharia in the Black Sea is given. Zoantharians were successfully reared from planktonic larvae collected in a single planktonic net haul conducted in shallow coastal waters of the Golubaya Bay, Gelendzhik area, Caucasus. The larvae were subsequently settled in a small glass container and resulting colonies were maintained in an aquarium with a salinity level of 18 psu for approximately nine months, but in June 2018 all colonies died due to uncontrolled bloom of filamentous algae. The presence of symbiotic algae of the family Symbiodiniacea in tissues of colonies is shown. Phylogenetic analysis using mitochondrial (COI) markers revealed a high degree of similarity between the Black Sea zoantharian and Isozoanthus sulcatus (Gosse 1860) from European seas.

Until the middle of the last century, the Palearctic-Siberian gastropod fauna that inhabited the ‘sors’ and small coves of the larger bays of Lake Baikal was similar in environmental factors to Siberian water-bodies. Endemic species occupied open areas of the lake, with cold water, strong storms, and other specific environmental conditions. Based on morpho-anatomical characters and genetic distances of the COI mtDNA gene fragment between related species, five alien species were identified from open Baikal waters. In addition to the previously found Radix auricularia (Linnaeus, 1758), there were Radix cf. zazurniensis (Mozley 1934) (Lymnaeidae), Cincinna sorensis (Dybowski 1886) and C. cf. korotnevi Lindholm 1909 (Valvatidae), as well as Gyraulus cf. acronicus (Férussac 1807) (Planorbidae). A schematic map of the records of the alien species in the open littoral of the lake is presented, based on material taken by expeditions carried out in 1993–2023, as well as photographs of the shells and reproductive organs for some of the alien species, and information on coexisting endemic species of gastropods are given. We found albino individuals among R. auricularia and a few snails of R. cf. zazurniensis with afallic copulatory organs. Possible reasons for the invasion of the alien species and possible invaders into the open waters of Baikal are discussed.

An assumed shift of the tortoiseshell butterfly, Aglais urticae to synanthropy in extremely cold regions (with temperatures close to –60^оC) is tested. The tortoiseshell butterfly overwinters at the stage of imago; their cold resistance being fundamentally insufficient for surviving the cold across most of their distribution range in natural shelters located above the snow level and in unheated buildings. The species' resistance to cold from England to northeast Russia is increased from –22 to –29^оC, while the average minimum air temperature in January drops from 3.3 to –55.7^оC. The objective of the present work was to find out whether well-built, but unheated houses (the village of Seimchan) provide winter indoor temperatures above –30^оC, a threshold for the tortoiseshell butterfly. Winter temperatures were measured with loggers in two different houses and compared with the outside temperature obtained from weather station data. During a severe cold weather, it was 11–19^оC warmer inside the houses than outside, but the minimum temperatures below –30^оC were recorded over half of the winter, and below –35^оC over almost its third. Thus, winter (unhea- ted) houses, as well as demi-seasonal ones, and natural shelters such as cracks under the bark, hollows and other cavities located above the snow cover fail to provide the required temperatures. Unheated well-built houses guarantee successful hibernation for the tortoiseshell butterfly only in the milder climatic conditions of western Siberia and in the northeast of the European part of Russia. Wintering above the snow level in primitive shelters can only be possible within the temperature range of –31...–20^оC and west of it. The results of the work prove the idea of tortoiseshell butterfly synanthropy to be unsubstantiated and return to the idea of its wintering under the snow cover in shelters such as cavities in litter, under fallen trees, etc. This type of wintering guarantees success, being independent from the climate of northern Eurasia.

Morphometric analysis of skulls of the brown bear (Ursus arctos L.) showed the existence of two populations of this species in Tibet in the 19th century. The distribution of the northern population-I included the Qilian Shan and Kunlun mountain ranges bordering the Tibetan plateau from the north and pe- netrated into the northern part of the plateau, northwestern Qinghai Province, PRC. The distribution of the southern population-II included the upstream reaches of the main rivers of Tibet, viz, Huang He, Yangtze and Mekong on the plateau, southeastern Qinghai Province and, most likely, the whole of southern Tibet, including the Himalayas of Nepal. The diagnostic features of the two populations are choanae parameters, choanae width in males and choanae depth in females. The noted peculiarities of Tibetan brown bears may be related to the anatomical structure of the nasopharynx, an organ of the respiratory system that ensures the air to be warmed to an optimal temperature before it reaches the bronchopulmonary tissues. The divergence of Tibetan brown bear populations may be related to the settlement of the high plateau from both southern and northern refugia of the last glaciation. The currently accepted name of the subspecies of the Tibetan bear, U. a. pruinosus Blyth 1854, is suggested to be retained for the southern population-II, and that its junior synonym, U. lagomyiarius Przewalski 1883, be restored to designate the northern population-I. Clarification of the taxonomic status of the different bear populations in Qinghai Province, PRC, the most human-exploited part of Tibet, could affect the assessment of their conservation status, which is currently defined by IUCN for all bears in Tibet as LC (“Least Concern”).

The marking behavior of the common hamster, Cricetus cricetus in the wild was recorded using camera traps and handheld video in the N.I. Bagrov Botanical Garden, Simferopol, Crimea. We described the following types of scent marking: with flank glands (in particular, compass-like movements in the grass and rubbing on a stone), midventral gland marking, etc. The variety of marking behavior types on different substrates may contribute to a more efficient use of olfactory signals in maintaining the social structure of the common hamster, which is notably important at high population densities in urban areas.

The morphological and morphometric characteristics of water vole embryos are studied. Embryo implantation occurs on the 5^th day of pregnancy. A description of the morphological features of embryonic development at different stages of pregnancy is given, with equations for embryo body weight and length revealed. The results of multiple regression analysis show that embryo weight, when considering the influence of gestational age, is negatively related to the number of live embryos. Our results complement the existing literature on the biology of mammalian development and may be useful for establishing equivalent stages of embryonic development in different species when conducting comparative studies. Morphological features of development and the embryonic growth equations can be used to determine the age of pregnancy and the calendar dates of the beginning and end of the breeding season in natural populations.