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Volume 103, Nº 11 (2024)
ARTICLES
Ilya Sergeevich Darevsky. 100 years anniversary
3-6
I. S. Darevsky (1924–2009) and rock lizards of the Caucasus: from geographic parthenogenesis to reticulate (hybridogenous) speciation
Resumo
The path taken by I. S. Darevsky to the discovery of natural parthenogenesis in rock lizards of the Caucasus (1957, 1958) is tracked, as well as his further developments of the problem of parthenogenesis in lizards in his main papers (1962, 1966, 1967) and monograph (1967). The following issues are considered: geographic and hybrid parthenogenesis, subspecies and species in unisexual lizards, spontaneous males in parthenogenetic species, the essence of I. S. Darevsky’s discovery in the context of different categories of clonal reproduction in animals, the formation of the concept of reticular speciation, and the evolutionary age of clonal forms in various groups of animals.
7-39
Genetic variation and phylogeography of lacerta strigata eichwald, 1831 (Lacertidae, sauria)
Resumo
Seventy-six sequences of the cytb gene region of mitochondrial DNA (1143 bp) and 27 sequences of i7 β-fib nuclear DNA (483 bp) of Lacerta strigata from 57 localities in Abkhazia, Azerbaijan, Armenia, Georgia, Iran, and Russia were analyzed. A large number of new samples were included in analysis with special focus to the species’ range at the Caucasus Isthmus. An identical topology and four supported clades (lineages) resulted for both mtDNA and sequences combined with nucleDNA (Bayesian and Maximum Likelihood). Four haplogroups (clusters) have been identified in the median cytb haplotype network. The lizards of clade A (haplogroup I) are widespread throughout the species range, while lizards of clade D (haplogroup IV) show the most limited distrubytion. No genetically unique populations of L. strigata were detected in the Caucasian xerophilous refugia. Also, no genetically distinct populations of the species were recorded in the Hyrcanian climatic refugium (Southern Caspian region). An exception is the East Hyrcanian refugium, that is characterized by the most distant clade D (IV). The territory of Ciscaucasia and the Transcaucasian depression are occupied by a single clade each: A (I) and B (II), respectively. We detected several clades distributed in the four geographic areas (contact zones): in the Greater Caucasus, Alborz, Armenian Highland, and West Turkmenian Lowland. We associate the divergence of the L. strigata phylogenetic lineage with the Turkmen-Khorasan and, in particular, the Kopet Dag orogeny, as well as with the Late Miocene fluctuations in the level of the Eastern Paratethys, while the leading factor of intraspecific differentiation is the Pleistocene regressions and transgressions of the Caspian Sea. According to the current distribution pattern and species evolutionary history, L. strigata should be assigned to the Hyrcano-Caucasian zoogeographic group.
40–59
Genome size variation in diploid and polyploid mountain lizards of the genus Darevskia (Lacertidae, Squamata)
Resumo
The study of genome size variation in cells of vertebrates using the DNA flow cytometry makes it possible to precisely determine polyploid individuals, which is extremely important when studying the processes of reticulate speciation. In addition, in many groups of vertebrates, closely related species often differ in the nuclear DNA content. Therefore, the purpose of our study was to explore the variability of genome size and ploidy in populations of 29 species and subspecies of mountain lizards of the genus Darevskia, as well as their hybrids. As a result of the study, the range of variability in individuals of different ploidy (91% of diploid and 9% of triploid individuals) was established not to overlap. Among diploid species, no correlation was found between the nuclear DNA content and phylogenetic relationships, geographic coordinates, altitude, average annual temperatures and precipitation. Representatives of all studied species complexes (with the exception of D. adjarica) had approximately the same limits of variability. Two species (D. derjugini and D. saxicola) show significant intraspecific variability. Comparisons of the genome size of parthenogenetic and bisexual species generally revealed no noticeable differences between them. Studies of triploid hybrids have shown that their genome size as a whole roughly corresponds to the sum of the average size of the diploid genome of the maternal parthenogenetic species and the haploid genome of the paternal species. The variability of genome sizes within samples of triploid hybrids was on average slightly higher than in most parthenogenetic species, but some lower than in bisexual species. The paper discusses peculiarities of reticulate speciation in this group of animals.
60–74
Taxonomic diversity and biogeography of the snakes in the aralo-caspian basin
Resumo
Snake diversity of the Aralo-Caspian basin includes 61 species in 8 families, being composed of local faunas of the Northern Caspian Depression, the Greater Caucasus and Ciscaucasia, the Lesser Caucasus and Transcaucasia, the Alborz and Turkmeno-Khorasan mountains, the Aralo-Caspian Isthmus, the deserts and mountains of Middle Asia and the plains of the Aral Sea region. Regions with the richest snake diversity are Alborz, Turkmeno-Khorasanian Mountains and Transcaucasia. The snake fauna is composed of 25 biogeographic groups; all diversity of the distribution patterns is described by 10 main chorotype groups and 36 basic chorotypes. The most common element is Mediterranean (12 species), as well as Armeno-Iranian (7 species). Delta-diversity grows in the latitudinal direction, from the plains of the Aral Sea region and the North Caspian Lowland to the mountain systems of the Iranian Plateau. The level of species endemism is 25%. Six of the fourteen endemics live in the Alborz Mountains.
75–83
Overwintering strategy of the oriental fire-bellied toad, Bombina Orientalis f. Sylvatica (Amphibia, Anura)
Resumo
The cold tolerance, the attitude to dissolved oxygen depletion in water, and the overwintering strategy of individuals of one of the intraspecies forms of the Oriental fire-bellied toad, Bombina orientalis f. sylvatica were studied in the south of Primorye, Russian Far East. It was revealed that individuals of the study form were unable to tolerate a decrease in the level of dissolved oxygen in water below 6 mg/l, and slightly resistant to negative temperatures (surviving only for 1–4 days at –1.1 ± 0.1°C). The main stereotype of overwintering of the Bombina orientalis f. sylvatica was confirmed to be terrestrial hibernation. Similar studies on the second form of the species, f. praticola, may by confirm the validity of the segregation these two ecological forms within B. orientalis.
84–91
On the reproductive biology of the transcaucasian gyurza, Macrovipera lebetina obtusa (Dwigubsky, 1832) (Serpentes, Reptilia), in the NortheastERN Caucasus (Dagestan, Russia)
Resumo
Data on the reproduction of the Transcaucasian viper in Dagestan are presented. The studies were carried out in natural conditions and in captivity. To characterize clutches in nature, five females were captured after the mating period and then kept in a terrarium. The body length of females varied from 865 to 1040 mm. The number of eggs in clutches ranged from 12 to 24. The width of eggs in clutches averaged 36.8 ± 1.35, the diameter, 25.8 ± 0.21 mm, and the weight, 14.9 ± 0.13 g. Incubation in the laboratory conditions lasted 40–45 days. The body length with the tail of the hatched juveniles was 226.5 ± 2.93 mm, the weight, 9.4 ± 0.29 g. A positive correlation was found between the body weight of breeding females and the number of eggs they laid. A comparison of the weight and metric data of Dagestan and Azerbaijani individuals was carried out.
92-96
A new species of blind skink of the genus Dibamus Duméril ET Bibron, 1839 (Squamata, Dibamidae) from Сambodia
Resumo
We describe a new species of blind skink of the genus Dibamus Duméril et Bibron, 1839 based on five specimens collected from Bokor National Park, Kampot Province, southern Cambodia. Dibamus elephantinus sp. n. can be distinguished from its congeners by the following combination of morphological characters: snout-vent length (SVL) up to 129.3 mm; tail length comprises 17–22% of SVL; rostral suture incomplete; nasal and labial sutures complete; single postocular; three scales at the posteromedial edge of first infralabial; two scales at the posterior edge of second infralabial; the medial sublabial scale enlarged; 19 midbody scale rows; 22 transverse scale rows just posterior to head; 17–19 transverse scale rows just anterior to vent; 178–202 ventral scales; 46–52 subcaudal scales; relative size of frontal to frontonasal (FSW/FNSW) 127–136%; relative size of interparietal to surrounding scales (IPW/NSW) 111–140%; in males hindlimbs longer than head length (HLL/HL 74–78%); the light colored band on the body may be present or absent. We provide an osteological description of the new species based on micro-CT data. Genetically and morphologically Dibamus elephantinus sp. n. is most closely related to D. dalaiensis inhabiting the western part of the Cardamom Mountains in Cambodia. The new species inhabits montane evergreen forests of Damrei Range (also known as Elephant Mountains) at elevations of ca. 1000 m a. s. l. Our study brings the number of species in the genus Dibamus to 27; Dibamus elephantinus sp. n. is the second species of Dibamus to be recorded from Cambodia.
97-120