Fluctuating Asymmetry in Cranial Measurements of East European Voles (Microtus rossiaemeridionalis Ognev, 1924) from the Zone of Radioactive Contamination

Fluctuating asymmetry (FA) in eight cranial measurements was studied in Microtus rossiaemeridionalis voles from two sites of the zone affected by the Totsk Radioactive Trace (TRT) and in the control population. In the affected populations, generalized mean population parameters of FA were significantly higher than in the control and tended to increase in relatively larger animals. The disturbance of ontogenetic homeostasis in voles from the TRT zone probably resulted from environmental stress caused by contamination with radionuclides (primarily plutonium), which entailed irradiation of many vole generations over more than 40 years.     

Phenogenetic Analysis of Pygmy Wood Mouse (Apodemus uralensis Pall.) Populations in the Zone of the Eastern Ural Radioactive Trace (EURT)

Monitoring of A. uralensis populations in Kamenskii raion, Sverdlovsk oblast, in 1992–2002 and in Kaslinskii raion, Chelyabinsk oblast, in 2000–2001 revealed an increase in the proportion and diversity of minor morphogenetic aberrations and abnormalities in the structure of the cranium along the axis of the Eastern Ural Radioactive Trace (EURT). The samples from the southern and northern parts of the EURT (contaminated with ⁹⁰Sr to 500 and 4 Ci/km², respectively) were characterized by directed deviations from the control with respect to the frequencies of phenes of nonmetric cranial traits and an increase in the level of their fluctuating asymmetry in young females, which is indicative of epigenetic rearrangements in populations living in a radioactive environment.     

Change in the Life Cycle Strategy of Fish under the Effect of Chronic Water Pollution

Fish of a polymorphic and evolutionarily young species Coregonus lavaretusfrom a subarctic lake that has been polluted for more than 60 years are used as an example for analyzing principal trends in the dynamics of structural and functional organization of fish populations. It is shown that fish exposed to sublethal doses of toxic substances for a long time have a smaller body size, the period of their sexual maturation becomes more variable, and the frequency of spawning and life span decrease. The biochemical and bioenergetic mechanisms of variation in populations are analyzed. The ecological expediency of change in the life cycle strategy corresponding to r-selection (conversion to a short reproductive cycle) is substantiated.     

Specific Cytogenetic Characteristics of Pinus cretaceae and Pinus sylvestris

A comparative cytogenetic study has been performed in four populations of two pine species, Pinus cretaceae Kalen. and P. sylvestris L., growing on sandy and chalky substrates in Voronezh and Belgorod oblasts. Significant differences in the parameters of mitotic and nucleolar activities, as well as the rate and spectrum of mitotic pathology, between populations of P. cretaceae and P. sylvestris and between populations of P. cretaceae growing under different conditions have been found. Populations of P. sylvestris growing on sandy and chalky substrates differ from each other in nucleolar activity. These differences may be adaptive and reflect the characteristic metabolic patterns and biological plasticity of pines growing under specific conditions.     

Population genetic structure of Pinus tabulaeformis in Shanxi Plateau, China

Chinese pine, Pinus tabulaeformis Carr., a species that ranges broadly across northeastern to southwestern China, plays a vital role in the maintenance of the structure and function of these ecosystems. In this study, we examined the genetic diversity of five widespread populations in Shanxi Plateau, the distribution center of Chinese pine, using 15 random amplified polymorphic DNA (RAPD) primers and five inter simple sequence repeat (ISSR) primers in 140 individual tree samples. Similar genetic differentiation results were obtained from the data of RAPD and ISSR. Based on the two sets of data, Nei’s genetic diversity was 0.2842 and 0.3078 and Shannon’s indices of diversity were 0.4332 and 0.4468. Genetic diversity at the species level was found high relative to that for other genera of Pinaceae. The greatest diversity was observed in the Lingkong Mountain population (0.3860), while the lowest was recorded in the Luya Mountain population (0.3352), most likely as a result of natural adaptation and anthropogenic perturbation. The relative magnitude of differentiation among populations (G _ST) was 0.1491 and 0.1356, respectively, implying that most genetic variation was within the populations (∼0.8509), rather than among populations. Published in Russian in Ekologiya, 2008, No. 1, pp. 36–42. The article was translated by the authors.     

Biodiversity, food consumption and ecological niche dimension: a study case of the riverine populations from the Rio Negro, Amazonia, Brazil

In this study we perform an ecological analysis of the resources use in the diet of the ribeirinho populations of the Barcelos municipality, Rio Negro, Amazonas, Brazil. Data on food composition, seasonality, and origin took place during three field trips between 1999 and 2000. Data were gathered based on structured interviews and observations from a total of 320 meals of 114 randomly selected families and 164 fishing trips. The staple food of the studied populations is based on fish and manioc, although the food niche amplitude can vary according to the factors such as the access to imported food items, resources seasonality, and socio-economic conditions. The migration to urban centers along with the changes in subsistence activities (reduction of small-scale agriculture and specialization in commercial fishing) may result in changes in the food habits of ribeirinho populations from Rio Negro.

The Spatiotemporal Structure of Rodent Populations in the Steppe Zone of Western Siberia

The spatial structure of populations has been studied in two rodent species inhabiting the subzone of meadow steppes of the steppe zone of Omsk oblast: the narrow-sculled vole (Microtus gregalis Pall.) and steppe lemming (Lagurus lagurus Pall.). Their populations are represented by combinations of territorial family groups whose structure and spatial distribution vary by season depending on population density, the phase of the population cycle, and the status of their members in the population. In the areas cohabited by M. gregalis and L. lagurus, the pattern of territory use and the rhythm of animal activity during the day depend primarily on their total density: under conditions of low density, the population groups of both species are spatially separated; at increased density, they are distributed with respect to the pattern of daily activity. Both species jointly use part of the territory but at different times of day: M. gregalis, mainly at night and in the morning; L. lagurus, in the daytime.     

Temperature adaptation of the heart in the grass snake (Natrix natrix L.), common European viper (Vipera berus L.), and steppe viper (Vipera renardi Christoph) (Reptilia: Squamata: Serpentes)

Changes in the heart rate (HR) in more and less thermophilic reptiles (Natrix natrix L., Vipera berus L., and V. renardi Christoph) exposed to heating from 0 to 40°C under anesthesia have been found to depend on the previous adaptation of the animals to the temperature parameters characteristic of the natural habitats of their populations.     

Spatial Distribution of Sables in the Middle Ob Region

Results of stationary studies on the spatial location of sables (Martes zibellinaL.) belonging to different age and sex groups are summarized. Mapping the sites where 388 animals were taken, it was found that young animals tended to live near floodplains; adult animals, on watersheds. Analysis of sables taken by commercial hunters (n= 1833) made it possible to estimate the age composition and the degree and spatial distribution of the hunting pressure on sable populations in three areas of the Ob region. The spatial separation of young and reproductive animals is interpreted as a group adaptive response to the specific distribution pattern of different habitats typical of this species and to the pattern of animal elimination. It is proposed to use the specific pattern of animal distribution for maintaining the size of the population that is subject to hunting. Specifically, reserve (reproductive) territories should be organized in watershed areas.     

On the Population Structure of the Kamchatka Sable

The degree of morphological differentiation of sable (Martes zibellina L.) populations was studied in different physiographic regions of the Kamchatka Peninsula and the Penzhina River basin. According to craniometric data, the sables inhabiting the hilly Western Kamchatka Plain are larger than the animals from other regions. However, the analysis of phenetic variation in craniological characters and coat color showed that the sable samples taken within the peninsula were fairly homogeneous. On this basis, all sables inhabiting the Kamchatka Peninsula may be regarded as a single population.     

Morphological peculiarities as indicators of natural history of sable (<Emphasis Type="Italic">Martes zibellina</Emphasis>) in North-Asia Pacific coast

Few studies exist on phenotypic composition of the sable populations in the Russian Far East, China and Japan. We present new data on the morphological diversification of sable for 20 mainland and island populations in an effort to document existing variability and produce baseline data that would be useful in constructing phylogenies for this species. Сlinal variability of skull size, cranial phene, foramen in fossa condyloidei inferior (FFCI), and fur coloration is revealed. One district, Central Sikhote-Alin, is characterized by sables with the minimum cranial size and the maximum phene expression. The area between the Uda River and Goryun and Amgun rivers is inhabited by sables of the darkest fur coloration. Moving out from those areas in all directions we were detected a trend of increasing skull size, reduction of cranial phene, and decreasing color intensity of fur. The skull size of sable is consistent with Bergmann’s rule. Special attention paid to the particular morphological properties of insular populations in specific climatic conditions and under isolation from the continent. They are characterized by minimal expression phene FFCI (Bolshoi Shantar, Iturup, and Hokkaido islands) and larger skull size, especially in sable of Kamchatka Peninsula. It is hypothesized that the area of the lower Amur Basin was a source of sable postglacial dispersal on the Eurasian Continent.     

Variability of the Flower Structure in European Starflower (Trientalis europaeaL.) in Natural Populations

Flower variability was studied in natural populations of European starflower (Trientalis europaeaL.). The results showed that the flower structure in this species is determined by two parameters: the multiplicity of primordia of flower components and the uniformity of flower meristem development. The frequencies of nonuniformly developing flowers differs depending on the habitat. It appears that both parameters are largely determined by random fluctuations.     

Host Specificity of Flukes of the Genus Sphaerostomum (Trematoda: Opecoelidae) within Their Geographic Ranges

The host specificity of flukes belonging to the genus Sphaerostomum (S. bramae and S. globiporum) in the center and at the periphery of the genus range is discussed. Both fluke species are specific parasites of cyprinids. However, fish of nine other families and one cyclostome species have also been recorded as their hosts. At the periphery of the range, the spectrum of definitive hosts is broader than in the center owing to a greater number of unspecific hosts. In the center, unspecific hosts are represented by six fish species (Esox lucius, Misgurnus fossilis, Perca fluviatilis, Lota lota, Gymnocephalus cernuus, and Salmo sp.), four of which are predators. At the periphery, 11 fish species, including six predators (Anguilla anguilla, Barbatula barbatula, Cottus gobio, Cobitis taenia, Coregonus lavaretus, Salmo trutta, Alosa sp., Potamoschistus minutus, E. lucius, P. fluviatilis, and L. lota), and the cyclostome Lampetra fluviatilis are unspecific hosts. In the peripheral populations, compared to central, flukes manifest greater adaptive plasticity and can infest new hosts.     

Exoautometabolic regulation of transgenes in microorganisms

Data on the existence of a specific system regulating the growth, size, and structure of enterobacterial populations are first summarized in terms of the chemical ecology concept formulated by S.S. Shvarts. The role of this system in transgene functioning is described using the example of the lux operon integrated into Escherichia coli. A relatively simple test for estimating such interactions is proposed.Translated from Ekologiya, No. 2, 2005, pp. 91–96.Original Russian Text Copyright © 2005 by Pshenichnov, Maslennikova, Nikitina.     

Experimental Study on the Effects of Population Density of Bloodsucking Mosquito (Aedes communis Deg.) Larvae on Their Biological Characteristics

Results of laboratory experiments on the effects of population density of Aedes communis Deg. larvae on their growth, survival, and sex ratio are presented. At the highest density, larval mortality increased by factors of 1.5 and 2.2, the duration of preimaginal development increased significantly, and the weight of pupae was 11 and 14.7% smaller than in low-density populations. The sex ratio was the same in both cases. The absolute numbers and the biomass of insects per cultivation vessel were greater in high-density populations.     

Proliferative Activity of Corneal Epithelium and Specific Features of Morphogenesis in Postmetamorphic Rana arvalisNilss. in Urbanized Areas

The mitotic activity and sizes of corneal epithelial cells in postmetamorphic Rana arvaliswere studied in the populations exposed to different degrees of anthropogenic impact in the city of Yekaterinburg. The studies were conducted at the initial stages of frogs' terrestrial life in three consecutive years. Mitotic activity exhibited a slight positive correlation with the liver index, which indirectly reflects the general metabolic rate in young frogs. The combined estimation of proliferative activity, epithelial cell size, and relative liver weight had the highest information value. There was a relationship between the mitotic index and liver index in young frogs from habitats with the highest level of anthropogenic transformation. This indicates that morphogenesis is well-balanced and is likely to decrease the probability of morphological abnormalities in frogs developing in the unstable environment. This physiological property allows the populations to exist and reproduce in urbanized areas.     

Hunting Selectivity and Its Influence on the Structure of Sable Populations in the Cis-Ural Region

The structure of commercial sable samples from the Cis-Ural region was studied taking into account hunting method (shooting or trapping). The proportion of adult animals was found to be significantly lower in samples taken during the first half of the hunting season, compared to the second half, indicating predominant harvesting of young animals. To estimate the degree of hunting selectivity (I), the ratios of demographic groups among shot and trapped animals were calculated. The results confirmed the fact of selective hunting for underyearlings both by shooting (I = 1.49–1.60 for the Cis-Ural region and I = 2.46–3.37 for the Western Sayan Mountains) and by trapping (I = 2.80–4.37), especially during the first half of winter. Samples taken during the second half of the season were characterized by prevalence of adult animals making up the reproductive core of the population (I = 1.43–2.07). It is considered that the process of reproduction in Cis-Ural sable populations in the 1960s to 1980s was stimulated by intensive commercial hunting. To maintain reproduction of sable populations at a safe level, it is necessary to reduce the period of hunting in the first quarter of the year. It is proposed to use the phenomenon of hunting selectivity for managing sable populations, regulating their exploitation, and improving the economic productivity of habitats. Commercial hunting in terms of its impact on the population can act as a factor of conscious or unconscious artificial selection.     

Phenes of Woody Plants: Identification,Scaling, and Use in Population Studies (An Example of Pinus sylvestrisL.)

The methods of identification and scaling of phenes of forest plants are described. The phene identification consists of five stages. Specific features of studies at each stage are shown using identification of the phenes of seed color, cone color, and seed scale structure in Scotch pine (Pinus sylvestrisL.) as examples. The method of phene scaling is based on the comparison of phene frequencies in a bog and in adjacent upland populations of pine. At the boundary between the bog and dry land, the frequencies of population-level phenes change, whereas those of superpopulation-level phenes remain unchanged.     

Biotopic Variation and Phenogeography of Dreissena polymorpha (Pallas)

The phenetic structure of Dreissena polymorpha populations in different water bodies is considered. The phenotypes of shell pattern and sculpture are identified and described using a scheme based on elementary characters, or pattern elements. It is shown that the frequencies of phenes in mollusks from different biotopes of the cooling system of two thermal power plants differ significantly. The data on species phenogeography are reviewed.