Effect of temperature and density on larval pupation site preference in different species of Drosophila. - Vandal N.B., Siddalingamurthy G.S., and Shivanna N. - The larval pupation site preferences (PSP) in different species of Drosophila were studied at varied larval density and temperatures. Compared to control, at highest larval densities, the percentage of media pupation decreased and glass pupation increased at lowest temperatures in D. yakuba, whereas at highest temperatures with lowest larval density the media pupation increased. At all the larval densities studied; in D. mauritiana the glass and media pupation increased at 20њC, whereas at highest temperatures the media pupation increased and the glass pupation decreased, in D. rajasekari the cotton pupation and in D. virilis the glass pupation decreased and the media pupation increased at lowest and highest temperatures, the larvae of D. novamexicana prefer to pupate maximum on glass and minimum on media at lowest temperatures and at highest temperatures the pupation increased on glass and decreased on the media. In D. hydei the glass and media pupation decreased at lowest temperatures, and increased glass and decreased the media pupation at highest temperatures with highest and lowest density respectively. Statistical analysis has revealed that the variation of PSP in all the species with temperature, density, and sites is significant. These results show that at lowest and highest temperature and larval density the PSP significantly differ in all the species of Drosophila analyzed.

Key words: Drosophila, pupation site preference, density, temperature, larva, habitat choice.

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Centric diatoms (Bacillariophyta) in watercourses of Selenga river basin. - Kulikovski M.S., Devyatkin V.G. - 13 species of centric diatoms have been discovered in the Selenga river and its watercourses. Stephanodiscus makarovae and Cyclotella atomus var. gracilis are new species for the diatom flora of Mongolia. The centric diatom flora of the Selenga river watercourses is similar to that of other Asian rivers and Mongolian lakes with the exception of Hovsogol Lake. Data on the species occurrence frequency have been calculated. The flora revealed is analyzed ecologically and geographically.

Key words: centric diatoms, flora, Selenga river basin, Mongolia.

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Helminthic fauna of Siberian wood frog (Rana amurensis Boulenger, 1886) from Yacutia, its sex-age and seasonal variability. - Odnokurtsev V.A., Sedalishchev V.T. - Data on the helminthic fauna of Siberian wood frog (Rana amurensis) are presented. Samples of endoparasites from 621 Siberian frogs harvested in three regions of Yakutia in 1999 - 2006 were investigated. Of all the frogs, 564 ones were infected, namely, 515 with trematodes (the invasion rate is 82.9%), 471 with nematodes (75.8%). The total annual invasion varies from 81.6% in 2003 to 100% in 2006. 9 parasite species have been found in the Siberian wood frog inhabiting Yakutia, namely, 5 trematode species (Diplodiscus subclavatus, Haplometra cylindracea, Opisthioglyphe ranae, Pneumonoeces variegatus, and Pleurogenoides medians) and 4 nematode species (Rhabdias bufonis, Oswaldocruzia filiformis, Cosmocerca ornate, and Cosmocercoides pulcher). One of the C. pulcher nematodes was found in Siberian wood frogs only from the southern part of the region.

Key words: Siberian Wood Frog, Rana amurensis, invasion, trematodes, nematodes, extensively and intensively, index of abundance.

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Nutrition of Amur sleeper - Perccottus gleniii Dybowski, 1877 (Odontobutidae, Pisces) in reservoirs of its native and invasion habitats. - Plyusnina O.V. - Nutrition of Amur sleeper in several reservoirs of its native (Primorsky and Khabarovsk regions) and invasion (Tver and Moscow regions) habitats was studied. As a whole, the nutrition spectra are similar and show a large variety of food organisms consumed. The main distinction consists in the absence of tadpoles in the diet of Amur sleeper in its native habitat.

Key words: Amur sleeper, Perccottus glenii, feeding, invasion.

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Spatial distribution of terrestrial shell-bearing mollusks in Zasursky forest (Middle Volga region, Penza region). - Stoyko T.G., Bulavkina O.V., Mazei Yu.A. - The spatial distribution of terrestrial mollusks was investigated in several forest units different by their successional stage after felling. 29 snail species were identified. The most complex community variants are formed in the biotops of mixed forests with predomination of tillet, Norway maple, and asp as well as sub climax oak wood phytocenosis with a large part of European ash. Snail communities are poorer in birch woods and pine forests, which are anthropogenically disturbed. Forests restored after felling are considered as reserves of terrestrial mollusks in the whole ecosystem.

Key words: terrestrial mollusks, community structure, spatial heterogeneity, Penza region, Russia.

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Reproduction features of the Saiga antelope (Saiga tatarica tatarica L.) in Republic of Kalmykia in the low numbers' conditions - Arylova N.Yu. - Some reproductive indices of the European population of saiga with a very low abundance (less than 20 thousand individuals) have been analyzed using the literature data and original author's observations. Despite of the habitats' deterioration, infringement of the demographic structure, and critical reduction of the numbers the weight of newborn saigas governing their further development and life activities has been shown not to differ essentially from its value observed in the 1950ies when this population was at the maximum of its abundance (above 800 thousand individuals).

Key words: European population of Saiga antelope, abundance reduction, sex-age structure, rut, lambing, newborn's weight.

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Nutrition of oribatid mites of Crotonioidea superfamily in laboratory conditions. - Ermilov S.G., Chistyakov M.P. - Nutrition of 16 oribatid mite species of the Crotonioidea superfamily was studied In laboratory conditions. Of the offered food substrata all the species preferred food algae (Pleurococcus sp.). Other forages (Sphagnum sp., parts of birch leaves, Cladonia silvatica, wood, a crude potato) were eaten by these mites only as additional ones. By our observations, Heminothrus peltifer possessed the widest food spectrum.

Key words: oribatid mites, Crotonioidea, food.

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Aspects of ecological segregation and technology of specific identification of viper snakes (Reptilia: Viperidae, Vipera) in Volga region by genotyping. - Yefimov R.V., Zavialov E.V., Tabachishin V.G. - Ecological factors determining the distribution and participation in the formation of epigenetic landscape of geographical populations of Vipera nikolskii and V. berus are considered. The habitat of V. nikolskii in the Volga region is shown to reach north in the Volga valley to the lower zone of the Saratov reservoir (southward of Khvalynsk City, Saratov region); in western direction the habitat border passes through the territory of several southern districts of the Penza region, the Volga valley being the eastern limit of the habitat.

Key words: Vipera nikolskii, Vipera berus, genetic structure, distribution, habitat border.

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An approximate model of atmospheric transfer of toxicants in Teheran. - Ommi F., Nekofar K. - The influence of convex relief elements on the atmospheric transfer of pollutions is considered. For the flat relief of the surface of Teheran it manifests itself as compression of the isolines along the prevailing winds. A model of atmospheric dispersion of toxicants is offered with due account of the complex character of the spreading surface relief.

Key words: pollution, atmospheric transfer, relief, Iran.

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