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Seasonal dynamics of population density and biomass of Hemidiaptomus hungaricus Kiefer, 1933 (Copepoda, Calanoida) in temporary reservoirs in the Saratov region. - Yevdokimov N.A., Yermokhin M.V. - The seasonal dynamics of the population density and biomass of Hemidiaptomus hungaricus in temporary reservoirs in the Saratov region with various hydrological modes is analyzed. The population density dynamics of nauplii is determined by features of the hydrological mode of a reservoir, and copepodits show a dependence on the spatial structure of a population as well. The quantitative dependence of the development duration of nauplii, copepodits and adult crayfishes on the average water temperature has been revealed.
Key words: Hemidiaptomus hungaricus, population density, biomass, temporary reservoirs.
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Expansion dynamics and modern abundance of Melanocorypha calandra and Melanocorypha leucoptera in the Northern Lower-Volga region. - Zavialov E.V., Tabachishin V.G., Mosolova E.Yu. - The expansion dynamics of Melanocorypha calandra and M. leucoptera is considered on the basis of our field surveys conducted within the Saratov region and adjacent territories in 2000 - 2006 and analysis of the literature. A tendency of expansion of the M. calandra and M. leucoptera habitats is observed for the first years of the 21 century while their population density has increased by 1.5 - 2 times in comparison with recent years. Positive long-term tendencies in transformation of their habitats under the influence of macroclimatic trends and anthropogenic factors are predicted.
Key words: Melanocorypha, abundance, biotopical distribution, habitat, Saratov region, Russia.
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Age structure of Helichrysum arenarium (L). Moench cenopopulations in the Northern Lower-Volga region. - Kashin A.S., Bulanaya M.V., Zhulidova T.V. - 10 Helichrysum arenarium cenopopulations from six districts of the Saratov region were studied in 2003 - 2006 and found to be normal, not full-membered. The onthogenesis of H. arenarium in the regional conditions is complete. The basic spectrum of H. arenarium for the Saratov region is left-sided. Its annual variation reflects the result of fluctuations in the temporal structure of the cenopulations, related to abiotic factors.
Key words: Helichrysum arenarium, cenopopulation, age status, age structure, Saratov region.
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Current status of fish population in Penza reservoir. - Osipov V.V., Yankin A.V., Il'in V.Yu. - According to our research (2002 - 2004, 2006) and literature data, the current status and life table of the Penza reservoir's fish were determined. Lately the primary commercial fish species, its composition and abundance have redistributed. On the basis of catch registration some increase in numbers of bream Abramis brama and that of silver bream Blicca bjoerkna and some decrease in numbers of roach Rutilus rutilus are observed. These changes may be caused by an increase of the trophic level in the Penza reservoir.
Key words: fish population, abundance, reproduction, eutrophication, Penza reservoir.
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Age determination of young Rhombomys opimus Lichtenstein, 1823. - Leontieva M.N. - A table of Rh. opimus development has been composed. It is based on features of Rh. opimus development in the farm conditions, which are close to nature. The table shows five age groups differing in fir cover and physiological peculiarities. The table can be used for age determination of Rh. opimus in the laboratory and in wildlife.
Key words: Rhombomys opimus, development, morphophysiological change, age groups.
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Ecologo-cenotic characteristics of the habitats of some protected plants of the Southern Saratov Cis-Volga region. - Davidenko O.N., Nevsky S.A., Berezutsky M.A. - The paper provides a detail description of five protected plant species habitats in the southern part of the Saratov Cis-Volga region. Most typical associations and their ecological characteristics of humidity, soil fertility, and light intensity have been established. The species' structure stability of these habitats has been evaluated.
Key words: vascular plants, vegetative association, ecoton community, Saratov region.
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Mainothrus badius as a little known species of oribatid mites (Acari, Oribatida) and its geographic distribution in Russia. - Ermilov S.G., Chistyakov M.P. - An oribatid mite of M. badius from the Mainothrus (Oribatida, Trhypochthoniidae) genus was found in the Nizhniy Novgorod region for the first time. Earlier rare findings of this species in Russia was recorded only in Karelia, the Smolensk and Moscow regions. The geographic distribution of M. badius in Russia is discussed.
Key words: oribatid mites, Trhypochthoniidae, Mainothrus, geographical distribution.
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Distribution of ground-beetles of genera Calosoma F. Weber, 1801 (Coleoptera, Carabidae) in the Saratov Cis-Volga region. - Sazhnev A.S. - The spread and biotopical distribution of ground-beetles of the genera Calosoma in the right-bank districts of the Saratov region are considered. An ecologo-faunistical characteristic of the ground-beetle species is presented. A determinant of species for the Saratov region is offered.
Key words: ground-beetles, Calosoma, distribution, Saratov region.
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Abundance dynamics of mouse-like rodents in the steppe Saratov Cis-Volga region. - Tsvetkova A.A. - Features of the abundance dynamics of mouse-like rodents in both natural and anthropogenic habitats on a plot of typical feather-grass and tipchak steppe in the Saratov Cis-Volga region are considered. Some similarity in the course of the abundance dynamics of the background species (Apodemus agrarius, A. uralensis, Microtus arvalis) has been revealed, a high abundance of the rodent populations in 2007 has been registered.
Key words: petty mammals, rodents, background species, abundance dynamics, fluctuation amplitude, steppe, Saratov Cis-Volga region.
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