Статьи

The Common hamster (Cricetus cricetus) is the rodent with one of the largest range (6 million km²). There were four phylogenetic lineages earlier recovered in Western Europe, Ukraine and Bryansk Province of Russia: “North”, “Рannonia”, E1 and E0. E1 was previously reported from South-Eastern Poland and Western Ukraine and never been found in sympatry with “Pannonia” although the closest distance between them was estimated as 20 km. The question is whether the sympatry of E1 and E0 phylogroups exists?

With the urban-type settlement Stepnoe as an example, biodiagnosis of the soil of a settlement with low technogenic impact was conducted. In the course of our work, 30 soil samples were plated onto solid nutrition media to evaluate the following: the total numbers of heterotrophic microorganisms - on meat peptone agar, the numbers of hydrocarbon-oxidizing and iron-oxidizing microorganisms - on their corresponding selective media, and the activity of several soil redox and hydrolytic enzymes (dehydro-genases, catalases, peroxidases, and invertases) were also studied.

The effect of gamma radiation doses of 0, 2.5, 5.5 and 7.5 Gy received by Artemia cysts on the hatching of nauplii and post-nauplial survival of crustaceans was studied at salinities of 0, 9, 18, 36, 54, 62, 78 and 88 g/L. Under the same salinities, the above parameters were also estimated without irradiation. It has been found that the rate of nauplii hatching from cysts primarily depends on salinity, the coefficient of determination being 90%.

Data on the status of summer phytoplankton of the Usa river and its tributaries are given. 184 taxa of algae with a rank lower than the genus from 7 divisions were recorded in algoflora, with Bacillariophyta (43-57% of the composition) and Chlorophyta (23-47%) predominating in the rivers. The abundance range in algocenoses was 0.02 - 5.2 mln cells/L, that of biomass was 0.01 - 1.8 mg/L; the content of chlorophyll-a was 0.01 - 3.1 µg/L.