2013 Issue №7

This article argues that, in the estuaries the South Baltic, the bivalve molluscs Mya arenaria are capable of consuming an average of 6.5 % of the water body primary production. A numerical assessment of the filtration rate of these molluscs shows that they can filter daily an average of 2.41 ± 1.01 m3 of water per a square meter of the river bed. During the vegetation season, molluscs can clear approximately 380 m3 of water in estuaries removing up to 558.9 ± 65.7 g of suspended organic matters.

This article argues that the population index of talitrid groups on the coast of the Curonian Spit (the village of Lesnoi) in April-September of 2011 improved in comparison to those of 2001—2003, which is indicative of a considerable positive effect of a reduction in recreational pressure on the Curonian Spit and its beaches.

This article investigates the state of chironomid communities in Lake Penkovoe, Pond Isakovsky, Pond Shkolny, and the Karasevka pond system in Kaliningrad in spring 2011. The authors provide new data on the species composition, abundance, and biomass of chironomidae. The Shannon, Simpson, Balushkin, and Margalef indices were calculated for the chironomid communities. The authors identified the dominant species in the communities of chironomids and evaluated the quality of water in the studied water bodies over the period under consideration on the basis of the species diversity of chironomidae.

On the basis of 1948—2011 materials, this article characterises the zooplankton of three large lakes of similar age and origin found at different trophic stages and in different landscapes of the Pskov region. It is shown that the structural features of the organization and direction of succession of zooplankton communities are directly dependent on the landscape and genesis of the lake basin and, in their turn, can be used as an indicator of the successional stage of the aquatic ecosystem.

This article describes the features of quantitative distribution of glucocorticoid steroid hormones — hydrocortisone and corticosterone – at different stages of the life cycle of the Mediterranean mussel (Mytilus galloprovincialis) and the European flat oyster (Ostrea eduliss). The author identifies a common pattern of hormone dynamics consisting in a reduction in the level of hormones in molluscs in the course of maturation. Interspecies differences in the ratio of hormone levels are described. It is suggested that glucocorticoids participate in the regulation of gametogenesis of the investigated species.

This article presents the results of a study of the ecology of Erithacus rubecula carried out in anthropogenic habitats of the Ryazan region in 200—2010. The results of research reveal a few distinctive features in the biology of this species depending on the degree of biotopes’ anthropogenic transformation. First of all, it concerns bird nutrition. As the degree of anthropogenic transformation increases, the diet of the species contains more synanthropic invertebrates. Some birds start feeding on man-made products and associate with people in the process of foraging. The difference in the reproduction biology of the species can be reduced to the use of man-made shelters for nesting.

This article presents data on the taxonomy of birds in the Kaliningrad region in comparison to the materials of taxonomic surveys of birds in Belarus and other areas in Europe. It is the first part of the work focusing on the issue of subspecies affiliation of some breeding species of the orders Falconiformes, Galliformes, Gruiformes, Charadriiformes, Strigiformes, Piciformes. The second part, which is to be published in 2014, will consider the order Passeriformes.

This article provides historical data on lichenological studies carried out in Kaliningrad since the pre-war period and presents a list of species that have been described as residing on the city’s territory. The authors conducted a taxonomic, ecological (according to the main substratum types), and biomorphological analysis of the lichen of Kaliningrad. The article contains a schematic map of lichen species distribution on the territory of Kaliningrad.