Yellow wagtail Motacilla flava Linnaeus, 1758 (Passeriformes, Motacillidae, Motacillinae), in the Middle Volga Region: Geographical distribution, nesting biotopes, and numbers

A critical assessment of the literature data on the yellow wagtail Motacilla flava Linnaeus, 1758 (Passeriformes, Motacillidae, Motacillinae), at the turn of the 19th–20th centuries is carried out, assessment of its current numbers is given, and limiting factors and patterns of the species distribution on the study area of the European part of Russia, including the Middle Volga Region, are identified.     

Epibenthic predators control mobile macrofauna associated with a foundation species in a subarctic subtidal community

Foundation species (FS) are strong facilitators providing habitat for numerous dependent organisms. The communities shaped by FS are commonly structured by interplay of facilitation and consumer control. Predators or grazers often indirectly determine community structure eliminating either FS or their principal competitors. Alternatively, they can prey on the dependent taxa directly, which is generally buffered by FS via forming complex habitats with numerous refuges. The latter case has been never investigated at high latitudes, where consumer control is widely considered weak. We manipulated the presence of common epibenthic crustacean predators to assess their effect on mobile macrofauna of the clusters developed by a FS (barnacle Balanus crenatus and its empty tests) in the White Sea shallow subtidal (65° N). While predation pressure on the FS itself here is low, the direct effects of a spider crab Hyas araneus and a shrimp Spirontocaris phippsii on the associated assemblages were unexpectedly strong. Removing the predators did not change species diversity, but tripled total abundance and altered multivariate community structure specifically increasing the numbers of amphipods, isopods (only affected by shrimp), and bivalves. Consumer control in the communities shaped by FS may not strictly follow the latitudinal predation gradient rule.     

Indicators of Hypoxia Tolerance as Determined by Cellular Elements of Rat Blood

Journal of Evolutionary Biochemistry and Physiology - Although hypoxia tolerance is mainly determined genetically, it is important to study individual variability of animal organisms in order to...     

Multiple foundation species shape benthic habitat islands

Pattern generation by foundation species (FS) is a primary structuring agent in marine and terrestrial communities. Prior research, focused on single-species or guild-dominated habitats, stressed the role of facilitation in maintaining community structure. However, many habitats are developed by multiple FS from different guilds. Competition between these FS may provide an additional agent potentially responsible for spatial and temporal patterns. In the White Sea, epibenthic patches formed by barnacles (Balanus crenatus) and solitary ascidians (mainly Styela spp. and Molgula spp.) on small stones and empty bivalve shells (mainly Serripes groenlandicus) produce microhabitats for different sessile taxa. We hypothesized that: (1) several FS would provide habitats for most of other species in the community; (2) different FS promote different assemblages of sessile organisms; (3) the interplay of facilitation and competition best explains observed patterns of abundance and demography in FS; and (4) these interactions shape the whole community, increasing the diversity compared to less heterogeneous patches constituted by single FS. We examined 459 patches and the results generally supported this hypothesis. The number of FS in a patch positively affected species diversity. Most sessile species (72% of individuals) resided on barnacles, ascidians and red algae, except barnacles that dominated the primary substrate. The size structure of barnacles (live individuals and empty shells) and ascidians were interrelated, suggesting long-term patch dynamics whereby ascidians regularly replace barnacles. Following this replacement, we expect consequent changes to the entire dependent assemblage. Evidence for these changes exists in the spatial pattern: most sessile and motile taxa demonstrated significant associations with either FS. Our results indicate that the small-scale patterns observed in patches formed by multiple FS are primarily generated by facilitation of dependent taxa by FS, and facilitation and competition between different FS. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Dedicated to E. A. Ninbourg, our late tutor.     

Synchronous annual recruitment variation in barnacles and ascidians in the White Sea shallow subtidal 1999–2010

Multiple foundation species in a community may exhibit alternative ecological strategies. Barnacles Balanus crenatus Bruguiere and solitary ascidians Styela spp. often co-dominate on mixed sediments in the White Sea shallow subtidal, supporting numerous dependent organisms. Larvae of B. crenatus stay in plankton for several weeks, while ascidian tadpoles float for 1–2 days. Given this difference in spreading potential, we expected recruitment in barnacles and ascidians to be controlled by the factors operating at different spatial scales. In 1999–2010, we annually sampled the community dominated by barnacles and ascidians to relate their recruitment rates to the substrate space availability, abundance of adults, and climatic variables. Most barnacles recruited to the surfaces of shells, stones, and conspecific adults. Ascidian recruits were chiefly found on barnacles. Annual recruitment rates of barnacles and ascidians were strictly correlated and strongly depended on average temperatures of the preceding fall (positively), winter (negatively), and current summer (negatively). Variation of mean annual recruitment rates was 26-fold for barnacles and 30-fold for ascidians. We found no limitation of recruitment by hard substrate availability. Inconsistent with our original hypothesis, large-scale environmental factors similarly accounted for most annual recruitment variation in both foundation species studied.     

IGFBP-4 Proteolysis by PAPP-A in a Primary Culture of Rat Neonatal Cardiomyocytes under Normal and Hypertrophic Conditions

Biochemistry (Moscow) - Cardiovascular diseases (CVD) are among the leading causes of death and disability worldwide. Pregnancy-associated plasma protein-A (PAPP-A) is a matrix metalloprotease...     

Cultivation of Melanoma Cells in vitro on a 3D Scaffold Prepared on the Basis of Gelatin

Cell and Tissue Biology - Organotypic cultivation of melanoma cells in a three-dimensional matrix that mimics the dermis is a promising area of investigation for modeling a tumor and studying its...