Vol 45, No 4 (2018)

An analysis of our own data and published data on comparable standard metabolism in vertebrates has been carried out. It was shown that within each family and most of the orders this parameter varies insignificantly and the mean values for the comparable standard metabolism are grouped around certain values presumably corresponding to the stationary states to which organisms aspire in the course of evolution. There was a significant difference in the comparable standard metabolism in poikilothermic and homeothermic animals, apparently related to the existence of a heat barrier, which is overcome by the appearance of thermoregulation. In total, seven levels of stationary states were distinguished for vertebrates and 12 of them for all animals. It was established that the ratio of the values of the comparable standard metabolism for neighboring levels varies insignificantly and is ~2.2. It was noted that in the process of macroevolution of phyla and classes, their constituent units occupy ever higher stationary levels. A possible mechanism of transition from one stationary level to another is discussed.

The population diversity of the frit fly Meromyza saltatrix from Poland, Mongolia, and several regions of the Russian Federation was analyzed by morphometric and molecular data on the mtDNA locus COI. Two phenotypes that correspond to two haplogroups (19 haplotypes) were identified by the absence or presence of black setae on the lower surface of the genae. A remarkable clinal variability among populations was demonstrated by the total area and area of the projecting part of the anterior processes of postgonites (APP), which play a critical role in the success of male copulation. Each parameter analyzed divided populations into four groups. Close populations with a natural barrier vary in the total area of the anterior process of the postgonite. We found an increased number of mutations including transversions in frit flies from Mongolia. Populations from Zvenigorod, South Ural Nature Reserve, and Mongolia might be of a later origin. The presence of particular haplogroup in the West European population of M. saltatrix with black setae, which is a unique feature of West European species of Meromyza, and their similarity to the Crimean population by the morphometrics of the APP is an indication of the possible isolation of this population in southern Europe during Quaternary glaciations with subsequent expansion to the northern part of the geographical area.

The results of analysis of the frequencies of t-alleles and heterozygous +/t individuals of house mice of different subspecies (musculus, bactrianus, tataricus, wagneri, and gansuensis) are presented for the natural populations inhabiting eight cities and five regions of Russia and adjacent countries of Eastern Europe and Asia. It is shown that the frequencies of t-alleles are 0.18 ± 0.03 in small samples (1–30 individuals) and 0.09 ± 0.06 in medium-sized samples (31–60 individuals). The factors that reduce the frequencies of t-alleles in natural populations and the mechanisms that prevent invasion and fixation of t-mutant alleles in the Mus musculus genome are discussed.

According to data on the abundance of taxonomic, physiological, and ecotrophic microbial groups, analysis of the seasonal changes in their composition under conditions of artificial (irrigation) and natural (wet land formation) soil moistening was carried out. It was revealed with statistical reliability that the greatest response to changes caused by different soil moistening modes was observed in the numbers of aerobic cellulose-degrading microorganisms, denitrifiers, and fungi. An increase in erosion resistance of steppe soils during irrigation is explained by the combined effect of physicochemical and biological processes, and by higher numbers of algae, fungi, aerobic cellulose-degrading microorganisms, and oligonitrophiles, in particular.

The mathematical model of host–parasite relations suggested previously by the authors was applied to analyze the formation of the aggregated distribution of parasites in the case of the host plant–parasitic nematode system. For nearly the same conditions and empirical infection levels, nematode abundances in the host population followed the gamma distribution. Exposure to temperature stresses modifies the resistance of the plant population to infection. Experiments with prolonged chilling of potato plants prior to nematode infestation revealed no statistically reliable increase in the share of resistant plants compared to the control, although the mean and the range of variation of the infection rate, as well as the aggregation of the parasite distribution, decreased. Short-term chilling of the plants prior to infestation led to a reliable decrease in the mean abundance of parasites and to the lowest aggregation of the parasitic nematode in the host plant population. The results of this study showed that this temperature stress caused potatoes to develop a reliably high and uniform resistance to the nematode.

The most complete data on the peculiarities of seasonal biology of gamasid mites of the genus Spinturnix, which are ectoparasites of bats of the boreal zone of the Old World, are presented. Data on the dynamics of the sex and age structure of superpopulations of parasites throughout the year are presented; the infestation of various bat species is analyzed, and the factors affecting it are discussed. The main differences between the life cycles of the boreal and subboreal Spinturnicidae mites were revealed.

Pup survival and growth rates were monitored to determine whether paternal care potentially contributes to reproductive success of male common voles Microtus arvalis Pallas, 1779. The subjects were 258 pups from 47 litters obtained from adult voles trapped in the wild. Reproducing pairs were formed and divided onto two groups in accordance with the age and parental experience of the reproducing individuals: group I included pairs with subadult males and nulliparous females; group II included pairs with adult males and multiparous females. Each of the groups was divided into two subgroups: in subgroups Iа (n = 13) and IIа (n= 11), litters were raised by females without sires; in subgroups Ib (n = 12) and IIb (n = 11), litters were raised by both parents. The litter size was recorded at parturition and again when the young were 12, 21, and 30 days old. Pups in each litter were weighed at parturition and also again when the young were 12, 21, and 30 days old. This study has shown that the presence of the sire may negatively affect both survival and growth rates of the pups, but this effect is dependent on the age of the reproducing individuals.

It has been noted that the introduction of small doses of dry prepupae of Hermetia illucens flies into the diet of the young Mozambique tilapia Oreochromis mossambicus (0.5 g/kg feed) had a positive effect on the growth and development of fish. It was found that the average daily gain in the experimental group was 0.7 g. It was established that the blood biochemical parameters were within the norm in the fish of all groups; however, in the experimental tilapia, the erythrocyte sedimentation rate was significantly lower and a tendency to increase in the amount of hemoglobin and glucose was noted. It was revealed that in the seminiferous tubules of fish in the experimental group, the number of mature sperm was 5.9 times higher compared with the control, indicating an increase in the rate of spermatogenesis. It is assumed that the observed effects are due to the high content of manganese in the prepupae present in a biologically active divalent form.

The effect of acute restrained stress on cognitive functions and anxiety-like behavior in white rats has been studied; furthermore, the influence of the fragment ACTH(4–10) analog Semax on the stress effects was evaluated. It was shown that stress exposure leads to impaired retention of previously acquired food-motivated maze task as well as reduced anxiety-like behavior in the elevated plus maze in rats. Preliminary intraperitonial administration of Semax (0.1 mg/kg) attenuates cognitive impairment caused by acute restrained stress, but it does not affect stress-induced changes in anxiety.

The contents of eight trace elements (Ti, Mn, Ni, Cu, Zn, Sr, Ba, and Pb) in muscles of syntopic sexual and clonal spined loaches (the golden loach Sabanejewia baltica, diploid males and females of Cobitis taenia, and congeneric triploid clonal females) from the upper Dnieper River and in the syntopic spined loaches (males and females of C. melanoleuca and males of C. taenia) from the upper Volga River basin were determined using the X-ray fluorescence spectroscopy technique. The contents of Cu in the clonal triploid Cobitis females and diploid C. taenia females from the Dnieper are different. The intersexual differences in the contents of Pb and Zn between C. taenia males and females, as well as the interspecific differences in the content of Ti between the spined loaches from the Dnieper and Volga basins were revealed. The concentrations of Cu and Pb correlated with the individual fish size. The potential for the use of the revealed differences in the trace element contents as an indicator of the divergence of ecological niches in the syntopic spined loaches is discussed.