Morphological Variability of Roach <Emphasis Type=Italic>Rutilus rutilus</Emphasis> (L.) from the Volga Reach of Rybinsk Reservoir

A comparative analysis of literature data and our own results on the morphology of roach from the Volga Reach (Rybinsk Reservoir) in different years is conducted. Recently, (from 2007 to 2010), the morphological characteristics of the roach have been similar to those observed between 1976 and 1978. The roach is characterized by an intermediate position between the herbivorous and malacophagous morphs, but it is more similar to the herbivorous morph.     

Comparative analysis of generative parameters of the roach <Emphasis Type=Italic>Rutilus rutilus</Emphasis> (L., 1758) in the Volga reach of the Rybinsk Reservoir

An analysis of the reproductive potential of roach in the Volga reach of the Rybinsk Reservoir is made on the basis of published data and our own data obtained from 1953 to 2012. Values of fecundity obtained in the 2000s are the most similar to the results of 1976. Parameters of the intensity of the generative exchange of females (absolute and relative fecundity and size and mass of eggs) were high in 2007 and 2012, which indicates a sufficient food supply, especially of medium and large roach.     

Reproductive parameters of roach <Emphasis Type="Italic">Rutilus rutilus</Emphasis> (L.) from the Rybinsk Reservoir reaches differing in anthropogenic loads

The results of a study on the parameters of reproductive capacity in roach from the Sheksna and the Volga reaches of the Rybinsk Reservoir are presented. The Volga reach is relatively clean, while the Sheksna reach is subject to the strongest anthropogenic load. In 2011, the average values of the absolute and relative fecundity, as well as the egg size, in roach Rutilus rutilus (L.) from the Volga reach were higher than those in roach from the Sheksna reach, but differences are mainly statistically insignificant. The data of the study indicate the adaptation of the investigated roach to the negative influence of the Sheksna reach contamination and, in particular, its preservation of a sufficient level of reproductive capacity.     

Effect of thyroid hormones on activity dynamics of enzymes of intestinal mucosa of juvenile roach <Emphasis Type=Italic>Rutilus rutilus</Emphasis>

The effect of thyroid hormones on activity dynamics of enzymes (proteinases and glycosidases) of intestinal mucosa of juvenile roach Rutilius rutilus was investigated. Application of substances increasing and decreasing the level of thyroid hormones in blood plasma significantly influences the growth rate and the activity of proteinases and glycosidases functioning in the intestinal mucosa. In most cases, the activity level of trypsin-like proteinases and the activity of glycosidases in the fish exposed to triiodothyronine were significantly higher than in the control. The activity level of chymotrypsin-like proteinases in fish form the group with exposure of exogenous triiodothyronine only in the end of the experiment surpassed the values of this parameter in the control fish. In the fish developing at deficiency of thyroid hormones, the growth rate and proteinases activity were significantly lower in comparison with the control.     

Effects of an induced magnetic storm on the early ontogenesis of roach <Emphasis Type=Italic>Rutilus rutilus</Emphasis> (L.)

The influence that an induced magnetic storm (IMS) modeled in a confined volume has on the early ontogenesis of Rutilus rutilus was studied. The significant effects of the IMS were observed for the hatching rate of roach embryos, the size-weight and morphometric parameters of the fry, the variability of the vertebral column, and ontogeny stability in the roach offspring.     

Comparison of two kinds of functional asymmetry in the roach <Emphasis Type=Italic>Rutilus rutilus</Emphasis> (Teleostei: Cyprinidae)

In the higher vertebrates, asymmetries of different functions of individual are poorly connected with each other. At present it is unknown whether this poor link is a secondary phenomenon or it is characteristic of different kinds of functional asymmetry already at early stages of vertebrate evolution. In connection with this problem, in the roach Rutilus rutilus was studied asymmetry of two behavioral reactions—movements in an annular corridor and of the C-shape body bending at a sudden action of electrical stimulus. Different individuals prefer a certain direction of movement in the corridor (to the right or to the left). Comparison of these two kinds of asymmetries in the same individuals has shown the absence of significant association between asymmetry of different reactions. The obtained data indicate that already in the lower vertebrates, different kinds of functional asymmetry are controlled by different mechanisms and are poorly associated with each other.     

Dependence that the community structure of the roach <Emphasis Type=Italic>Rutilus rutilus</Emphasis> (L.) parasites has on the host age

The changes that take place in the structure of the parasite communities of two roach populations as the hosts grow older have been studied in the Chivyrkuiskii Bay of Lake Baikal and the estuary of the Selenga River. The parasite communities are analyzed at the levels of host individuals (infracommunities), host age groups (sets of infracommunities), and host population (component community). The number of parasite species regularly increases as the roaches age in both aquatic bodies, whereas the evenness of the parasite communities decreases. The Berger-Parker dominance index of the parasite communities changes with the roach age in different directions, increasing in the Chivyrkuiskii Bay and decreasing in the estuary of the Selenga River. The changes in the Shannon diversity index for sets of infracommunities of roach parasites are the opposite of those in the Berger-Parker index.     

Specific features of thermoregulation behavior in early juveniles of roach <Emphasis Type="Italic">Rutilus rutilus</Emphasis> under thermogradient conditions

Specific features of thermoregulation behavior were studied, and values of the selected and final selected temperature (25.1°C) for early juveniles of roach Rutilus rutilus aged 11–28 days after hatching were first studied in long-term experiments (16 days). Two periods of the process of thermoselection—transient (selected temperature, up to 7–9 days after the beginning of the experiment) and final (final selected temperature, 8–10 days after the beginning of the experiment)—have been identified. The selection by larval roach of final selected temperature values occurs with use of the adaptation response of “excessive responding.” It was shown that correct determination of final selected temperature values for early juveniles of fish is possible only in long-term experiments (more than 7 days). The obtained results can be used during the analysis of behavior and distribution of larval roach under natural and experimental conditions.     

Indicators of innate immunity and oxidizing processes in the blood serum and liver in roach <Emphasis Type=Italic>Rutilus rutilus</Emphasis> L. from the Kuban River

Antimicrobial properties of the blood serum and the content of immune complexes, lipid peroxidation products, and antioxidants in the blood serum and liver have been analyzed in roach living in areas of the Kuban River with different levels of anthropogenic pollution. The relationship between the studied parameters and fish habitats is shown.     

The viability of the first generation roach (<Emphasis Type=Italic>Rutilus rutilus</Emphasis> L.), bream (<Emphasis Type=Italic>Abramis brama</Emphasis> L.), and blue bream (<Emphasis Type=Italic>Abramis ballerus</Emphasis> L.) hybrids at early stages of development

The viability of bream, roach, and blue bream F ₁hybrids at early stages of their development is analyzed. Viability is controlled according to parameters of the survival rate at stages from fertilized eggs to yearlings. During embryogenesis, significant stages (blastula—gastrula and hatching) are revealed by the amount of losses. The viability of hybrids of the first generation (compared to pure species) from the hatching stage and in the subsequent development constantly increases. At the stage of fingerlings, the viability of F ₁hybrids significantly exceeds that of pure species, which points to the heterozygous effect according to the parameters of hybrid survival for the first generation, which is absent in embryogenesis.     

<Emphasis Type=Italic>Gagea robusta</Emphasis> (Liliaceae), a new species from <Emphasis Type=Italic>Flora Iranica</Emphasis> area

A new species, endemic to the Flora Iranica area, Gagea robusta (Liliaceae) is described and illustrated. It differs from G. reticulata (Pall.) Schult. & Schult. f. in having a puberulent indumentum on the basal leaf and from G. setifolia Baker ex Aitch. in having a long neck (up to 12 cm long). Its ecology, distribution and conservation status are discussed.     

Growth rate during early life affects sexual differentiation in roach (<Emphasis Type="Italic">Rutilus rutilus</Emphasis>)

Many environmental factors have been shown to influence sex differentiation in fish, resulting in sex-biased populations, but the effects of growth rate have received limited attention. We conducted a controlled laboratory experiment in which growth rate and population density were manipulated in roach (Rutilus rutilus) during early development, and the subsequent effects on sex ratio determined. Significant differences in growth rate between fish populations were induced through provision of three different ration levels. In the slowest growing population there were fewer females compared within the fastest growing population (19% compared to 36% females), suggesting that in roach it may be more advantageous to become a small male than a small female when growth potential is limited. This may result from the fact that fecundity is limited by body size in female roach and that male roach are able to reproduce at a significantly smaller body size than females. In contrast, where roach were kept at different stocking densities, and there were no differences in growth rate, the subsequent proportion of females did not vary. Our data highlight the importance of controlling for growth rate in research on sexual differentiation in this species, notably when assessing for the effects of endocrine disrupting chemicals and other environmental factors, and have implications for fisheries management and aquaculture. The underlying mechanism for the influence of growth rate on sex differentiation has yet to be determined but is likely to have a strong endocrinological basis.     

The impact of hypomagnetic conditions and light deprivation on mitosis of germ cells and body length of prelarvae in roach (<Emphasis Type=Italic>Rutilus rutilus</Emphasis> L.)

The impact of light deprivation, geomagnetic deprivation, and the combination of these factors on the mitosis of germ cells in roach embryos and the body length of hatched prelarvae have been studied. It has been shown that geomagnetic deprivation leads to changes in the ratio of blastomeres that pass through initial and final phases of mitosis and the increase in the mitotic index of germ cells. The number of chromosomal abnormalities and body length of prelarvae change as well. An additive effect of the embryos exposure to the combination of light and geomagnetic deprivation is expressed as a significant increase in the number of aberrant mitosis and the body length of prelarvae.     

Mobility of individual roach <Emphasis Type="Italic">Rutilus rutilus</Emphasis> (L.) in three weir-fragmented Belgian rivers

Adult roach Rutilus rutilus (L.) (N = 24; 19.9–36.1 cm FL) from three highly fragmented Belgian rivers were tagged with surgically implanted radio transmitters. Their seasonal movements were observed from March to August 2004 (circum reproduction period) in river stretches delimited by two physical barriers. In the three rivers, roach displayed similar patterns of movements which were mainly influenced by the date of observation (movements increased in late April–May) and water temperature (travel distances were more important when water temperature ranged between 10°C and 14°C). Roach sometimes cleared physical obstacles. The mean distances travelled in each river were relatively short (max. 2.5 km) and mainly influenced by the length of the study reach, which was delimited by physical barriers.     

<Emphasis Type=Italic>Croton limae</Emphasis> (Euphorbiaceae), a new species of section <Emphasis Type=Italic>Argyroglossum</Emphasis> from northeastern Brazil

A new species in Croton section Argyroglossum from northeastern Brazil is described and illustrated. Croton limae was previously confused with C. tricolor and C. argyrophyllus, which are the most closely related species. Its geographic distribution is discussed and a key to distinguish these three related species is presented.     

High prevalence of zoonotic trematodes in roach (<Emphasis Type="Italic">Rutilus rutilus</Emphasis>) in the Gulf of Finland

The intention to increase roach (Rutilus rutilus) consumption is in focus for ecological and economic reasons in Finland. However, its safety as food has not been considered comprehensively. We collected and artificially digested 85 roach halves originating from the south-eastern coast of Finland, and found trematode metacercariae in 98.8% of the samples. Based on polymerase chain reaction (PCR) and sequencing of amplicons generated from the ITS2 gene region, zoonotic parasites of the family Opistorchiidae were identified as Pseudamphistomum truncatum and Metorchis bilis, and also non-zoonotic Holostephanus dubinini (family Cyathocotylidae) and Posthodiplostomum spp. (family Diplostomidae) were identified. The species identity of other trematodes found is currently being investigated. Mixed infections of several trematode species were common. The prevalence of morphologically identified zoonotic P. truncatum was 46%, and zoonotic M. bilis was found in one sequence sample. The high prevalence of zoonotic trematode metacercariae in roach from the Gulf of Finland is alarming. Only thoroughly cooked roach products can be recommended for human or animal consumption from the area.     

Efficient separation and purification of allophycocyanin from <Emphasis Type=Italic>Spirulina</Emphasis> (<Emphasis Type=Italic>Arthrospira</Emphasis>) <Emphasis Type=Italic>platensis</Emphasis>

Allophycocyanin (APC) is a minor component of phycobiliproteins in cyanobacteria and red algae. This paper describes a simple and inexpensive extracting method for isolating APC from Spirulina (Arthrospira) platensis with high efficiency. The crude phycobiliprotein extract was pretreated by ammonium sulfate fractionation. Then, by adding hydroxylapatite into crude phycobiliprotein extract dissolved in 20 mM phosphate buffer (pH 7.0), APC was selectively adsorbed by hydroxylapatite but C-phycocyanin (C-PC) was not. The hydroxylapatite was collected and APC was extracted from the crude phycobiliprotein extract. Then, the enriched APC was washed off from the hydroxylapatite using 100 mM phosphate buffer (pH 7.0). In this simple extracting method it was easy to remove C-PC and isolate APC in large amounts. The absorbance ratio A ₆₅₀/A ₂₈₀ of extracted APC reached 2.0. The recovery yield was 70%, representing 4.61 mg · g⁻¹ wet weight. The extracted APC could be further purified by a simple anion-exchange chromatography with a pH gradient from 5.6 to 4.0. The absorbance ratio A ₆₅₀/A ₂₈₀ of the purified APC reached 5.0, and the overall recovery yield was 43%, representing 2.83 mg · g⁻¹ wet weight. Its purity was confirmed by native polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate-PAGE.     

Comparative analysis of diurnal variations of the lipid composition in perch (<Emphasis Type=Italic>Perca fluviatilis</Emphasis> L.) and tyulka (<Emphasis Type=Italic>Clupeonella cultriventris</Emphasis> Nordmann) from the Rybinsk Reservoir pelagial

Diurnal variations of the total content and fractional composition of lipids in the organisms of underyearlings of indigenous (perch) and nonindigenous (tyulka) species have been analyzed. These fish species form the basis of feeding aggregations of young fish in the Rybinsk Reservoir pelagial. Stable interspecific differences in mean daily and hourly values of the content of total lipids and in the level of three fractions-phospholipids (PLs), cholesterol (CS), and triacylglycerols (TAGs)—have been determined. It is shown that the level of adipose reserves and the content of TAG in the tyulka are higher than in perch, while the contents of PL and CS are lower. Diurnal variations of the level of each of the three fractions in both fish species are similar, but the ranges of variations are wider in tyulka than in perch. Possible mechanisms for the regulation of lipid metabolism (including the participation of neuroendocrinal centers) and their similarity in young fish of different species upon adaptation to short-term changes in the environment have been discussed. It is suggested that the modern state of the zooplankton community in the Rybinsk Reservoir pelagial negatively affects the feeding of perch underyearlings and parameters of lipid metabolism in their organisms.