The current state of molecular genetic research on the taxonomic diversity of the enteric microbiota of Siberian fish

Author(s):  
Elena Nikolaevna Kashinskaya ◽  
Evgeniy Petrovich Simonov ◽  
Mikhail Maryanovich Solovyev

This paper presents the current state of research on the intestinal microbiota of fish of different ecological groups from water bodies of West and East Siberia. The present study focused on the gut bacterial diversity of 16 species/forms of fish (due to intricate taxonomical position of whitefish from Teletskoye Lake) inhabiting Chany Lake (Novosibirsk oblast), Teletskoye Lake (Altai Republic), Baikal Lake and other water bodies of East Siberia using molecular genetic methods. The analysis of the conducted studies shows the main features of gut bacterial communities in the digestive tract of fish and to better understand the features of the functioning of aquatic ecosystems in Siberia. In all studied fish (except for Lena grayling and Baikal omul), regardless of their habitat, taxonomy, digestive system structure (presence or absence of stomach and pyloric caeca) and feeding habits, bacteria of all four phyla (Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria) were found among the dominants. Such differences can also be explained by sample preparation techniques before sequencing that researchers may apply. Also, the uncultivated microbiota such as Pseudoalteromonadaceae (Lake Chany), Comamonadaceae and Bacillaceae (whitefish from Lake Teletskoye) and Rhodobacteraceae (Baikal omul and whitefish) were often found among the dominant bacterial taxa in the digestive tract of the most studied fish. Moreover, the data focused on the structure of gut bacterial community of fish will be useful for the development of aquaculture industry in the region, since the information makes it possible to identify pathogenic, opportunistic, and probiotic bacteria in aquatic ecosystems.

Diversity ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 112
Author(s):  
Eftychia Tzafesta ◽  
Francesco Zangaro ◽  
Valeria Specchia ◽  
Maurizio Pinna

The loss of aquatic biodiversity is increasing at a rapid rate globally. There is a worldwide effort to protect, preserve and restore aquatic ecosystems. For efficient biodiversity monitoring and reliable management tools, comprehensive biodiversity data are required. The abundance and species diversity of benthic macroinvertebrates are commonly used as indicators of the aquatic ecosystem condition. Currently, macroinvertebrate species biodiversity assessment is based on morpho-taxonomy, which could be enhanced by recent advances in DNA-based tools for species identification. In particular, DNA metabarcoding has the potential to identify simultaneously many different taxa in a pool of species and to improve aquatic biomonitoring significantly, especially for indicator species. This review is focused on the current state of DNA-based aquatic biomonitoring using benthic macroinvertebrates in the Mediterranean region.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Bhaskara Canan ◽  
Wallace Silva do Nascimento ◽  
Naisandra Bezerra da Silva ◽  
Sathyabama Chellappa

This study investigated the morphohistology of the digestive tract and the mean intestinal coefficient of the damsel fishStegastes fuscuscaptured from the tidal pools of Northeastern Brazil. The wall of the digestive tract ofS. fuscusis composed of the tunica mucosa, tunica muscularis, and tunica serosa. The esophagus is short with sphincter and thick distensible wall with longitudinally folded mucosa. Mucous glands are predominant, and the muscular layer of the esophagus presented striated fibers all along its extension. The transition region close to the stomach shows plain and striated muscular fibers. Between the stomach and intestine, there are three pyloric caeca. The intestine is long and thin with four folds around the stomach. The anterior intestine presents folds similar to those of pyloric caeca. The estimated mean intestinal coefficient and characteristics of the digestive system ofS. fuscuspresent morphological adequacy for both herbivorous and omnivorous feeding habits.


2021 ◽  
Vol 27 (1) ◽  
pp. 6-14
Author(s):  
V. Zaslonovsky ◽  
◽  
N. Sharapov ◽  
M. Bosov ◽  
◽  
...  

The paper is devoted to the development of proposals concerning the improvement of surface water bodies and the appointment of target indicators of the natural waters’ quality. The paper considers a variety of problems of preserving, restoring and improving the quality of natural surface waters: from regional features of the formation of natural water composition, to differences in the requirements for the quality of water consumed. The object of the study is the qualitative indicators of the waters of natural water bodies, and the subject of the study is the methodological approaches to the normalization of these indicators. The purpose of the work is to identify the main shortcomings in the domestic system of rationing the quality of natural waters, and to form appropriate proposals. For this purpose, the following tasks were set and solved: to review the methodological approaches to assessing and rationing the quality of natural waters used in some foreign countries and in the Russian Federation, to identify the main causes and shortcomings; to make proposals for improving the current system of water quality rationing. The result of this work is the conclusions about the lack of impact of the strategy operating in Russia in the development of schemes of complex use and protection of water objects, standards of permissible impact on water bodies, the appointment of permissible discharge limits in terms of maintaining and improving the water quality of natural water bodies. The reasons that led to this are indicated. The necessity of taking into account, in addition to the physical and chemical composition, also hydrobiological parameters is shown. It is concluded that instead of fisheries management standards, environmental standards should serve as the basis for target indicators of water quality of natural water bodies, which determine the well-being of humans and the stable functioning of aquatic ecosystems, taking into account regional factors. Proposals were made to adjust the methodological approaches to the implementation of this strategy. According to the authors, these proposals will speed up the solution of the main objectives of the strategy – the ecological improvement of water bodies, the preservation of unique aquatic ecosystems and the environmentally safe development of territories that previously experienced relatively small anthropogenic impacts (Eastern Siberia and the Far East)


Author(s):  
Grace Madanire-Moyo ◽  
Annemariè Avenant-Oldewage

Cestodes are parasitic flatworms that live in the digestive tract of vertebrates as adults and often in the liver, muscle, haemocoel, mesentery and brain of various animals as larval stages. To identify the cestodes infecting Clarias gariepinus Burchell, 1822 (sharptooth catfish) in the Vaal Dam, a total of 45 host specimens were collected with the aid of gill nets between October 2011, January and April 2012. The fish were sacrificed and examined for cestode parasites. Two adult cestodes, Tetracampos ciliotheca Wedl, 1861 (prevalence 86.7%, mean intensity = 15, n = 45) and Proteocephalus glanduligerus (Janicki, 1928) (prevalence 51.1%, mean intensity = 5, n = 45) were found in the intestines of the catfish. Both T. ciliotheca and P. glanduligerus are new locality records. There were statistically insignificant differences in the infection of the male and female C. gariepinu. Fish with standard length ranging from 40 cm – 54 cm (≥ 3 years) had the highest prevalence and mean intensity while those ranging from 10 cm – 24 cm (< 1 year) had the lowest prevalence and mean intensity for both cestodes. The study highlights the importance of changing feeding habits of C. gariepinus with age on the prevalence and mean intensity of the two gastrointestinal cestode parasites.


2018 ◽  
Vol 29 (2) ◽  
Author(s):  
N. O. Roshchyna

In this article, the current and former distribution of higher aquatic vegetation has been analyzed for floodplain lakes, arenas lakes and third terraces lakes in the valleys of large and medium North-Steppe Dnieper rivers. The article is devoted to the current state analysis of the higher aquatic vegetation at North-Steppe Dnieper lakes, its dynamics over a long-term period, as well as the determination of the nature and extent of anthropogenic-climatic changes in vegetation. Anthropogenic influence is a major threat to the development and functioning of most aquatic ecosystems. Since the twentieth century, it has been intensified by trends to long-term climate changes, which are also largely result of human activity. Increasing temperature of the winter season does not contribute to snow accumulation. Reduction of snow accumulation (frequent thaws during the winter), regulation of river flow (formation of a reservoirs cascade and ponds) and accumulation of melt water in artificial reservoirs led to the smoothing of the peak of the spring flood. Thus, the factor that provided spring washing of floodplain lakes, limited their overgrowing by air-water vegetation and their waterlogging disappeared. The anthropogenic factors that influence negatively include: intensification of agriculture, plowing of coastal areas, unreasonable land reclamation, overgrazing, development of transport and engineering infrastructure, urbanization, recreation, and chemical pollution. The presented data was obtained on the basis of processing our own research materials of 2009–2018 and literary and archival materials analysis (the herbarium of the Dnipropetrovs’k National University and the archive of the Research Institute of Biology). Natural Northern Steppe Dnieper lakes are located mainly in river valleys, so the study area was conventionally divided into sections: the large river valley (Dnieper) and the middle rivers valleys (Samara and Orel). Three ecological groups of macrophytes were reviewed and compared: hydatofites (submerged species), pleistophytes (species with floating leaves) and helophytes (air-water species). The vegetation of Dnieper floodplain lakes practically did not change for all three formation groups. The number of immersed plants communities within the floodplains of medium-sized rivers has decreased by three. The pleistophytes and helophytes associations decreased to fragments of associations. The lakes vegetation within the sandy Dnieper terrace practically did not change for all three formation groups. The submerged lakes plants associations within the sandy medium-sized rivers terraces have been reduced by two. As part of the lakes vegetation on the Dnipro saline terraces, fragments of associations of the two species are considered extinct. A new association of southern adventive species Ruppia maritima L. has appeared within the limits of the middle rivers saline terrace. Changes in higher aquatic vegetation are characteristic of all types of lakes. Changes occur in the direction of crowding out higher aquatic vegetation communities by airborne plant communities. The consequence of the anthropogenic-climatic transformation of aquatic ecosystems is increased mineralization, siltation, and, as a result, intensive overgrowing of lakes by aboriginal and adventive species with a wide ecological amplitude (replacement of sensitive to environmental changes species).


2020 ◽  
Vol 21 (S11) ◽  
Author(s):  
Vitaly A. Likhoshvai ◽  
Vladimir P. Golubyatnikov ◽  
Tamara M. Khlebodarova

Abstract Background The regulatory feedback loops that present in structural and functional organization of molecular-genetic systems and the phenomenon of the regulatory signal delay, a time period between the moment of signal reception and its implementation, provide natural conditions for complicated dynamic regimes in these systems. The delay phenomenon at the intracellular level is a consequence of the matrix principle of data transmission, implemented through the rather complex processes of transcription and translation.However, the rules of the influence of system structure on system dynamics are not clearly understood. Knowledge of these rules is particularly important for construction of synthetic gene networks with predetermined properties. Results We study dynamical properties of models of simplest circular gene networks regulated by negative feedback mechanisms. We have shown existence and stability of oscillating trajectories (cycles) in these models. Two algorithms of construction and localization of these cycles have been proposed. For one of these models, we have solved an inverse problem of parameters identification. Conclusions The modeling results demonstrate that non-stationary dynamics in the models of circular gene networks with negative feedback loops is achieved by a high degree of non-linearity of the mechanism of the autorepressor influence on its own expression, by the presence of regulatory signal delay, the value of which must exceed a certain critical value, and transcription/translation should be initiated from a sufficiently strong promoter/Shine-Dalgarno site. We believe that the identified patterns are key elements of the oscillating construction design.


2015 ◽  
Vol 12 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Md. Abdur Razzaq Joadder

Food and feeding habits of fishes have a great significance in aquaculture practices. It helps to select such species of fishes for culture which will utilize all the available potential food of the water bodies without much competition with one another but will live in association with other fishes. This paper deals with the feeding intensity and food habits of L. bata . Food and feeding habit of freshwater minor carp Labeo bata (120 to 250 mm total length) were studied. The fish is a herbivore, feeding mainly on algae (22.32 %), higher plant parts (31.26 %), protozoans (7.42 %), crustaceans (15.33 %), insects (3.56 %), muds, sand, debris and detritus (16.32 %) and unidentified food materials (3.99%).Journal of Science Foundation, 2014;12(1):7-15


Kardiologiia ◽  
2018 ◽  
Vol 58 (11) ◽  
pp. 24-34 ◽  
Author(s):  
E. Yu. Andreenko ◽  
I. S. Yavelov ◽  
М. М. Loukianov ◽  
A. N. Vernohaeva ◽  
O. M. Drapkina ◽  
...  

In addition to conventional risk factors in young patients with ischemic heart disease (IHD) numerous other risk factors including genetics play an important role in its causation. Molecular genetic testing is recommended for the detection of monogenic diseases with a high risk of developing IHD, such as familial hypercholesterolemia. In majority ofyoung patients, the first manifestation of IHD is an acute coronary syndrome. Young patients with IHD more often have normal coronary arteries or single-vessel coronary disease, and in up to 20% of them cause of myocardial ischemia is not related to atherosclerosis. In general, young patients with IHD have better prognosis. However, there are sex differences in IHD outcomes the prognosis of patients with premature IHD and reason for this is still unclear.


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