Impact of habitation conditions on metabolism in the muscles, liver, and gonads of different sex and age groups of bream

A A Payuta,E A Flerova

doi:10.15421/022133

Abstract

Impact of the factors of the aquatic environment is an inevitable aspect of the life of fish as poikilothermic animals and provokes responses in their organisms. The study focused on determining peculiarities in the composition of the metabolic products in the tissues of different age and sex groups of common bream Abramis brama (L.) depending on the living conditions in the water reservoirs of the Upper Volga. The fish were captured in the fattening period in summer and autumn, measured, weighed, identifying sex, maturity stage of the gonads and age. In the muscles, liver and gonads of bream, we analyzed the contents of water, dry matter, lipids, protein, ash and carbohydrates using the standard techniques. The contents of biochemical components in the organism of bream were to a higher degree determined by the peculiarities of the living conditions rather than sex and age of the individuals. In the muscles and liver of bream living in the conditions of increased water temperature and low concentration of oxygen, the concentrations of protein and ash were lower. In the same tissues of bream from the water bodies with high concentrations of pollutants in the water and benthic deposits, we found increased fat content. The muscles of male bream contained less protein and more carbohydrates than females and juvenile individuals, and the muscles of juveniles had less fat. The environmental factors had greater influence on the content of the metabolic products in the liver of bream than sex, and only females had higher ash content than males. The testes had more fat and less protein than the ovaries. During the transition of the gonads from maturity stage II to III, the contents of dry matter and lipids in them decreased. We determined that the environmental factors have stronger impact on biochemical parameters in the tissues of bream than age, because we found no general age patterns in the dynamics of biochemical components, except the liver, in which the highest content of organic compounds was found in individuals aged 6 to 10 years. Water heated by the Hydro Power Plant positively influenced the young bream, as indicated by higher content of metabolic products in individuals aged 5+ than older groups and bream from the surveyed water bodies. Monitoring of the physiological condition of bream focusing on the contents of metabolic products in the tissues may provide necessary data for successful regulation of bream populations in the water reservoirs of the Upper Volga.

Highlights

The patterns of the relationships between fish and abiotic and anthropogenic factors are among the problems studied within the scope of hydrobiology, because the effects of the environment such as fluctuation of water temperature, pH, oxygen, hydraulic regimes, pollutants and other are an inevitable aspect of life of fish as poikotherm animals (Shuter et al, 1989; Ali et al, 2005; Fang et al, 2010; Guiet et al, 2016; Santos et al, 2020)
Biochemical parameters of the muscles, the liver and gonads of bream living in different reservoirs of the Upper Volga to a greater degree depend on the complex impact of factors of the aquatic environment which are characteristic of each water body, rather than sex, stage of maturity of the gonads and age of specimens
Higher contents of protein and mineral substances in the muscles and liver of bream of the Gorky Reservoir were associated with more favourable living conditions in it compared with the Uglich and Ivankovo Reservoirs, in which we observed increased water temperature and low oxygen concentration that reduces the species diversity and populations of benthic animals, as well as negatively affecting the appetite of fish

Summary

Introduction

The patterns of the relationships between fish and abiotic and anthropogenic factors are among the problems studied within the scope of hydrobiology, because the effects of the environment such as fluctuation of water temperature, pH, oxygen, hydraulic regimes, pollutants and other are an inevitable aspect of life of fish as poikotherm animals (Shuter et al, 1989; Ali et al, 2005; Fang et al, 2010; Guiet et al, 2016; Santos et al, 2020). Indicators of metabolism attract great scientific interest, for their content may change due to the effects of various factors of the aquatic environment (Larsson et al, 1984; Lund et al, 2011; Collier et al, 2013; Filippov et al, 2017) This specificity of the organism of fish has developed in the process of the evolution to survive in changing conditions. Protein synthesis is associated with processes of growth, fish development, maturation of their sex glands, and its deficiency in the diet reduces or halts the growth and weight gain of fish because of intense expenditure of proteins to support the organism (Bano, 1977; Winfree & Stickney, 1981; Houlihan et al, 1994; Carter & Houlihan, 2001) Mineral substances, their ions and compounds are important components of hormones, enzymes and activators of enzymes, and participate in some metabolic processes and are essential in the organism (Lall, 2003; Fawole et al, 2007; Njinkoue et al, 2016). The resulting energy is used for mechanical work of muscles, biosynthesis, secretory function, and part of it disperses as heat (Shulman & Love, 1999; Dabrowski & Guderley, 2003; Lloret et al, 2014)

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