Size-weight Characteristics Research Articles

The finding of Unio pictorum (Linnaeus, 1758) (Bivalvia: Unionidae) in the Om’ River, Western Siberia

Juvenile and subadult individuals of the Painter’s mussel Unio pictorum (Linnaeus, 1788) were recorded in dredge samples from the Om’ River in the Omsk City (southwestern part of Western Siberia). Information on the size-weight characteristics of U. pictorum from the site, its abundance and biomass are given. Possible consequences of the introduction of this neobiotic species into aquatic ecosystems of the Irtysh River basin are discussed.

Обзор данных по биологии нельмы Stenodus leucichthys nelma (Pallas, 1773)

Nelma (Stenodus leucichthys nelma (Pallas, 1773)) is one of the biggest predators and a prominent representative of the whitefish family. It is a poorly studied valuable commercial species. The rate of growth and sexual maturation of this fish is very high compared to other whitefishes. Within the vast range of white salmon populations living in different geographical zones there can be found variability in meristic and size-weight characteristics. There are also differences in the time of sexual maturity of species in different rivers. Some negative limiting factors impact the nelma populations: pollution of water bodies, poaching, and transformation of the flows of large rivers (building the hydroelectric power stations, reservoirs, etc.). There have been presented the review of the published literature on nelma biology and the data of the proper research. Comparative analysis of the meristic, size-weight and physiological characteristics of nelma populations from different rivers within the geographical range has been made. From the review of available literary sources it follows that today the populations of nelma are characterized by a radical decline and rejuvenation of the spawning stock in almost all rivers of its habitat. There is found reducing the spawning areas of the species due to the regulation of the flows of large rivers. Studying biology and ecology of nelma as a valuable and endangered species is important today.

КОНЦЕНТРАЦИИ РТУТИ В МЫЩЦАХ РАЗНЫХ ВИДОВ РЫБ ИЗ ВОДОЕМОВ ЯРОСЛАВСКОЙ ОБЛАСТИ И ПРИЛЕГАЮЩИХ ТЕРРИТОРИЙ

Mercury (Hg) and its compounds, which pose a health risk to the population not engaged in hazardous industries, enter the human body mainly with food items. First of all, these are seafood, fish and canned fish. In this study, the concentrations of Hg in the muscles of different fish species from the water bodies of the Yaroslavl province were determined. The average values of mercury content range from 0.03 to 0.41 mg/kg wet weight. The recorded levels of mercury accumulation correspond or are close to the previously obtained values in the muscles of fish from freshwater reservoirs of the European part of Russia and European states. The species-specificity of the Hg accumulation process, its dependence on trophic specialization and size-weight characteristics of fish, as well as on the type of reservoir were noted. The regulatory standards established in the Russian Federation for the mercury content in the muscles of non-predatory (<0.3 mg/kg w.w.) and predatory (<0.6 mg/kg w.w.) fish species were exceeded in 0.3% and 16% of the studied non-predatory and predatory fish, respectively. Most specimens of predatory fish species with Hg concentrations in the muscles exceeding the accepted standards were recorded in small lakes with swampy catchment areas, less in reservoirs, and least of all – in medium-sized lakes. The maximum acceptable limits of mercury content in fish and fish products established in the Russian Federation correspond or are close to the current standards accepted in the countries of the European Community and the United States and WHO recommendations, although there is no detailed regulation by age groups and risk groups.

ВОЗРАСТНЫЕ ОСОБЕННОСТИ ПОКАЗАТЕЛЕЙ ОКИСЛИТЕЛЬНОГО СТРЕССА И СОДЕРЖАНИЯ АНТИОКСИДАНТОВ В ПЕЧЕНИ МОРСКОГО ЕРША SCORPAENA PORCUS ИЗ ПРИБРЕЖЬЯ БОЛЬШОГО КАВКАЗА

Comparative study of size-weight characteristics, lipid peroxidation (LPO) parameters and antioxidants content in the liver of marine scorpion fish Scorpaena porcus caught in the coastal waters of the Caucasus at the region of Shepsy village demonstrated age-related differences. The increase of the size and weight, the mass of the liver and gonads was observed in the elder fish, while the condition index varied less. Liver somatic index (LSI) increased in 2-3 years old animals, in the elder fish the growth of this parameters was slowly. Significant increase of gonadosomatic index (GSI) was noted in 4-5 years old animals, while the differences between 2 and 3 years groups were not observed. Lipid oxidation index and relative concentration of the ketodiens did not vary in age. Content of dien conjugates in hepatic lipids was significantly lower (p<0,001) in 3-4 years old fish as compared with the parameters of other studied age groups. TBA-reactive products concentration in the hepatic lipids increased with age and the highest values were observed in 5-6 years old animals. Significant correlation was shown between the content of TBA-reactive products in fish liver and the animals age (r = 0,88, p<0,05), while between the other studied parameters and fish age no significant relations were noted. Vitamin A and carotenoids concentration did not vary with age, however the tendency to increase was observed in 4 years old fish. The reasons of the growth of reactive oxygen species processes (ROS) and the increase of lipid peroxidation compounds concentration can be connected with the decrease of the defense mechanisms of the organism and the damage biomolecules, genetic defects, cell pathologies, tissues and organs and accumulation of xenobiotics in the fish, which impact the organism, accompanied with the oxidative stress. In elder animals the concentration of toxic substances is greater, and together with the decrease of the defense systems the cumulative toxic effect becomes mote considarable. The obtained results in this study provide the additional information for the understanding of the mechanisms of ROS theory of aging at the case of vertebrates of the natural populations. Further investigations could be strengthening to the study the role of endo- and exogenous conditions, modulating the age processes in aquatic organisms, which is important for the ontogenesis mechanisms and they dependence on natural and anthropogenic factors.

Effect of an Aquaculture Freshwater Body on the Behavior and Growth of European Perch

The spatial structure of the population of European perch is transformed and the behavior, diet, and size–weight characteristics of perch individuals change in aquaculture conditions. Instead of an individual diffuse behavior, fish form large aggregations in a cage zone. Active consumption of high-calorie trout feed leads to a reduction in the proportion of natural food items, in particular, zoobenthos. The size and weight of individuals significantly increase. The high density of the fish community in a small part of the water area allows older perch to more successfully hunt, thereby leading to a naturally untypical acceleration of their growth rates.

Range Expansion of the Caspian Invader Leech Archaeobdella esmonti Grimm, 1876 (Annelida: Clitellata: Hirudinida) in the Upper Volga Basin

A species of Caspian fauna, leech Archaeobdella esmonti, introduced earlier into most reservoirs of the Volga cascade, was recorded for the first time in the Uglich Reservoir in summer 2017. In 2009, A. esmonti was first detected in the Rybinsk Reservoir, where it was successfully established by 2015, and its occurrence frequency increased to 50%. The quantitative and size-weight characteristics of the species in the Rybinsk Reservoir are presented in this paper.

ВЛИЯНИЕ ОБЪЕМА СТОКА И РЕЖИМА ПОЛОВОДЬЯ НА КАЧЕСТВЕННЫЕ ХАРАКТЕРИСТИКИ МОЛОДИ ЛЕЩА (ABRAMIS BRAMAORIENTALIS L.) В ВОСТОЧНЫХ И ЗАПАДНЫХ ЧАСТЯХ ДЕЛЬТЫ РЕКИ ВОЛГИ

The paper presents the assessment results of the influence of hydrological conditions on the qualitative characteristics of bream juveniles in the Volga delta. The influence of factors (volume, hydrological characteristics of spring flood, temperature conditions) on the spawning periods of producers, duration of feeding of juveniles at spawning grounds, including viable ones, at the end of the hollow period has been traced. There have been presented the comparative data on the age, distribution and qualitative composition of larvae and juveniles obtained in the course of the research works at spawning grounds in different regions of the lower reaches of the Volga River in 2011-2017. The most favorable conditions for feeding on young bream have been found to form in the high-water years (2013 and 2016) and in the mid-water year (2017). Years 2011 and 2015 became critical for natural reproduction; years 2012 and 2014 were unfavorable. The highest size-weight characteristics of bream juveniles were observed by the end of the hollow period in the east of the delta in the arid and middle water years, and in high-water years they were found in the Volga-Akhtuba floodplain. The qualitative characteristics of bream in the east in low-water years were maximum in the upper zone, minimal - in the middle zone, in the western spawning grounds there was observed a reverse situation. In high-water years the highest values of bream juvenile size-weight parameters were observed in the middle zone in the east of the delta. In the mid-water year (2017) in the eastern part of the delta the maximum feeding results were observed in the lower zone, and in the spawning grounds of the western delta - in the middle zone. By the end of the feeding period in high-water years practically all bream juveniles (98.4%) reached the viable stage of development, and in arid years only 28.4% of bream juveniles reached the stage.

ВЛИЯНИЕ ДОБАВОК В КОРМ ВИТАМИНОВ ГРУППЫ B НА ЭМБРИОНАЛЬНОЕ И РАННЕЕ ПОСТЭМБРИОНАЛЬНОЕ РАЗВИТИЕ КОШАЧЬЕЙ АКУЛЫ В ЭКСПЕРИМЕНТАЛЬНЫХ УСЛОВИЯХ

The article describes the problem of optimization of feeding cat sharks in the aquarium environment at the exposition of the Museum of the World Ocean in relation to the loss of vitamins in the course of freezing fish and squids that make a part of shark feed. In the process of studying the influence of added to the feed vitamins of B group (thiamine, pyridoxine, riboflavin, cyanocobalamin) onto cat shark organism at different stages of ontogenesis there have been found a positive results: improvement of the physiological state of cat shark juveniles and acceleration of the terms of eggs incubation. To exclude possible bacterial diseases the experiment was conducted after termination of microbiological study that revealed presence of opportunistic pathogenic bacteria causing red spot disease in cat sharks under violation of living conditions. In the course of the experiment there were studied size-weight characteristics of cat shark juveniles, taken measuring of eggs and juvenile species, searched various anomalies in eggs. There have been recorded the indices of the internal organs of cat shark juveniles, namely heart, spleen and liver indexes, erythrocytes number and hemoglobin concentration in blood using Foulton and Clark fatness factors. According to the results of the study, it has been stated that sharks taking feed with added vitamins successfully adapt to environmental conditions and their offsprings less suffer from factors of negative impact. It has been inferred that B vitamins has a positive effect on growing cat sharks in the aquarium environment.

REPRODUCTION OF THE BROWN TROUT (SALMO TRUTTA L.) AND ATLANTIC SALMON (SALMO SALAR L.) IN SMALL RIVERS (WHITE SEA DRAINAGE BASIN)

Some aspects of the reproduction of salmonid fish in the small rivers Ol’khovka and Krivoy Ruchey (White Sea drainage basin, Tersky coast of the Kola peninsula), including downstream migration of brown trout and atlantic salmon smolts, as well as the distribution of juveniles of these species across these watercourses have been studied. Data are provided on the size-weight characteristics of the parr and smolts of both species, their sex and age composition. Correlation was revealed between the progress of downstream migration and mean daily water temperature. It was established that small rivers with mean annual discharge below 1.5 m 3 /s harbor spawning of not only brown trout but also atlantic salmon. although the number of spawners is low (less than 20 pairs), this nevertheless contributes to enlargement of the species biodiversity. It should be borne in mind that there are hundreds of small rivers in the White Sea drainage basin, which collectively make a significant contribution to the abundance of both brown trout and atlantic salmon. The approach to surveys and studies of small watercourses should therefore be revised.

Impact of heron (Ardea cinerea L. and A. alba L.) habitat on coastal juvenile fish assemblages in Rybinsk Reservoir

It has been determined that the stocking density of juvenile fish in an open reservoir shallow-water site in the heronry area in the nesting period is higher than that in the reference site. The juvenile roach Rutilus rutilus L., which is one of the dominant species, in the bird impact zone significantly differs in higher values for both the size–weight characteristics and the body weight-growth rates. The habitat-dependent phenotypic differences in various biotopic assemblages of the juvenile fish are revealed. It has been proven that the environmental impact of the heron-colony life activities on the fish populations in the reservoir shallow-water site is temporary, which is limited by the bird-nesting season.

ЧИСЛЕННОСТЬ И КАЧЕСТВЕННЫЕ ХАРАКТЕРИСТИКИ МАЛЬКОВ РЫБ НА МЕЛКОВОДНОМ УСТЬЕВОМ ВЗМОРЬЕ РЕКИ ВОЛГИ В ЛЕТНЕ-ОСЕННИЙ ПЕРИОД 2012 ГОДА

Shallow coastal waters of the Volga river is a flooded feeding area for fish juveniles of nonmigratory fish species. There takes place annual downstream migration of fluvial anadromous fish species from spawning grounds of the Volga river to the Northern Caspian Sea. The most important factors determining the number and qualitative characteristics of fry fishes are the level of the Caspian Sea (currently having a tendency to the lowering), hydrological and thermal regimes of the Volga river. Researches were carried out in definite periods of time. In the summer-autumn period of 2012 fry fishes were presented by 19 species (13 of them were commercial species), which belonged to 9 families. The article gives data on all the commercial fish species. In the first decade of July the maximum number of fry fish was registered in the western part of the Volga outfall offshore - in box 247 (19.86 mln specimens/km2), in the eastern part - in box 142 (20.4 mln specimens/km2). The most populous were roach, red-eye, silver bream and bream; size-weight characteristics were better in the areas remoted from the Volga delta. In the third decade of July the quantitative indicators of fry fish on these areas decreased, size-weight characteristics greatly increased. In the second decade of October in the western part of the seaside there were registered increased pre-wintering concentrations of fish juveniles, their qualitative indicators increased, which is evidence to favorable feeding conditions in 2012.

Some morphological features of fry of roach Rutilus rutilus (Cyprinidae, Cypriniformes) after separate and combined exposure of embryos to magnetic field and elevated temperature

Separate and combined exposure of roach Rutilus rutilus embryos during the first 38 h after fertilization to magnetic field (500 Hz, 1.4–1.6 µT) and elevated temperature (23°?) causes morphological responses: decrease in mean values of length and weight of the body, increase in the number of vertebrae, and increase in the number of vertebral anomalies and morphological diversity of vertebral phenotypes. Size–weight characteristics and the number of vertebrae in underyearlings are related to the development of anomalies in its backbone. A method for counting of vertebrae in fish with backbone malformations is suggested.

Fertility and embryonic mortality level of the Japanese mitten crab Eriocheir japonica (Crustacea: Decapoda: Varunidae) in Primorye

Reproductive biology of the Japanese mitten crab Eriocheir japonica (de Haan, 1835) was studied in the northern part of its habitat. It was revealed that E. japonica from the water bodies of Primorye, in contrast to crabs in the central part of the habitat on the Japanese Islands, lays fewer eggs in the first clutch, does not have direct dependence between the size-weight characteristics of females and the number of eggs in the third clutch, and shows higher level of embryonic mortality. The loss of eggs during the embryonic period in each of three sequentially laid clutches was 16, 34, and 52%, respectively (28% in total during the period of reproduction). Fecundity was approximately 43%. It was registered that the specifics of reproductive biology of E. japonica (monocyclicity, prolonged period of reproduction, portion spawning, indirect embryonic development, high fertility, relatively small and yolk enriched eggs, pelagic planktotrophic larva, high level of energy costs on reproduction, egg bearing on the pleopods, high level of embryonic mortality), an intermediate strategist, is in a good agreement with its life strategy, thereby enabling this species to realize its reproductive potential in the northern part of the habitat.

Size–weight characteristics of the late instar larvae of chironomids (Diptera, Chironomidae) in Lake Vishtynetskoye

The extreme values of the body length, wet weight, and head capsule width, as well as the mean wet weights of the third and fourth instar larvae, are presented for 53 of the most widespread species and groups of chironomids in Lake Vishtynetskoye.

Coregonus lavaretus lavaretus (L.) (Coregonidae) in Babinskaya Imandra (Imandra Lake)

This study investigated changes in the structure of catches and growth rate of whitefish in the background regions of Lake Imandra (Babinskaya Imandra) in different periods of the lake’s transformation (1996–1997 and 2011). A reduction in the number of age groups with a reliable increase in the observed size-weight characteristics and back-calculation of fish lengths (TL) has been found. The increase of growth rate, in turn, has led to the naturally earlier achievement of optimal linear dimensions of the first spawning fish and to an earlier age of entry of males and females in the spawning population. No effect of whitefish puberty on the growth rate has been shown.

The effect of a typical magnetic storm on mitosis in the embryo cells and the length and weight of roach (Rutilus rutilus L.) prolarvae

The action of the tested variants of a typical magnetic storm (MS) has a biological effect on cellular and organismal levels in the prolarva stage. The impact of this environmental factor leads to increased mitotic activity in blastocysts, it can trigger the early hatching of embryos, and it has no negative impact on the size-weight characteristics of free embryos.

FEATURES OF PUMPKIN AND SQUASH GROWING FOR MECHANICAL SEPARATION OF SEEDS

The features of growing of pumpkin and squash for seed production in the conditions of the Moscow region are shown. The size-weight characteristics of grown fruits and seeds of pumpkin crops in order to use these indicators in machine seeds selection are shown.

The lipid status and feeding habits of yearlings of mykiss Parasalmo mykiss and coho salmon Oncorhynchus kisutch in autumn

Juveniles of coho salmon Oncorhynchus kisutch and mykiss Parasalmo mykiss at the age 1 + (yearlings) are differentiated by the content of different fractions of lipids (the lipid status), feeding habits, and by size-weight characteristics even eight months prior to smoltification. The juveniles of coho salmon and mykiss with high lipid status consume more calorific food items and, as a rule, have higher (on average) body length and weight. The juveniles with low lipid status consume less calorific organisms and have lower body length and weight. It is supposed that a considerable part of juveniles with high lipid status will migrate seaward the next year. The role of feeding habits in formation of this differentiation and, accordingly, in determination of timing of smoltification are discussed.

Influence of abiotic factors on the structure of the population of the brown alga Fucus vesiculosus in East Murman (Barents Sea)

The peculiarities of the structure of the population of the brown alga Fucus vesiculosus in East Murman at different combinations of abiotic factors were studied. Salinity below 10‰ and high surf activity reduced the average life span of the plants (to 1 year) and caused a significant predominance of female specimens (60–90% of the fertile specimens). The proportion of female specimens increased with age. The greatest average age (3 branchings) and the highest survival of F. vesiculosus occurred in the wave-protected parts of bays. The distribution of F. vesiculosus was related to water movement intensity, salinity, and substrate type. The size-weight characteristics of F. vesiculosus thalli were decreased during maximum salinity fluctuations. The optimal conditions for this species were those existing on a weakly protected shore with short-term fluctuations of salinity (24–25‰).

Effect of polarization and coherence of low-intensity optical radiation on fish embryos

We have shown that brief exposure of sturgeon embryos (fertilized roe) in the organogenesis stage to low-intensity radiation in the visible region of the spectrum can have a long-term effect on embryonic and post-embryonic development of the fish, detectable 50 days after the irradiation procedure. The biological effects (size-weight characteristics and hardiness parameters of the fish relative to unfavorable habitat conditions) induced by linearly polarized emission from a monochromatic laser source (helium-neon laser, λ = 632.8 nm, Δλ ≈ 0.02 nm) and a quasi-monochromatic light-emitting diode (LED) source (maximum in emission spectrum λ = 631 nm, Δ λ = 15 nm) are practically the same. Going to broadband linearly polarized radiation (λ = 420–800 nm) is accompanied by a decrease in the biological effect. From the results of studies of the effect on embryos from linearly polarized and unpolarized radiation from an LED source and also the effect of linearly polarized, circularly polarized, and unpolarized radiation from a helium-neon laser, we concluded that the type of polarization is of critical importance in realization of the biological effect of radiation. In this case, the maximum stimulating effect (on the size×weight characteristics and the hardiness parameters for juvenile fish) is observed on exposure to linearly polarized radiation; the photobiological effect induced in the same dose range by light with natural polarization (i.e., unpolarized) is significantly less pronounced; the stimulating effect of circularly polarized radiation occupies an intermediate position. Based on the presented data and also on data obtained previously, we conclude that among the resonant and nonresonant photophysical processes (orientational effect of light, effect of gradient forces, dipole-dipole interactions, thermooptic processes) capable of inducing photobiological effects dependent on such laser-specific characteristics as polarization and coherence, the determining influence in the processes studied in this work comes from the orientational effect of light and dipole×dipole interactions. And the orientational effect can appear for anisotropic media with liquid-crystal type ordering (especially domains in membranes and multiple-enzyme complexes) both under conditions when there is no resonant absorption and for weakly absorbing structures, and can initiate a change in their conformations and accordingly their functional characteristics.