Juvenile Sturgeon Research Articles

Technological factors in the cultivation of sterlet sturgeon planting material in a recirculation aquaculture system

Recently, it has not been possible to engage in natural reproduction of sturgeons in Dagestan, because the spawning rivers Terek and Sulak are regulated, and the passage to the spawning grounds is completely closed by dams. There is only one way out for the restoration of sturgeon stocks it is artificial reproduction through industrialization and the creation of complex, closed regulated fish farms that can function both in the form of small fish farms and in the form of large holdings. The purpose of the work was to study technological factors in the cultivation of sterlet sturgeon planting material in a recirculation aquaculture system. The object of the study was a population of sterlet sturgeon (Asirepseg ruthenus Linnaeus, 1758) – a freshwater fish species of the sturgeon family. The study material was normally pigmented and albino (colored) sterlet with an average initial weight of 60 g. Under the conditions of the Republic of Dagestan studies have been carried out to establish the influence of a complex of biotic and abiotic factors (temperature, oxygen, planting density, feed grade, meat and bone attractant, probiotic Subtilis) on the growth, morphometric indicators and survival of juvenile sterlet sturgeon in the recirculation aquaculture system. The fish-breeding and biological characteristics of pigmented and albino sterlet have been given. It has been established that the design features of the recirculation aquaculture system did not allow to meet the biological needs of sterlet in water. The flow rate of water entering fish tanks was limited to 10 l/min per 1 m³, which provided a water change in 1 hour 40 minutes at a standard of 20–60 minutes. The optimal planting density of sterlet with an initial body weight of 58–64 g under conditions of limited water supply (10 l/min/m³) was the density of 250 pcs. /m³. The effectiveness of using two formulations of compound feed when growing both normally pigmented fish and their albinos showed that the highest fish-breeding indicators were obtained in normally pigmented sterlet when feeding with Sturgeon Grower No. 4 (47/13). The economic effect amounted to 373,5 rubles/m³. In albinos, the highest fish-breeding indicators were obtained when feeding productional feed Sturgeon grower 46/18 with. The economic effect was 285,0 rubles/m³.

Temperature Factor in the Cultivation of Juvenile Anadromous Sturgeons in Warm-Water Farms

In many fish farms using the warm waters of energy facilities, for long periods, the water temperature can significantly exceed the temperature range favorable for fish rearing. Effective cultivation of juvenile sturgeons in these conditions is a pressing production issue. The purpose of the study is to determine the optimal heat costs for the existing technological stages of growing juvenile sturgeons based on the assessment of the temperature conditions of warm-water farms and their comparison

Study on activity of different tissues from juvenile Yangtze sturgeon in the early post-mortem period.

Study on activity of different tissues from juvenile Yangtze sturgeon in the early post-mortem period.

Experience of using dry biomass of methanotrophic bacteria in the enrichment of artificial feeds for Siberian sturgeon juveniles of the Ob population

The article discusses the results of a study on the enrichment of artificial feeds with dry biomass of methanotrophic bacteria of 10 and 20% concentration and fatty acids (treatment “Arfit”, linseed oil). The data on the increase in body length and weight, the survival rate of Siberian sturgeon juveniles, depending on the applied preparations introduced, are presented. The best results were obtained when 10% of dry biomass of methanotrophic bacteria and HUFA were added to the feed (acceleration of weight growth by 44%, linear growth by 38%). The presented results are aimed at developing some elements of the technology for enriching artificial feeds with microbiosynthesis products.

Specific features of rearing of the Russian sturgeon juveniles in the Don Sturgeon hatchery in 2021

Specific features of rearing of the Russian sturgeon juveniles in the Don Sturgeon hatchery in 2021

Effects of variation of holding temperature on physiological and biochemical parameters of juvenile sturgeon fish in the conditions of industrial breeding

Below are presented the results of physiological stress (sudden temperature variations) affecting the physiological and biochemical parameters of juvenile sturgeon fish (sterlet and Siberian sturgeon) in the conditions of industrial breeding. They show that the temperature variations in the range of ±15 °С at the rate of 5 °С/hour towards temperature decrease are reversible physiological stress for physiologically healthy starving juvenile sturgeons, with which the species cope well if corresponding adaptation mechanisms are used (100 % survival rate). According to the examined physiological and biochemical parameters, the temperature variation towards decrease has its impact on the respiratory frequency (if the temperature decreases by 5 °С during the first hour of exposure, it increases by 30 % from the initial frequency; in three hours of exposure it decreases by 15 % from the initial frequency if the temperature decreases by 15 °С) and blood glucose level which increases by 15, 30 and 50 % every hour of exposure. The same temperature variations towards increase lead to irreversible physiological changes accompanied by the manifestations of acute stress reaction and death of juvenile fish depending on the severity and duration of temperature stress. During the first hour of exposure, the respiratory frequency increases twice, during the second hour it increases 2.5-fold, and 3-fold during the third hour. Blood glucose level increases by 10% during the first hour, twice during the second hour, 3-fold during the third hour from the initial level. Blood lactate level increases 5-fold from the initial level between the second and the third hour of exposure. Acute stress reaction beyond the adaptive capabilities manifests itself as a drop in fish survival rate in the second or the third hour of temperature increase, from 80-90% to 0% of general fish quantity in the experiment respectively.

Результаты выращивания молоди ленского осетра (Acipenser baerii Brandt) в УЗВ на различных рецептурах кормов

The effect of Aller Arrow S and Aller Trident S formula feeds on the growth, development and accumulation of fat in the muscles of Lena sturgeon juveniles raised in the conditions of ultrasonic testing for a repair herd was studied. The obtained results of cultivation indicate the effectiveness of the use of Aller Arrow feeds to reduce fat accumulation. It is shown that production feeds with a fat content of 14% and a higher (by 4%) energy-protein ratio contribute to an increase in the fatness coefficient and a decrease in the progonicity index, their use leads to an increase in liver weight by 48.5% (p≥0.05), and the gastrointestinal tract by 5.6%. The ratio of connective and adipose tissues, the density of muscle fibers indicates a more intensive accumulation of fat when using Aller Trident S, which indirectly indicates a higher energy (gastronomic) value of meat, due to an increase in its caloric content. According to the average final mass, mass accumulation coefficient, yield and growth of ichthyomass, relative growth rate, average daily growth, the best results were obtained in juveniles raised on production feed, the economic effect was 400 rubles/m3 of the pool.

Three Gorges Dam alters the footprint of particulate heavy metals in the Yangtze Estuary

Two scenarios were selected to simulate the situation before the closure of the Three Gorges Dam (TGD) in 1996 (Scenario 1) and after the completion of the Three Gorges Project in 2010 (Scenario 2). A modified polar co-ordinated segmented quantification method was proposed to quantify the heavy metal footprint excursion in Scenarios 1 and 2 and further evaluate their influence on the six sensitive targets in the Yangtze Estuary. Scenario 3 was utilised to analyse the negative effects of the footprint range on the spatio-temporal overlap of the Chinese sturgeon juveniles arriving in the estuarine reserve, set in the TGD-altered biological rhythm. Each scenario comprises four simulation sites from March to September, including three major urban sewage outlets, named Bailonggang (BLG), Zhuyuan (ZY), Shidongkou (SDK), and the upstream pollution source, represented by Xuliujing (XLJ). The results showed that the increased discharge in the dry season moved the post-TGD footprint further away from Chongming Island. Additionally, the outward side footprint was formed during the flood season, when the average discharge was lower than that during the pre-TGD period, being ‘pushed’ to the northwest by the monsoon and Taiwan warm current, resulting in a narrowing of the overall extent. The TGD positively impacted the XLJ and BLG simulation sites, given their shrinking footprint range and the decreasing trajectories of intruding sensitive targets in Scenario 2, in contrast to SDK and ZY.

Marking fin spine of juvenile sturgeon (acipenseriformes: acipenseridae) using oxytetracycline and the comparing of growth performance

ABSTRACT This study aimed to describe and validate the formation of the rings in the spine of the pectoral fin and to determine the coherence of the OTC mark with the rings of three species of Caspian Sea sturgeon, the Persian sturgeon (Acipenser persicus), the Starry sturgeon (Acipenser stellatus) and Ship sturgeon (Acipenser nudiventris). Validation was achieved by comparing the total radius of the fin spine of fish of known age after one and two years of growth with the measured radius of the first and second rings in the zone. There was no overlap between the measured radius for the first year and the increase for the second. The Ship sturgeon showed the largest width of the second ring followed by the Persian sturgeon and Stellate sturgeon. The results indicate that the highest growth parameter belongs to the juvenile Ship sturgeon. This research showed that chemically marking the fin spines of juvenile Acipenseridae leads to unbiased estimates and contributes to the knowledge of the population dynamics of these species. The study found that the combination of the dial ring of the pectoral fin spine with growth validated the age estimation in juvenile sturgeon Ship, Persian, and Starry sturgeon.

Влияние антиоксиданта дигидрокверцетина и иммуностимулятора арабиногалактана на рыбопродуктивность молоди осетровых

Влияние антиоксиданта дигидрокверцетина и иммуностимулятора арабиногалактана на рыбопродуктивность молоди осетровых

Dietary magnesium requirement on dietary minerals and physiological function of juvenile hybrid sturgeon (Acipenser schrenckii\u2640 \xd7 Acipenser baerii\u2642)

Sturgeons are an economically important freshwater aquacultural fish in China and elsewhere. Research was conducted to study the magnesium requirement of juvenile hybrid sturgeon (Acipenser schrenckii♀ × Acipenser baerii♂) based on mineral composition, proximate chemical analysis, antioxidant enzyme levels, and growth metrics. Different levels of magnesium supplements (43.2, 157.3, 326.5, 549.6, 743.9, 938.4, and 1118.2 mg kg−1) were fed to juvenile sturgeon for 8 weeks. Five hundred twenty-five juvenile hybrid sturgeons (an average initial body weight of 7.65 g) were randomly divided into 7 groups with 3 replicates each (25 fish per replicate, tanks of 100×50×50 cm, dissolved oxygen ≥ 5.0 mg L−1, 12 light:12 dark) and fed 4 times per day with the experimental diets containing 40.78% crude protein and 10.03% crude fat. The body tissues and blood of fish were then sampled and analyzed. Growth performance was not significantly different between treatments (P>0.05). The optimal dietary magnesium requirement for hybrid sturgeon was estimated to be 355.16, 573.6, or 584.6 mg kg−1 dietary magnesium based on whole-body Mg retention, the whole-body or vertebrae magnesium content versus dietary magnesium levels. The whole-body calcium to phosphorus ratio of the 43.2 and 326.5 mg kg−1 groups was significantly higher than that of the 938.4 mg kg−1 group (P< 0.05). A dietary magnesium concentration of 350–700 mg kg−1 improved the antioxidant capacity by decreasing the serum malondialdehyde and enhancing serum superoxide dismutase, glutathione peroxidase, and catalase activities.

Experimental passage of adult male Gulf sturgeon around Jim Woodruff Lock and Dam on the Apalachicola River, Florida

Dams can impede access to habitats that are required for the completion of life history phases of many migratory fish species, including anadromous sturgeons. Various forms of fish passage have been developed to permit migratory fishes to move above dams, but many dams still lack such structures. Translocation of ripe, mature fish above dams has been used as a first step to determine the efficacy of potential fish passage systems. The anadromous Gulf sturgeon, Acipenser oxyrinchus desotoi, inhabits the Gulf of Mexico and coastal rivers from Florida to Louisiana, and requires upriver spawning habitats to complete its life cycle. Historic overfishing and other anthropogenic threats, including dam construction, led to species declines and subsequent listing as threatened under the Endangered Species Act. In the Apalachicola River, FL, the 1957 completion of Jim Woodruff Lock and Dam (JWLD) created Lake Seminole and blocked Gulf Sturgeon from accessing 78% of historic riverine habitat—including potential spawning habitat—in the Apalachicola-Chattahoochee-Flint River Basin. The objective of this pilot study was to determine the efficacy of passage around JWLD through the trap-and-transport of 10 male Gulf sturgeon from the Apalachicola River to the reservoir above the dam. Through the use of acoustic telemetry, we were able to assess the ability of these fish to navigate Lake Seminole, access potentially suitable spawning habitat in the Flint and River, and complete their seasonal outmigration to the Gulf of Mexico. In this study, 2 translocated sturgeon moved 69 km upstream into potential spawning habitat in the Flint River, but 6 fish fell back through the lock/spill gates at JWLD within days of translocation. Four sturgeon appeared to remain trapped in the reservoir, and their long-term survival was deemed unlikely. Given our low sample size, and examination of male fish only, we cannot conclude that a trap-and-transport program would ultimately fail to restore spawning above JWLD, but our findings suggest that the risk of adult mortality is nontrivial. Alternatively, we suggest future studies examine the population level trade-offs associated with translocation of adults or consider alternatives such as a head-start program to rear and release juvenile sturgeon above JWLD to study viability of their passage in addition to effects on overall recruitment in the population.

Assessment of food intensity and growth rate young sevryuga (Acipenser stellatus Pallas, 1771) depending on from the terms of fishing of growing ponds

Artificial reproduction of sturgeon fish in the Volga-Caspian basin in modern conditions is the only real opportunity to replenish natural populations with juveniles, therefore, increasing its efficiency is the key to restoring the stocks of these relict fish species. Improving the technological processes of growing juvenile sturgeon fish, including the Caspian stellate sturgeon, the number of which has been rapidly decreasing in recent years, is one of the main tasks at present. We studied the conditions for growing stellate sturgeon larvae in the nursery ponds for artificial reproduction at different periods of their watering. It is known that the stocking of ponds with larvae that have switched to exogenous feeding occurs at the end of June or the beginning of July, this coincides with the time of maximum water heating in nursery ponds to extreme (26–28 °C) values and with a depletion of the food supply in them. Hydrobiological studies were carried out to assess the food supply in water bodies that were watered in the traditional (June 12–14) terms (control option) and earlier (May 28) 2 weeks earlier than usual (experimental option). In addition, the intensity of feeding and the growth rate of juvenile starred sturgeon in the indicated ponds was studied for 20–24 days. The results of the studies performed showed that the food supply in the experimental pond was higher, so the zooplankton was represented by four orders, the biomass on average ranged from 2,8 to 4,6 g/m³, and in the control variant, planktonic organisms were represented by three orders, total biomass from 0,3 to 2,5 g/m³. The same tendency can be traced for zoobenthos. The feeding intensity of stellate sturgeon fry reared in ponds of early watering had indicators in terms of the gastrointestinal tract filling index, fatness coefficient and growth rates higher than the juveniles kept in water bodies of traditional watering periods.

Changes in juvenile sturgeon erythrocytes across age classes reflects evolutionary development

Erythrocytes are important for gas transport and exchange in animals and play an important role in maintaining normal functions of the body. The purpose of this study was to observe the changes in erythrocyte morphology during the development of juvenile sturgeon (Acipenser baeri ♀×Acipenser schrenckii ♂ hybrid F1) and to describe the relationship between erythrocyte morphology and development. We compared the erythrocyte morphology of juvenile sturgeon in three developmental stages. The results showed that the blood index of the sturgeon in different age classes was significantly different. The erythrocyte volume in the blood became smaller and the shape of erythrocytes changed from circular to elliptical. With the increase in age, the number of self-dividing erythrocytes, and the types and numbers of organelles in the erythrocytes, decreased. The results demonstrated that the morphology and the internal structure of erythrocytes develop to be more beneficial for gas transport reflecting the needs for juvenile sturgeon maintenance and environmental changes.

Use of low-cost equipment for growing commercial sturgeon fish

The paper describes alternative low-cost equipment (in-ground pools) for keeping juvenile sturgeon fish. The results of the study of the hydrochemical regime of the compared fish breeding tanks, growth rates, and fish breeding and biological indicators of the juvenile fish contained in them are described. The object of the research was the juvenile bester (yearlings). As a result of growing fish in the compared containers, it was revealed that when using traditional type and frame pools there was no significant difference between fish breeding indicators. Compared fish breeding tanks provide the necessary hydrochemical regime for the cultivation of physiologically valuable juveniles of sturgeon fish with high growth rates. However, when keeping a yearling of the bester in the developed in-ground pool, there was a certain tendency to increase the intensity of fish growth. The concrete in-ground pool, in comparison with the compared fish breeding tanks, is not only the most reliable, but also close to the natural habitat of the fish (ponds) due to its high noise isolation and low vibration from fish life support system elements. It can be designed in any shape and size, placed anywhere. From a sanitary and environmental point of view, concrete pools are the most preferred option.

Physiological responses of Siberian sturgeon (Acipenser baerii) juveniles fed on full-fat insect-based diet in an aquaponic system

Over the last years, the potential use of Black Soldier Fly meal (BSF) as a new and sustainable aquafeed ingredient has been largely explored in several fish species. However, only fragmentary information is available about the use of BSF meal-based diets in sturgeon nutrition. In consideration of a circular economy concept and a more sustainable aquaculture development, the present research represents the first comprehensive multidisciplinary study on the physiological effects of a BSF diet during sturgeon culture in an aquaponic system. Siberian sturgeon (Acipenser baerii) juveniles were fed over a 60-days feeding trial on a control diet (Hi0) and a diet containing 50% of full-fat BSF meal respect to fish meal (Hi50). Physiological responses of fish were investigated using several analytical approaches, such as gas chromatography-mass spectrometry, histology, Fourier Transformed Infrared Spectroscopy (FTIR), microbiome sequencing and Real-time PCR. While aquaponic systems performed optimally during the trial, Hi50 group fish showed lower diet acceptance that resulted in growth and survival reduction, a decrease in hepatic lipids and glycogen content (FTIR), a higher hepatic hsp70.1 gene expression and a worsening in gut histological morphometric parameters. The low feed acceptance showed by Hi50 group sturgeon highlighted the necessity to improve the palatability of BSF-based diet designed for sturgeon culture.

Oxidative Stress and Antioxidant Defense Mechanisms in Response to Starvation and Refeeding in the Intestine of Stellate Sturgeon (Acipenser stellatus) Juveniles from Aquaculture.

Simple SummaryThe stellate sturgeon (Acipenser stellatus) is a critically endangered species due to multiple causes including human impact, with its valuable roe being used for caviar production. As a consequence, it is intensively raised in aquaculture for both conservation and economical purposes. Food deprivation can occur in both natural and aquaculture environments due to specific conditions that impose food restrictions (such us extreme temperatures, deterioration of water quality, pathological manifestations). The purpose of this study was to investigate the physiological adaptability of stellate sturgeon under two starvation/refeeding regimes. Therefore, the study had two objectives: to assess the effects of an alternative feeding regime on oxidative stress biomarkers and to assess the antioxidant defense mechanisms in juveniles raised in aquaculture. The results showed that the starvation/refeeding regimes induced lipid peroxidation and an enhancement of antioxidant enzymes activities in the intestine of stellate sturgeon juveniles. To conclude, Acipenser stellatus proved to possess a potential to adapt to a starvation/refeeding regime, the most suitable being a 7-day starvation period followed by 21 days of refeeding. This regime could be useful to optimize the feeding practice in aquaculture production in order to increase the profitability of fish farming without affecting the stellate sturgeon juveniles. Acipenser stellatus is a critically endangered species due to the anthropic influence. It has been intensively captured for decades because of its high economic value, its roe being used in the caviar industry. Therefore, Acipenser stellatus is intensively raised in fish farms for both conservation and economical purposes. Aquaculture aims to optimize the feeding regime of juveniles in order to improve its profitability. The purpose of this study was to investigate if Acipenser stellatus can adapt to a starvation/refeeding regime by assessing the effects of this regime on oxidative stress biomarkers and antioxidant defense mechanisms in juveniles raised under aquaculture conditions. The juveniles were subjected to two regimes: a 7-day starvation period followed by 21 days of refeeding, respectively a 14-day starvation period followed by 21 days of refeeding. The results showed that both starvation/refeeding regimes induced an enhancement of antioxidant enzymes activities in the intestine of the juveniles. The oxidative damage was counteracted at the protein level. However, lipid peroxidation was significantly induced in the intestine of the juveniles subjected to 14/21-day starvation/refeeding regime. The 7/21-day starvation/refeeding regime proved to be more suitable for Acipenser stellatus and therefore, it could be useful to optimize the feeding practice in aquaculture production.

Study of the osmotic regulation processing in the juvenile Persian sturgeon, Acipenser persicus. Borodin, 1897 in transfer directly to the Caspian seawater

The aim of this study was to transfer directly juvenile Acipenser persicus from freshwater to the Caspian Seawater (CSW). The fish in different age and size (weight (W) &amp; length (L)) groups (I: 35days, W: 2.75±0.15g &amp; L: 7.93±0.47cm; II: 50days, W: 3.15±0.12g &amp; L: 8.31±0.28cm; III: 65days, W: 4.33±0.12g &amp; L: 9.39±0.29cm; n=90 for each group) and in two different saline water (FW: &lt;0.5‰ and CSW: 12.5‰) were investigated. The fish were transferred directly from FW to CSW. After 168 hours, blood samples were taken from the fish. The results showed that the survival in all groups in CSW was from 56% up to 76% and increased with increasing age and weight of fish. Some hematological parameters and levels of cortisol, osmolarity and ion concentration (Na+, K+, Ca+2 and Mg+2) in the plasma were determined. The functional levels of the mechanism of osmotic and ionic homeostasis were similar in all groups (P&gt;0.05) but differed in experimental media (P&lt;0.05). Significant differences were observed between the levels of plasma ion concentrations in different media (P&lt;0.05). Plasma Na+, K+ and Ca+2 concentrations were higher than those of FW media, but lower than in Brackish water media (P&lt;0.05). Plasma Mg+2 concentrations were lower than those of FW and Brackish water media (P&lt;0.05). The Hct, Hb, MCV, MCH and plasma osmolarity decreased and MCHC and plasma cortisol levels increased with increasing salinity (P&lt;0.05). But the number of WBC and RBC did not change (P&lt;0.05) and reached a stable state. Therefore, it is possible to release juvenile sturgeon directly from FW to CSW with increasing weight and age.

Testing of experimental feed for young Australian red-clawed crayfish that meets its nutritional needs

One of the relatively promising types of world aquaculture is the Australian redclawed crayfish, which is one of the relatively promising objects in warm-water aquaculture. Compared to other farmed crustaceans (shrimps, crabs), Australian crayfish is characterized by a high growth rate and unpretentiousness to the conditions of aging. In the process of cultivation of red-clawed crayfish, industrial granulated feeds developed for other types of hydrobionts (shrimps, fish) are currently used. In the presence of biotechnological standards for growing juveniles and commercial products of red-clawed crayfish, the question remains open about the lack of production of balanced specialized feeds for them. The purpose of this work was to test an experimental feed developed according to its own recipe for young Australian red-clawed crayfish. The main stages of the technology of preparation of the above feed are described. The experimental feed was compared with production dry feed according to the main parameters (qualitative composition, nutritional value, consumer characteristics). Taking into account the nutritional needs of crayfish in the main nutrients (protein, fat, fiber), three types of food were selected: for loricarium catfish, for juvenile sturgeon and experimental. In accordance with them, three variants of the experiment were laid down, where the conditions of maintenance (planting density, temperature and light modes, feeding frequency) were identical, except for differences in the type of feed. During the experiment, the main differences in the size and weight parameters of groups of juvenile Australian crayfish cultured using these feeds were revealed. The necessary conditions for keeping crustaceans in the laboratory and the scheme of their control are described.

Influence of growth on the biological and commercial productivity of Caspian great sturgeon Huso huso

Fisheries management has expanded from a traditional focus to a more holistic model based on a model describing the change in the number of generations of fish under the influence of age-dependent natural mortality and harvesting. We calculated the abundance, biomass, production, natural, total loss and catches from the conditional population of great sturgeon resulting from the replenishment of 1.0 million instances of fingerlings with different rates of linear and weight growth in the period 1931–1975. It was found that the size of fingerlings has the greatest influence on the abundance and biomass of conditional great sturgeon populations formed from juveniles. We found an increase in the length of annuals of 19.3%, with the biomass of the conditional population, its production and catch size increasing by 2.9 times. Thus, cultivation of sturgeon in sturgeon hatcheries (SH) and the release of large sized great sturgeon juveniles into the sea will significantly increase the efficiency of work of the artificial reproduction of stocks.