Juvenile Beluga Research Articles

The Effects of Different Levels of Potassium Diformate and Calcium Diformate on Growth, Digestion Enzyme Activity, Antioxidant Capacity, Intestinal Flora, Stress Markers, and Some Serum Biochemical Analytes in Juvenile Beluga Huso huso

The Effects of Different Levels of Potassium Diformate and Calcium Diformate on Growth, Digestion Enzyme Activity, Antioxidant Capacity, Intestinal Flora, Stress Markers, and Some Serum Biochemical Analytes in Juvenile Beluga Huso huso

Features of cultivation of hydrid forms of sturgeon fish in quarriers of the Rostov region

The paper presents the results of growing juvenile sturgeon species and their hybrid forms in a mine pit lake in the Rostov region. In the Rostov region, there are many mine pit lake that can be successfully used to organize economic activities for the cultivation of valuable aquaculture objects, such as sturgeon fish. It has been established that the hydrochemical regime of the lake from May to September is favorable for the cultivation of juvenile sturgeon fish species and their hybrid forms. Studies have shown that the highest growth rate for 30 days of growing in pools was shown by beluga juveniles, its absolute increase was 1200 mg with a survival rate of 75%. Lenk and Bester had an increase of 565 mg and 710 mg, respectively. The most highly sensitive was the transition of juveniles to active nutrition, when the yolk sac in the larvae resolved by 2/3. The fastest transition and the least waste was observed in the larvae of bester and lenka. Upon reaching the age of 30 days, the juveniles were transplanted into cages, where good growth of beluga juveniles and hybrids was noted. On June 15 (40 days), the juveniles switched completely to dry food. At the same time, the average weight of the beluga was 3.5 g. It should be noted that with the complete transfer of beluga juveniles to dry food, the waste was from 3 to 5%. The young of Lenka and bester adapted better to dry food, the waste did not exceed 2%. The largest growth was in juveniles of all sturgeon species in August and early September.

Optimum feeding of schemes of beluga (Huso huso L.) at the early stages of ontogenesis in the conditions of industrial aquaculture

Aquaculture is the fastest growing food production industry. The priority direction of freshwater aquaculture is sturgeon breeding. One of the significant stages of the technological cycle of industrial rearing of sturgeons is the maintenance of juveniles during the transition to exogenous nutrition. In industrial fish farming, based on keeping fish under fully controlled aquatic conditions, the use of natural feed is becoming increasingly limited.Despite the use of artificial compound feed, balanced in terms of the main nutrients, only live food serves as a supplier of all biologically active substances, contains proteins that include all essential amino acids, unsaturated fatty acids, vitamins, enzymes and other vital substances, and also helps to increase the activity of all digestive enzymes, causing the overall activity of the body. The article describes the experience of growing beluga (Huso huso L.) in the pools installed in the RAS “Educational and Scientific Complex of Pilot Aquaculture Production” LLP (Uralsk, Kazakhstan).The results of an experiment to determine the optimal feeding schemes for the sturgeon in the early stages of ontogenesis are presented. It has been established that feeding only аrtemia nauplii and decapsulated аrtemia cysts leads to a mass departure of larvae, and analysis of their stomach contents showed that there was no food in them. To facilitate the transition from feeding live food to artificial food, it is optimal to combine different types of live food with pelleted food. The addition of brine shrimp and bloodworms to the diet of dry granulated food contributes to the greatest increase in the growth rate and survival of larvae and juvenile beluga.

Efficacy of dietary thiamine supplementation on growth performance, digestive enzymes, immunological responses, and antioxidant capacity of juvenile beluga (Huso huso)

The aim of the current study was to investigate the beneficial effects of dietary thiamine supplementation on physiological, immunological and antioxidant responses in juvenile beluga, Huso huso. The juvenile fish (∼ 3 g) were fed four times a day with diets containing 0 (control), 5 (5 T), 10 (10 T), and 20 (20 T) mg kg−1 thiamine for 12 weeks. Significant increases were observed in growth performance indicators of the fish fed different levels of thiamine, compared to the control group and the best performance was observed in 10 T treatment. The carcass protein content significantly increased in the thiamine-treated fish and the highest protein content was observed in the 10 T treatment. Digestive enzymes’ activities (pepsin, trypsin, lipase, and amylase) significantly increased in the fish fed the thiamine-supplemented diets. The serum alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase activities significantly decreased in the 10 T and 20 T treatments, compared to the control group. Dietary thiamine supplementation significantly increased the serum lysozyme, alternative complement activities, and IgM level, compared to the control diet and the highest lysozyme activity and IgM level were observed in the 10 T and 20 T treatments. The hepatic superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione-s-transferase, transketolase activities of 10 T and 20 T treatments were significantly higher than those of the control treatment. The hepatic catalase activities in the thiamine-treated fish were significantly higher than that of the control fish. Contrastingly, the hepatic malondialdehyde contents of the 5 T, 10 T, and 20 T treatments were significantly lower than the control treatment. Although all the dietary thiamine levels (5–20 mg kg−1) showed beneficial effects on different tested parameters, 10 mg kg−1 was the most beneficial level and is recommended for dietary inclusion to improve the growth and health of juvenile beluga.

Growing juvenile beluga and its hybrids with sterlet in environmentally friendly conditions

Currently, the general trend of the global fishing industry is to increase the production of fish food products not only due to the development of aquaculture, but also the biological characteristics of the body of sturgeon. The aim of the study was the theoretical justification and practical implementation of the assessment of the growth and development of beluga juveniles and their hybrids with sterlet aged 0+ to 2+ (three-year-olds) in industrial of the Krasnodar Territory. The determined: fish mass, live weight gain, linear growth. By the end of the control cultivation, the weight of fish in the control and experimental groups was 1728.3 and 2236.4 g, respectively. In the experimental group, the absolute increase in live weight of fish was 2198.2 g, while in the control group it was 1692.2 g. The difference in average daily gains was 0.71 g in favour of hybrids. The body length of the fish in the control and experimental groups was 32.7 and 37.3 cm. The positive effect of heterosis had a positive effect on the first- generation crossbreeds obtained from beluga and sterlet.

Effects of caffeic acid on the growth performance, growth genes, digestive enzyme activity, and serum immune parameters of beluga (Huso huso)

Caffeic acid is a phenolic metabolite known for its beneficial pharmaceutical effects and is suggested as a functional additive for aquaculture. In this study, the effects of caffeic acid on the growth performance, growth genes, digestive enzyme activity, and serum immune parameters of beluga (Huso huso) were investigated. For this purpose, 120 beluga juveniles (367.75 ± 21.32 g) were divided into 12 tanks and fed with caffeic acid at rates of 0 (T0, control), 1 (T1), 5 (T2), and 10 (T3) g/kg for 56 days. The final weight and weight gain of beluga were significantly higher in fish fed 5 (T2) and 10 (T3) g caffeic acid/kg than in the control group and 1 (T1) g caffeic acid/kg. The specific growth rate was significantly higher in beluga fed 10 g caffeic acid/kg than 0 and 1 g/kg. Compared with the control group, the amylase, lipase, and pepsin activities were significantly higher in T2 and T3. The relative expression of growth hormone and insulin-like growth factor significantly increased in T3 compared with the control group. The expression of lipoprotein lipase and nuclear factor interleukin 3 of beluga fed 5 and 10 g caffeic acid/kg was higher than the control group. The lysozyme activity, total immunoglobulin, and total protein in the serum of beluga significantly increased in fish fed with caffeic acid at different rates compared with the control group. Based on the finding, the results suggested that the inclusion of caffeic acid (5-10 g/kg) in the diets of beluga is recommended to enhance the growth performance, some digestive enzyme activity, and serum immune parameters.

Combined effects of Pediococcus acidi lactici and natuzyme on growth performance, hematology and immunity indices in juvenile beluga (Huso huso)

The present study was performed to compare the combined and individual effects of Pediococcus acidi lactici (PB) and natuzyme (a cocktail of protease, lipase as well as non-starch polysaccharidases) on the immune response and growth performance parameters of the juvenile beluga (Huso huso). To prepare the treatment diets, the basal diet was supplemented with either the exogenous natuzyme (at 0, 0.25 and 0.5 g kg−1), PB (at 0% and 0.1%) or both of them. The six treatments were assigned to triplicate groups and the feeding trial lasted for two months. The results showed that PB treatment constrained the positive effect of EN (especially at the higher dose) on the FCR and final weight. However, IGF and GH expression not only increased following either PB or EN inclusion, but also, their simultaneous addition promoted their individual effects. Together, higher level of GH and IGF mRNA levels in this study was not associated with a significant growth enhancement, this can be due to the fact that more time should be considered to display their effects. In the light of these results, we recommend that the combined use of probiotics and exogenous enzymes especially at the higher dose can be inhibitory.

Correction to: The effect of a phytogenic feed additive (Digestrom P.E.P) on growth performance, proximate composition, hematological and immunological indices of juvenile beluga sturgeon Huso huso

Correction to: The effect of a phytogenic feed additive (Digestrom P.E.P) on growth performance, proximate composition, hematological and immunological indices of juvenile beluga sturgeon Huso huso

Исследование морфофизиологических показателей ремонтной группы белуги, культивируемой в искусственных условиях среды

The sturgeon fish populations in the main reservoirs of the country are in a crisis. Efficiency of natural reproduction of these fish species is extremely low and currently the replenishment of populations is mainly achieved due to artificial breeding. Beluga, one of the sturgeon fish species living in the Caspian basin, is classified as endangered, being in particularly difficult circumstances. Over the past hundred years its abundance has undergone fluctuations due to the natural and anthropogenic factors. Due to the sharp reduction in the volume of artificial reproduction by fish hatcheries of the Lower Volga and the threat of species extinction there was carried out the research of the quality of beluga juveniles of different ages cultivated in artificial environment. Morphophysiological parameters of beluga juveniles of different ages cultivated in cages and ponds are investigated. The concentration of hemoglobin in the studied groups ranged from 56.3 to 70.3 mg/l (the data were within the reference values), which indicates an increased level of metabolism. Low values of the erythrocyte sedimentation rate in different growing conditions (from 4.5 – 6.4 mm/h) were noted, which indicates the absence of inflammatory or pathological processes in the body of hydrobionts. Concentration of total whey protein in the studied groups was also within the physiological norm. As a result of the studies, it can be concluded that such parameters as total protein, cholesterol, glucose and β-lipoproteins are not affected by age, but mainly depend on fish nutrition. The obtained analysis of sturgeon morphophysiological indicators (grown in different conditions) complements the missing information for monitoring the physiological state of these valuable representatives of aquaculture, adjusting biological standards of cultivation and the technological processes in the ponds and industrial complexes.

The effect of a phytogenic feed additive (Digestrom P.E.P) on growth performance, proximate composition, hematological and immunological indices of juvenile beluga sturgeon Huso huso

The effect of a phytogenic feed additive (Digestrom P.E.P) on growth performance, proximate composition, hematological and immunological indices of juvenile beluga sturgeon Huso huso

Can dietary ethanolic extract of propolis alter growth performance, digestive enzyme activity, antioxidant, and immune indices in juvenile beluga sturgeon (Huso huso)?

The present study investigated the effects of dietary ethanolic extract of propolis on growth performance, digestive enzyme activity, liver antioxidant capacity, and skin mucus immunity in beluga sturgeon. For this purpose, a total of 120 juvenile fish (595.55 ± 31.61 g) were distributed in 12 tanks and fed with ethanolic extract of propolis at 0, 1, 2, and 3% for 60 days. The current study results showed that growth indices and the survival rate did not change in the juvenile fish fed with this extract compared to the control group. However, the protease activity, pepsin, and chymotrypsin were significantly higher in beluga sturgeon fed with the treated diet than the control fish (P < 0.05). The results also showed a higher white blood cell count in fish provided with 2 and 3% extract than in the control group (P < 0.05). The level of the alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase activities in the fish liver remained unaffected in all groups (P˃0.05). Meanwhile, the activities of antioxidant-related enzymes were significantly higher (P < 0.05) in the liver of beluga sturgeon fed with dietary ethanolic extract of propolis, especially at 3%, than the control fish. In 2 and 3% treated groups, the skin mucus of beluga sturgeon showed an enhanced lysozyme activity and total immunoglobulin level (P < 0.05) compared to the control group. In parallel, the in vitro assay revealed an elevated serum antibacterial activity against Aeromonas hydrophila in the fish fed with 2 and 3% extract compared with the control group (P < 0.05). It can be concluded that the supplementation of ethanolic extract of propolis, especially at 3%, could improve some digestive enzyme activities, liver antioxidant capacity, and skin mucus immunity of juvenile beluga sturgeon.

Effects of dietary polyphenols on mucosal and humoral immune responses, antioxidant defense and growth gene expression in beluga sturgeon (Huso huso)

Tannins are a class of polyphenols, well known for their potent natural antioxidant properties, which have a beneficial effect on the digestive tract and contribute to improving the welfare of terrestrial farmed animals. This study reports the effect of tannins on haematological and non-specific immune parameters, serum enzyme activity and expression of growth genes of juvenile beluga sturgeon (Huso huso). Tannins were extracted from chestnut wood by SILVATEAM and provided in form of powder, under the commercial name of Silvafeed®ATX. Triplicate groups of 35 Beluga juveniles each (39.20 ± 0.63 g) were placed in 9 oval tanks (350 L) and fed with the basal control diet (0% tannins) and the tannin supplemented basal diet (at 0.05 or 0.1%). The trial lasted 6 weeks. The dietary supplementation of 0.1% tannins significantly improved weight parameters and food conversion ratio (FCR) with respect to the control group (P < .05). Dietary tannins had no significant effect on body composition and haematological parameters. Skin and mucus lysozyme and oxidative stress related enzymes activity (CAT, PPO and SOD) significantly increased in the groups fed tannins enriched diets (P < .05). The enzymatic activity of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase did not change between control and tannin fed groups. Finally, the expression of two growths related genes: gh and igf-i was upregulated in the tannin fed groups. Such outcomes indicate that tannins improve growth performance and the general health status of juvenile beluga sturgeon. Thus, our results suggest that tannins administered to juvenile beluga sturgeon may act as growth promoters.

Effect of diets with different levels of soybean meal and Kemin multi-enzyme on growth performance, body composition, and gut lactic acid bacteria of juvenile Beluga (Huso huso)

Effect of diets with different levels of soybean meal and Kemin multi-enzyme on growth performance, body composition, and gut lactic acid bacteria of juvenile Beluga (Huso huso)

Fluctuation of biochemical, immunological, and antioxidant biomarkers in the blood of beluga (Huso huso) under effect of dietary ZnO and chitosan–ZnO NPs

The objective of the present study was to investigate the effects of dietary supplementation with zinc oxide (ZnO) and chitosan-zinc nanoparticles (chitosan-ZnO NPs) on biochemical, immunological, and antioxidant biomarkers in blood of juvenile belugas (Huso huso). The beluga juveniles with initial weight of 287 ± 46 g were fed with eight experimental diets containing 0 g kg-1 ZnO (the control diet); 10, 20, and 40 mg kg-1 ZnO; and 10, 20, and 40 mg kg-1 chitosan-ZnO NPs and 36 mg kg-1 chitosan. After 28 days of culture, the fish were fed with ZnO and chitosan-ZnO NP-supplemented diets showed a more significant increase in total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPX), and glutathione S-transferase (GST) activity (p < 0.05) compared to the control group. There were no significant differences (p > 0.05) in malondialdehyde (MDA) and glucose level in all treatment groups. The results showed that with increasing levels of ZnO and chitosan-ZnO NPs, alternative complement activity (ACH50), and total immunoglobulin, total protein, albumin, and lysozyme had a significant increase in fish fed with ZnO and chitosan-ZnO NP-supplemented diets compared to the control group (p < 0.05). ALP, ALT, and AST enzyme activities showed significant difference between control and treatment groups (p > 0.05), while the levels of LDH enzyme activity, urea, and creatinine decreased by increasing both ZnO and chitosan-ZnO NP levels. These results demonstrated that dietary chitosan-ZnO NPs could improve the health status, immune function, and antioxidant capacity of the cultured beluga juvenile.

Ventilation frequency in juvenile beluga sturgeon Huso huso L. exposed to clay turbidity

A 2-factorial experiment was conducted to investigate the effect of clay turbidity on ventilation frequency (VF) in juvenile beluga sturgeon Huso huso. Ninety fish (initial mean weight 27.2 ± 0.1 g) were exposed to six levels of turbidity (0.0, 2.5, 5.0, 10.0, 20.0 and 40.0 g clay/l) for three min. Then, the fish were gently transferred to a recovery tank and monitored to record the VF for 3 min. Results indicated that clay turbidity significantly affected the VF of the fish. The highest VF was observed in the first minute after the exposure. VF increased with increasing clay turbidity levels. In addition, the obtained results showed that VF of the beluga decreased through the time. Based on the result, it can be concluded that the beluga has the ability to adapt to clay turbidity in a short time; although they had an acute stress at first.

Modifying the physiological responses to handling stress in beluga sturgeon Huso huso (Linnaeus, 1758); Interactive effects of feeding time and dietary fat

The present study investigated the interaction of feeding times with two dietary fat levels on physiological responses to handling stress in juvenile Beluga sturgeon. Fish were fed with two different diets (high energy; HE: 24% fat and low energy; LE: 12% fat) for 8 weeks at two feeding times; 09:00 and 16:00 (during the day) or 21:00 and 04:00 (during the night). At the end of the trial, blood samples were taken and the resting fish were held in a net out of water for 90 s as the handling stressor. Three hours after application of stress, post-stress blood was taken. Cortisol, glucose, and lactate concentrations were considered as stress indicators. The mean values of cortisol and lactate levels did not reveal a significant difference between pre- and 3-hr post-stress samples, but the average concentration of glucose showed a significant difference. Cortisol, lactate and glucose concentrations were not influenced by the difference in the diets. Moreover, the cortisol and lactate concentrations were not affected by the different feeding times, while glucose levels were significantly affected by the feeding times with the lowest level in fish fed during the day. With respect to stress indicators, the results revealed that feeding times affected pre- and post-stress secondary response to handling stress, but the rate and magnitude of metabolites (cortisol, glucose and lactate) were not affected by dietary fat levels. Therefore, it is necessary to examine the best feeding times with the interaction of feed ingredients in sturgeon farming.

Anadromous Sturgeons (Acipenseridae, Actinopterygii) of the Don River Upstream from the Tsimlyansk Hydroengineering Complex

Abstract—Data based on the results of published, unpublished, and questionable materials concerning the occurrence of anadromous sturgeons after damming of the Don River downstream and upstream of the Tsimlyansk hydroengineering complex are presented. Two peaks of approaches of spawners to the dam in the 1950s and 1980s were recorded. The first peak was related to the wild population that existed in these years; the second peak was a result of mass artificial propagation. At the first stage, the Russian sturgeon (Acipenser gueldenstaedtii Brandt et Ratzeburg, 1833) and the beluga sturgeon (Huso huso (Linnaeus, 1758)) prevailed downstream from the dam; at the second stage, only the Russian sturgeon was recorded. Since 1955, only 21 individuals of anadromous sturgeons have made it through the dam by a fish ladder. During the years 1952–1961, 1145 individuals were transported into the reservoir, including 218 ind. of beluga. Some individuals of beluga were transported later as well. There are data indicating the presence of juvenile beluga individuals that originated from natural spawning in the reservoir before the 1970s. The last known spawners of Russian sturgeon and stellate sturgeon (Acipenser stellatus Pallas, 1771) in the reservoir were recorded in the 1980s or 1990s. Solitary beluga individuals may occur nowadays. It is suggested that the youngest of the noted individuals belong to the generations of the early 1990s. It is concluded that the extremely innumerous landlocked form of the Azov beluga may still exist in the reservoir.

A comparative study of feeding methods: Effect on the growth, behaviour and biochemical performance of juvenile Beluga sturgeon ( Huso huso Linnaeus, 1758)

This study compared the influence of feeding methods on growth parameters of young-of-year Beluga sturgeon Huso huso in a 6-week trial. Fish with an average weight 150.3 ± 0.8 g (±SE) were stocked into nine circular concrete tanks (30 fish per tank) in an open circular system with water temperature of 18.9°C. All fish were fed by three different feeding methods: (a) hand-fed (HF), (b) continuously available (automated feeder; AF), (c) half of daily feed provided by hand, and another half by automated feeder (combined feeding). For the hand-feeding method, fish were fed at 09:00, 14:00, 19:00, and 24:00. The entire automatic feeding groups were fed with the same amount of feed. The mean final body weight was the highest in fish fed by AF compared to fish fed by HF. Body weight increase, condition factor, specific growth rate, and feed conversion ratio did not differ among the feeding groups. Fish fed by AF revealed higher swimming activity than the HF group. No significant changes were found in hematocrit, glucose and total protein concentrations among treatments. The results showed less dependence of growth and physiology of Beluga sturgeon on feeding method, but automated-feeding was shown to be suitable for sturgeon rearing because of further low labour costs in rearing systems.

Inclusion of Pediococcus acidilactici as probiotic candidate in diets for beluga (Huso huso) modifies biochemical parameters and improves immune functions.

Administration of probiotic candidates in fish has generally been shown as a useful strategy to improve growth performance, survival, digestive enzyme activity, and gut microbiota. Unfortunately, the sero-immunological responses of different fish to different probiotic candidates are poorly understood. The present study assessed the effect of Pediococcus acidilactici as a probiotic on the biochemical and immunological parameters of beluga. Fish (248.32 ± 10.21g) were fed a control diet (without P. acidilactici( and three different doses of P. acidilactici-supplemented diets (107, 108, and 109CFUg-1 diets) for 8weeks. On week 8, blood and serum were sampled. Dose-dependent increase of immunological parameters (respiratory burst activity, lysozyme content, serum antibacterial activity, and total immunoglobulin) and biochemical parameters (total protein and albumin levels) was observed. However, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly increased in the juvenile beluga fed by 109CFUg-1 P. acidilactici-supplemented diet compared to the other groups. Based on the results of this evaluation, it is reasonable to conclude that the inclusion of P. acidilactici as probiotic in diets for juvenile beluga improves the sero-immunological parameters of the fish and should be considered by farmers as a strategy to improve fish health.

МОРФОФИЗИОЛОГИЧЕСКАЯ ХАРАКТЕРИСТИКА МОЛОДИ ОСЕТРОВЫХ РЫБ, ВЫРАЩЕННОЙ НА РЫБОВОДНЫХ ЗАВОДАХ АСТРАХАНСКОЙ ОБЛАСТИ

The article focuses on the study of changeability of morphological and physiological characteristics of 850 specimens of beluga ( Huso huso ) and sturgeon ( Acipenser gueldenstaedtii ) juveniles obtained at the Ikryaninskiy and Bertyulskiy sturgeon hatcheries in the Astrakhan region. There was determined weight of the body, heart, liver and spleen, as well as the relative mass of these organs - cardiosomatic, hepatosomatic indices and index of a spleen. Sturgeon juveniles were studied within 47-127 days, beluga juveniles within 40-116 days. Certain tendency was noted: cardiosomatic index decreased with aging in both sturgeon and beluga, i.e. the relative weight of the heart in ontogenesis changes inversely to the body weight, which corresponds to literature data. Comparison of the dynamics of the liver relative weight in sturgeon and beluga juveniles showed that it coincides at two segments: maximum raise to 50-60ths day from the birth and a gradual decrease in older juveniles. The value of spleen index in juveniles of both types rose with aging. It was found in the course of the study that the size of internal organs could change, getting smaller under unfavorable factors, in particular, when juveniles suffer from the lack of feeds. In such circumstances the dynamics of developing main internal organs drastically slows down, which reflects on physiological adequacy (quality) of juveniles. Thus, morphological and physiological indicators characterizing the degree of the vitals development can be used not only for characterizing species differences of the investigated group of fish at all stages of ontogenesis, but as important factor for assessing conditions of Russian sturgeons juvenile breeding and the degree of morphological and physiological maturity of the juveniles before releasing into the natural water body.