Siberian Sturgeon Research Articles

Confirmation of induced hybrid from female ship sturgeon (Acipenser nudiventrisLovetsky, 1828) and male Siberian sturgeon (Acipenser baerii, Brandt, 1869) using microsatellite markers

Journal of Applied IchthyologyVolume 31, Issue 6 p. 1002-1005 Short Communication Confirmation of induced hybrid from female ship sturgeon (Acipenser nudiventris Lovetsky, 1828) and male Siberian sturgeon (Acipenser baerii, Brandt, 1869) using microsatellite markers M. Hassanzadeh Saber, Corresponding Author M. Hassanzadeh Saber Genetics and Biotechnology Department, International Sturgeon Research Institute, Agricultural Research Education and Extension Organization (AREEO), Rasht, Iran Author's address: Mohammad Hassanzadeh Saber, Genetics & Biotechnology Department, International Sturgeon Research Institute, P. O. Box: 41635-3464, Rasht, Iran. E-mail: saber.merag@gmail.comSearch for more papers by this authorS. Baradaran Noveiri, S. Baradaran Noveiri Genetics and Biotechnology Department, International Sturgeon Research Institute, Agricultural Research Education and Extension Organization (AREEO), Rasht, IranSearch for more papers by this authorM. Pourkazemi, M. Pourkazemi Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), Tehran, IranSearch for more papers by this authorM. R. Nowruzfashkhami, M. R. Nowruzfashkhami Genetics and Biotechnology Department, International Sturgeon Research Institute, Agricultural Research Education and Extension Organization (AREEO), Rasht, IranSearch for more papers by this authorM. Yarmohammadi, M. Yarmohammadi Genetics and Biotechnology Department, International Sturgeon Research Institute, Agricultural Research Education and Extension Organization (AREEO), Rasht, IranSearch for more papers by this authorM. A. Salari Aliabadi, M. A. Salari Aliabadi Khorramshahr University of Marine Sciences and Technology, Khorramshahr, IranSearch for more papers by this authorH. Zolgharnein, H. Zolgharnein Khorramshahr University of Marine Sciences and Technology, Khorramshahr, IranSearch for more papers by this authorM. T. Ronagh, M. T. Ronagh Khorramshahr University of Marine Sciences and Technology, Khorramshahr, IranSearch for more papers by this author M. Hassanzadeh Saber, Corresponding Author M. Hassanzadeh Saber Genetics and Biotechnology Department, International Sturgeon Research Institute, Agricultural Research Education and Extension Organization (AREEO), Rasht, Iran Author's address: Mohammad Hassanzadeh Saber, Genetics & Biotechnology Department, International Sturgeon Research Institute, P. O. Box: 41635-3464, Rasht, Iran. E-mail: saber.merag@gmail.comSearch for more papers by this authorS. Baradaran Noveiri, S. Baradaran Noveiri Genetics and Biotechnology Department, International Sturgeon Research Institute, Agricultural Research Education and Extension Organization (AREEO), Rasht, IranSearch for more papers by this authorM. Pourkazemi, M. Pourkazemi Iranian Fisheries Science Research Institute, Agricultural Research Education and Extension Organization (AREEO), Tehran, IranSearch for more papers by this authorM. R. Nowruzfashkhami, M. R. Nowruzfashkhami Genetics and Biotechnology Department, International Sturgeon Research Institute, Agricultural Research Education and Extension Organization (AREEO), Rasht, IranSearch for more papers by this authorM. Yarmohammadi, M. Yarmohammadi Genetics and Biotechnology Department, International Sturgeon Research Institute, Agricultural Research Education and Extension Organization (AREEO), Rasht, IranSearch for more papers by this authorM. A. Salari Aliabadi, M. A. Salari Aliabadi Khorramshahr University of Marine Sciences and Technology, Khorramshahr, IranSearch for more papers by this authorH. Zolgharnein, H. Zolgharnein Khorramshahr University of Marine Sciences and Technology, Khorramshahr, IranSearch for more papers by this authorM. T. Ronagh, M. T. Ronagh Khorramshahr University of Marine Sciences and Technology, Khorramshahr, IranSearch for more papers by this author First published: 03 October 2015 https://doi.org/10.1111/jai.12878Citations: 3Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume31, Issue6December 2015Pages 1002-1005 RelatedInformation

Analysis of the leukogram of sturgeons (Acipenser baerii (Brandt) and A. gueldenstaedtii (Brandt)) grown in artificial reservoirs

The peripheral blood leukogram of immature sturgeons, both males and females, has been analyzed: Siberian (Acipenser baerii Brandt) and Russian (A. gueldenstaedtii Brandt) sturgeons grown in artificial pools. It has been shown that lymphocytes are the dominant form of leukocytes (>80%) in both species. Monocytes can be found in the A. baerii. In our opinion, this demonstrates the impact of adverse environmental factors. In A. gueldenstaedtii, on the contrary, basophils have been found, which are often observed under the deterioration of the conditions in the pools and indicate an improvement in body defenses.

Histopathological effects of silver and copper nanoparticles on the epidermis, gills, and liver of Siberian sturgeon.

The influence of nanoparticles (NPs) on aquatic environments is still poorly documented. The aim of the study was to determine the effects of silver (AgNPs) and copper (CuNPs) nanoparticles on larval Siberian sturgeon (Acipenser baerii) after 21 days of exposure. Acute toxicity of AgNPs on Siberian sturgeon was investigated in a 96-h static renewal study and compared with the toxicity of CuNPs. The AgNPs and CuNPs 96 h mean lethal concentrations (96 h LC50) were 15.03 ± 2.91 and 1.41 ± 0.24 mg L−1, respectively. Toxicity tests were done in triplicates for each concentration of AgNPs 0.1, 0.5, 1.5 mg L−1 and CuNPs 0.01, 0.05, 0.15 mg L−1. The control group was exposed in freshwater. The results indicate that AgNPs and CuNPs exposure negatively influenced survival; body length and mass; and morphology and physiology of the epidermis, gills, and liver of Siberian sturgeon larvae. Fish exposed to AgNPs and CuNPs showed similar pathological changes: irregular structure and pyknotic nuclei of epidermis, aplasia and/or fusion of lamellae, telangiectasis, epithelial necrosis and lifting of the gills, dilation of sinusoidal space, overfilled blood vessels, and pyknotic nuclei of the liver. Fish exposed to CuNPs only demonstrated hyaline degeneration in the gills epithelium and liver. The study shows that CuNPs were more toxic to Siberian sturgeon larvae than AgNPs.

Technical note: Production of tetraploid sturgeons.

Studies and practical application of androgenesis and gynogenesis in sturgeon are significantly hindered by strong influence of ploidy restoration treatment on survivability of progeny; therefore, developed method of production of tetraploid broodstock and, consequently, use of their diploid gametes might help to avoid ploidy restoration treatment. In the present study, for the first time was developed a protocol for tetraploidy induction in 2 model sturgeon species, sterlet () and Siberian sturgeon (). A high efficiency of treatment was achieved by optimization of heat shock using a temperature of 37°C for 2 min timed between the end of female pronuclei formation and the beginning of pronuclei migration, that is, 0.8 to 1.0 τ (duration of 1 mitotic cycle during the period of synchronous cleavage division). Fertilized eggs developed in tetraploid larvae, up to 31 (89.6% in control) and 34% (70.9% in control) in sterlet and Siberian sturgeon, respectively. Most of the tetraploid larvae exhibited body malformations; as a result, consequent large scale study revealed high larval mortality, which drastically decreased after 2 mo of age. Consequent comparison of BW, length, and malformation rate and mortality between diploid and tetraploid progeny of sterlet did not reveal significant differences in fitness of diploid and tetraploid juveniles at 9 and 11 mo of age. The present study can be considered the first step towards improving the androgenesis methods of conservation of endangered sturgeons as well as understanding the sturgeon sex determination system through induction of mitotic gynogenesis.

STATUS AND PROSPECTS OF BREEDING STURGEON AT JST "SHIROKOLSKI FISH FARM"

Aim. Tthe article presents the results of breeding broodstock of sturgeon in the Shirokolski fish farm. The volume of commodity output reached 50 tonnes of sturgeon, and two tones black caviar. After drilling termal well volume growth may reach 100 t, obtaining food caviar 5 t. Location. Russian Federation, Dagestan Republic. Methods. We used the standard ichthyological research methodology. Results. At the present time the plant formed one of the largest sturgeon broodstock total biomass of more than 50 t, which include clean lines: Beluga, Russian and Siberian sturgeon, sterlet, paddlefish, and hybrid forms. The plant research for the early detection of sex by ultrasound scan. The main role of bester, which is used to obtain the food caviar. The biomass of the herd is about 30 tonnes per year is about 10 tons of breeders. Mature females Bester in our conditions in 7-8 years. Sterlet is used as producers for the purpose of reproduction and food caviar. Maintenance of broodstock is 6000 fishes and approximately 2000 breeders of medium weight from 1.5 to 6.0 kg. Mature female starlet at age 4- 5 years. Main conclusions. The results convince us that the development of sturgeon aquaculture is one of the feasible ways not only to increase employment and reduce social poaching, but also stabilizing the feedstock, substantial improvements in the efficiency of hatcheries and processors.

Effects of propofol and carbon dioxide on acid-base balance in Siberian sturgeon.

The aim of this study was to compare physiological responses in Siberian sturgeon (Acipenser baeri) induced by propofol and CO2 anaesthesia. Two procedures were applied during the experiment. In procedure I, blood samples were collected immediately after exposure (1, 2, 5, 10 min) to the anaesthetic. In procedure II, fish were exposed to the anaesthetic for 10 minutes and then were moved to anaesthetic free water. Blood was sampled after 5, 10, 20 or 30 min of recovery time. Gasometrical and biochemical analyses were performed on collected blood. In CO2 anaesthetized fish strong hypercapnic acidosis was revealed. The drop of the HCO3-/CO2 ratio, from 28:1 in control fish up to 4:1 in CO2 anaesthetized ones, proved that the compensation mechanism is not capable of preventing acidosis during CO2 anaesthesia in Siberian sturgeon. In contrast, only moderate, respiratory acidosis occurred in sturgeons anaesthetised with propofol. Hypercapnic acidosis during CO2 anaesthesia was followed by a fourfold increase of ammonia level in the blood. Glucose level, increasing only during recovery time, indicates that a secondary stress response occurred when awareness of anaesthetized fish had been restored.

Transcription of growth hormone mRNA as a molecular marker of egg quality in Siberian sturgeon (Acipenser baerii)

The Siberian sturgeon (Acipenser baerii) is an economically important species. Sturgeon stockassessment during fingerling production is considered to be one of the most difficult phases ofhatchery rearing. The present study investigated the expression of growth hormone (GH)mRNA in unfertilized eggs, fertilized eggs, eyed eggs (2 day before hatching), non-viable eggsand newly-hatched Siberian sturgeon. Knowledge about the expression of GH during egg andembryo development can help determine the quality of the eggs. This can help predict larvalviability and, to some extent, directly determine the growth and survival of young fish. Little isknown about the effect of this hormone on egg quality in sturgeon. The present study analyzedrelative GH mRNA expression using the 2-ΔΔCT method. Ribosomal protein L6 (RPL6)transcripts were used as the housekeeping gene for normalization of GH mRNA transcription.The highest levels of GH mRNA were found in eyed eggs and the lowest levels were detected innon-viable eggs (P< 0.05). These findings suggest GH mRNA as a potential marker for eggquality in Siberian sturgeon.

Characterization of Siberian sturgeon (Acipenser baerii, Brandt 1869) sperm obtained out of season

The aim of this study was to characterize and compare the basic parameters of Siberian sturgeon (Acipenser baerii) milt and sperm motility of semen collected in December and April. In addition, the suitability of semen was determined for short-term storage and cryopreservation. Sperm collected in December was characterized by an unusually high percentage of spontaneous motility (40%) as opposed to semen collected in April (5%). Sperm from December was characterized by a low sperm concentration (0.19 × 109 ml−1), high protein concentration (0.86 mg ml−1) and pH (8.7) of seminal plasma in comparison with sperm obtained in April (1.21; 0.38; 8.41, respectively). Semen obtained in December could be successfully short-term stored and cryopreserved. The fertilizing ability of cryopreserved sperm from December determined by the hatching rate was similar to that from April (22% and 29%, respectively). The results suggest that the quality of semen parameters stabilizes in sturgeons during reproductive maturity. Methods of short- and long-term storage (cryopreservation) of sperm obtained in December can be implemented for the artificial reproduction of Siberian sturgeon.

Effect of season on proteases and serine protease inhibitors of Siberian sturgeon (Acipenser baeriiBrandt, 1869) semen

Electrophoretic profiles of proteolytic activity, acrosin and protease inhibitors were studied in the semen of Siberian sturgeon, Acipenser baerii, collected in December 2012, February and April 2013. The use of gelatin zymography allowed the demonstration of the presence of numerous metalloproteinases with a molecular weight of 59-64 kDa and serine proteinase with a molecular weight of 36–49, 82, 140 and 144 kDa. These profiles were affected by the time of semen collection; seminal plasma from December was characterized by higher (P < 0.05) anti-trypsin activity (87.33 ± 17.05 U L−1) in comparison to February (12.61 ± 1.43 U L−1) and April (12.42 ± 2.71 U L−1). Electrophoretic profiles of this activity revealed the presence of several bands affected by season. Western blot analysis revealed the presence of bands recognized by anti-acrosin antibodies. The results suggest that the proteolytic system is involved in the spermatogenesis and sperm maturation of sturgeons. Proacrosin-acrosin system is likely present in sturgeon spermatozoa.

Cryopreservation of Siberian sturgeon (Acipenser baerii , Brandt, 1869) and sterlet (Acipenser ruthenus , Linnaeus, 1758) semen and its influence on sperm motility parameters assessed using a computer-assisted sperm analysis (CASA) system

Using a computer assisted sperm analysis (CASA) system, sperm motility parameters were determined in semen of the Siberian sturgeon (Acipenser baerii) and sterlet (Acipenser ruthenus) prior to and after cryopreservation. Semen was collected from 15 Siberian sturgeon and 15 sterlet males, diluted 1:1 (sperm:freezing medium) in 23.4 mm sucrose, 0.25 mm KCl, 30 mm Tris (pH of 8.0) and 10% methanol, loaded in 0.25 ml straws and frozen over liquid nitrogen vapor. Post-thaw sperm motility was activated in 10 mm Tris buffer (pH 8.5), containing 20 mm NaCl and 2 mm CaCl2. A significant decrease in the percentage of motile sperm (MOT: from 41.3% to 25.3%), curvilinear velocity (VCL: from 121.9 to 112.2 μm s−1), amplitude of lateral head displacement (ALH: from 10.4 to 5.4 μm) and momentum (MOM: from 4591 to 1038 m s−1) was observed as effect of the cryopreservation process in the Siberian sturgeon semen. A significant decrease in the values of most CASA parameters, including MOT, VAP, VCL, VSL, ALH and MOM, were also noted following the cryopreservation of sterlet semen. In the sterlet, an additional decrease in VAP (from 102.4 to 80.3 μm s−1) and VSL (from 86.8 to 69.8 μm s−1) values was noted after cryopreservation when compared to fresh semen. Unfortunately, the cryopreservation of semen from both species led to a drop in CASA parameters, which are important to the successful fertilization of eggs. MOT and VCL parameters were the most affected in these species. They can be used as sensitive criteria to check changes in motility.

Influence of acid phosphatase and arylsulfatase inhibitor additions on fertility rate of Siberian sturgeon (Acipenser baerii Brandt, 1869)

Acid phosphatase and arylsulphatase are present in the semen of many animal species, including fish. The presence of these two enzymes has also been confirmed in the semen of Siberian sturgeon (Acipenser baerii). The aim of this study was therefore to determine the potential role of acid phosphatase and arylosulphatase in the fertilization process. Tested were the additions of ammonium molybdate (acid phosphatase inhibitor) and AgNO3 (arylsulphatase inhibitor) regarding their effects on the sperm motility spermatozoa rate and the fertilization rate (in two inhibiting variants: enzymes present in spermatozoa, sperm treated; enzymes present in spermatozoa and eggs, sperm + eggs treated). There was no significant deterioration in motility parameters with either of the applied inhibitors. Ammonium molybdate caused a significant decrease in the fertilization rate (sperm + treated eggs from 86.1 to 9.5%); AgNO3 added only to spermatozoa resulted in a complete inhibition of fertilization. Results indicate that the acid phosphatase activity in eggs and arylsuphatase activity in sperm are necessary for the fertilization process in the Siberian sturgeon.

Effect of Exhaustive Exercise on the Swimming Capability and Metabolism of Juvenile Siberian Sturgeon

AbstractThis study investigated the effect of exhaustive exercise on the swimming performance of Siberian Sturgeon Acipenser baeri and on the time required for recovery. Critical swimming speed (Ucrit), maximum metabolic rate (MMR), speed coefficient (c), and excess postexercise oxygen consumption (EPOC) were measured on three groups of juvenile sturgeon by stepped velocity tests at 20°C in a fish respirometer. After a recovery period of 1 h (group 1), 1 d (group 2), or 1 week (group 3), the four parameters were determined a second time and the results compared. The Ucrit of the sturgeon was 3.26 ± 0.11 body lengths per second (mean ± SE). After a 1 h recovery period, Ucrit was 78% of its initial value and complete recovery required slightly more than 1 d. Recovery of MMR followed the same pattern. The speed exponent (c) was approximately 1.0, indicating that the Siberian Sturgeon is an efficient swimmer; swimming efficiency decreased after exhaustive exercise and the effect appeared to last for at least 1 week. Exhaustive exercise strongly hindered anaerobic swimming in Siberian Sturgeon for more than an hour.

Molecular cloning, expression analysis, and appetite regulatory effect of peptide YY in Siberian sturgeon (Acipenser baerii)

Peptide YY (PYY) is an anorectic brain–gut peptide involved in feeding regulation and well characterized in mammals. However, the functional role of PYY in the appetite regulatory of fish is not clear. In this study, we characterized a high conservation of PYY cDNA and found high expression levels of PYY mRNA in the brain and digestive tract of Siberian sturgeon. Then, we examined preprandial (pre- and post-feeding) changes of PYY mRNA expression in the brain that showed a significantly increased in 3h post-feeding, suggesting an anorectic possible function of PYY in Siberian sturgeon. Next, we examined the expression of PYY mRNA during 15days fasting and refeed after fasting. The SsPYY mRNA expression of unfed fish had a significant 2.4, 1.7, 2.0, 2.2, and 2.1-fold decrease compared to 1-, 3-, 6-, 10- and 15-day ad libitum fed animals, respectively. After refeed, SsPYY mRNA significantly increased 1.9 and 4.1-fold above that of the 15-day fed and unfed fish control group (P<0.01). Furthermore, a single intraperitoneal injection of 10, 100 and 200ng/g BW SsPYY1–36 caused a reduction in the next feeding and no significant reduction in food intake was observed in fish injected with a 1ng/g BW. Overall, PYY has a potentially role in food intake attenuation of Siberian sturgeon.

Effects of poly-β-hydroxybutyrate on metabolic diversity of anaerobic bacteria of Siberian sturgeon (Acipenser baerii) fingerlings hindgut

Effects of poly-β-hydroxybutyrate on metabolic diversity of anaerobic bacteria of Siberian sturgeon (Acipenser baerii) fingerlings hindgut

New extender for cryopreservation of Siberian sturgeon (Acipenser baerii) semen

The goal of this study was to develop a simple glucose–methanol extender for cryopreservation of Siberian sturgeon (Acipenser baerii) semen. Semen quality was assessed by determining post-thaw sperm motility and fertilizing ability at hatching stage. We tested the effect of glucose concentration (0, 0.10, 0.15, 0.20 and 0.30M) in a methanol extender on post-thaw sperm motility. Sperm motility parameters and fertilizing ability of semen cryopreserved in 0.1M glucose in 15% methanol (GM) were compared to previously described Tris–sucrose–KCl in 10% – methanol extender (TSKM). Additionally, sperm motility and fertilizing ability in relation to 30min equilibration in GM extender before cryopreservation and 30min of post-thaw storage were determined. The beneficial effect of the glucose for semen cryopreservation was related to its concentration with a quite narrow optimum of 0.1 to −0.15M. The fertilization rates of frozen/thawed sperm were similar for both (TSKM and GM) tested extenders. The sperm motility and fertilization rate were not affected either by 30min equilibration in GM extender or by 30min of post-thaw storage. Our work indicates that the use a simple extender consisting of 0.1M glucose in 15% methanol can be an alternative cryopreservation method to those previously described for sturgeons. The use of an equilibration period and the possibility of post-thaw semen storage can improve organization of hatchery work and help with logistics of large-scale hatchery operations.

Temperature adaptations of enzymes of a mucous membrane of intestines of Russian and Siberian sturgeons and their hybrid

In work temperature adaptations of enzymes of a mucous membrane of intestines of Russian, Siberian sturgeons and their hybrid ROLO are investigated. It is confirmed that temperature adaptations of digestive system poikilothermic organisms are realised mainly thanks to reorganisations of fermental systems. The assumption that evolutionary adaptation of hydrolytic function of intestines of fishes to temperature conditions of an inhabitancy takes place, apparently, is made.

Functional C1q is present in the skin mucus of Siberian sturgeon (Acipenser baerii).

The skin mucus of fish acts as the first line of self-protection against pathogens in the aquatic environment and comprises a number of innate immune components. However, the presence of the critical classical complement component C1q, which links the innate and adaptive immune systems of mammalians, has not been explored in a primitive actinopterygian fish. In this study, we report that C1q is present in the skin mucus of the Siberian sturgeon (Acipenser baerii). The skin mucus was able to inhibit the growth of Escherichia coli. The bacteriostatic activity of the skin mucus was reduced by heating and by pre-incubation with EDTA or mouse anti-human C1q antibody. We also detected C1q protein in skin mucus using the western blot procedure and isolated a cDNA that encodes the Siberian sturgeon C1qC, which had 44.7-51.4% identity with C1qCs in teleosts and tetrapods. A phylogenetic analysis revealed that Siberian sturgeon C1qC lies at the root of the actinopterygian branch and is separate from the tetrapod branch. The C1qC transcript was expressed in many tissues as well as in skin. Our data indicate that C1q is present in the skin mucus of the Siberian sturgeon to protect against water-borne bacteria, and the C1qC found in the sturgeon may represent the primitive form of teleost and tetrapod C1qCs.

Isolation and transplantation of sturgeon early-stage germ cells

We report, for the first time, a series of baseline techniques comprising isolation and transplantation of female and male early-stage germ cells in sturgeon to generate a germline chimera as a potential tool for surrogate reproduction and gene banking. Cells were dissociated from testis, characterized by mostly spermatogonia, and from ovary, exclusively comprising oogonia and previtellogenic oocytes, of Acipenser baerii, using 0.3% trypsin (2 hours, 23 °C) dissolved in PBS, isotonic with blood plasma. The dissociated germ cells were sorted by Percoll gradient centrifugation followed by immunolabeling with germ cell–specific vasa antibody DDX4, while 10% to 30% Percoll solution contained 79.4% and 70.8% labeled testicular and ovarian cells. Sorted germ cells were transplanted into a cavity close to a presumptive genital ridge of newly hatched heterospecific Acipenser ruthenus larvae with fluorescein isothiocyanate–labeled endogenous primordial germ cells. The transplanted germ cells were randomly distributed in the body cavity through 30-day posttransplantation (dpt). Subsequently, the cells were organized into genital ridges 50 dpt and proliferated 90 dpt. The number of both transplanted and endogenous germ cells significantly increased from 18.1, 22.2, and 29.1 (30 dpt) to 108.5, 90.8, and 118.5 (90 dpt) in ovarian, testicular, and endogenous germ cells, respectively (P < 0.05). The efficiency of transplantation was 60% (counted 90 dpt).

The impact of dietary DHA/EPA ratio on spawning performance, egg and offspring quality in Siberian sturgeon (Acipenser baeri)

The effect of different docosahexaenoic acids (DHAs)/eicosapentaenoic acids (EPAs) on the reproductive performance and offspring quality of Acipenser baeri was evaluated in a 6-month trial. Two isonitrogenous and isolipidic diets with different DHAs/EPAs of 1:1.9 and 1.9:1 were designed, and named after high EPA (HE) diet and high DHA (HD) diet. Stocking density was 12 kg/m2, and 136 female fish were randomly divided into two groups of 68 fish per group. After a 6-month feeding period, the hybridization was conducted among maturing female A. baeri and male A. schrencki. The broodstock performance was recorded and 6000 larvae from each group were cultured to evaluate the growth performance. Compared with the HE females, the egg mass weight, fecundity and fertilization rate in HD groups increased 40.8%, 22.3% and 35.6% respectively. Serum estradiol (E2), 11-keto-testosterone and luteinizing hormone (LH) in HD females were significantly higher than those in HE females (P < 0.05). Eggs of females fed HD diet had almost double EPA, DHA and total polyunsaturated fatty acid (PUFA) to HE eggs. Thirty-five-day post-hatching larvae from females fed HD diet tended to present a better growth performance, with higher body length, body weight, weight gain and survival rate than those of larvae from HE group. The results demonstrate that feeding A. baeri female broodstock with high DHA would improve fecundity, egg hatchability, and the overall quality of the larvae.

Suppression of Stress Responses in Siberian Sturgeon, Acipenser baeri, Juveniles by the Dietary Administration of Bovine Lactoferrin

AbstractA study was performed to investigate the influence of dietary lactoferrin (LF) on growth and stress responses of juvenile Siberian sturgeon. Fish were fed six experimental diets (0, 100, 200, 400, 800, and 1600 mg LF/kg diet) for 10 wk. At the end of the experiment, fish were exposed to an acute stressor of 2‐min air exposure. The levels of cortisol, glucose, and lactate were measured before and at 1, 3, 6, 9, 12, and 24 h after stress. LF supplementation did not influence the fish growth. Cortisol and lactate, but not glucose level, were significantly affected by dietary LF. Cortisol levels in the control group rose twofold 1 h after stress and were significantly higher than that in LF groups. Moreover, the lowest level of cortisol at all sampling times (prestress and poststress) was observed in fish fed 400 mg LF/kg diet. Lactate concentrations in sturgeon fed 400 mg LF/kg markedly rose 1 h after stress, albeit changes in other LF groups were not significant. Results of this study show that dietary LF can suppress the stress responses in Siberian sturgeon, while 400 mg LF/kg diet appears to be an effective dietary level for this species to reduce stress.