Russian Sturgeon Research Articles

Isolation of Collagen from Marine Resources from the Black Sea.

ABSTRACT: Purpose: Evaluation of possibilities of obtaining type I fibrillar collagen from fish skin using the Black Sea marine resources and suitable cross-linking agent for this one to stay stable at body or room temperature. Materials and methods: Collagen has been extracted from the skin of the Grey mullet and Sturgeon by the acidic method with Acetic acid 0.5M. Cross-linking has been performed by using Tanic acid at 4-6°C. The rheological behaviour was determined by using a Haake VT 550 rheo-viscometer. Results: The collagen was isolated from the skin of Gray mullet and Sturgeon. (Acipenser gueldenstaedtii). Hydrogels have a pseudoplastic behavior. Tanic acid was used for cross-linking like a better alternative, eliminating the toxicity of glutaraldehyde. Conclusion. The yield of collagen extraction was higher for the Gray mullet skin, than Sturgeon. Pseudo-plastic behavior allows them to be successfully applied in the treatment of wounds. The isolated type I collagen may serve as an attractive alternative to mammalian collagen for biomedical and pharmaceutical applications.

Genetic profile analysis of aquaculture Russian sturgeon (Acipenser gueldenstaedtii) – implications for restocking measures

Genetic profile analysis of aquaculture Russian sturgeon (Acipenser gueldenstaedtii) – implications for restocking measures

Protective action of fish muscle extracts against cellular senescence induced by oxidative stress

Muscle extracts of some fish species, i.e. pike (Esox lucius), sterlet (Acipenser ruthenus), pink salmon (Oncorhynchus gorbuscha) and, to a lesser extent, perch (Perca fluviatilis) and Russian sturgeon, (Acipenser gueldenstaedtii) prevent the development of premature senescence of the human embryonic fibroblasts induced by the sublethal concentration of H2O2. Muscle extracts of other fish species tested, i.e. coho salmon (Oncorhynchus kisutch) and zander (Sander lucioperca), have not demonstrated this feature. Cell proliferation increased after the action of the senescence-inhibiting muscle extracts. Possible mechanisms of the action of nature biologically active compounds that interfere with the development of stress-induced cell senescence are discussed.

Distribution of the enzyme activity in the intestine of beluga Huso huso and Russian sturgeon Acipenser gueldenstaedtii (Acipenseridae)

Data on distribution of digestive enzymes along the intestinal tract of mature specimens of the beluga Huso huso and Russian sturgeon Acipenser gueldenstaedtii are presented. The absence of a distinct proximo-distal gradient of the enzyme activity can be explained by short length of the intestine of sturgeons. Considerable differences are found in the distribution pattern of enzymes along the intestinal tract of beluga and Russian sturgeon. The effect of the method of calculation of the enzyme activity on the data on the proximo- distal gradient is considered.

ПРОХОДНЫЕ ОСЕТРОВЫЕ (ACIPENSERIDAE, ACTINOPTERYGII) р. ДОН ВЫШЕ ЦИМЛЯНСКОГО ГИДРОУЗЛА

Based on the literature, non-published and survey data, information on the occurrence of anadromous sturgeons after the regulation of the Don River downstream and upstream of the Tsimlyansk Dam is given. There were two peaks of mature adults approaching the dam, namely, in the 1950s and 1980s. The first mass peak was associated with the wild population existed then; the second one was a result of mass artificial breeding. At the first stage, the sturgeon (Acipenser gueldenstaedtii Brandt et Ratzeburg, 1833) and beluga (Huso huso (Linnaeus, 1758)) prevailed below the dam; at the second one, just the sturgeon did. Since 1955, only 21 individuals of anadromous sturgeons were transported through the dam by a fish ladder. During 1952-1961, 1,145 individuals were transported into the reservoir, including 218 belugas. Separate beluga individuals were transported later on as well. There is evidence of the presence of young beluga individuals from natural spawning in the reservoir before the 1970s. The latest known adult sturgeon and stellate sturgeon (Acipenser stellatus Pallas, 1771) in the reservoir were noted in the 1980-90s. Separate beluga individuals have been met until now. The youngest of the noted individuals belong roughly to the generations of the early 1990s. It is concluded on the existence of an extremely low-abundant landlocked form of the Azov beluga in the reservoir.

Vitellogenin Level in the Plasma of Russian Sturgeon (Acipenser gueldenstaedtii) Northern Israel

In the present study, we examined the vitellogenin (Vg) level of Russian sturgeon maintained in a relatively constant aquaculture at a water temperature of 18-22°C during growth and maturation. An increase in Vg in the blood plasma from oocytes was found in the yellow oocytes stage to the gray oocytes stage. However, no Vg was found in the pre-vitellogenic stage. Based on the present study and previous studies on hormone control reproduction and growth, we proposed a quality model that correlated between egg development and the hormones involved in controlling vitelogenesis (VTL).

Identification and quantification of uronic acid-containing polysaccharides in tissues of Russian sturgeon (Acipenser gueldenstaedtii) by HPLC–MS/MS and HPLC–MSn

Uronic acid-containing polysaccharides (UACPs) including glycosaminoglycans (GAGs) and some non-GAGs in different tissues of Russian sturgeon were analyzed by detecting characteristic oligosaccharides in their acid hydrolysates after 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatization. Disaccharides without substituents were identified and quantified using HPLC–MS/MS with a triple quadrupole mass spectrometer, while other oligosaccharides including sulfated/acetylated disaccharides and tetrasaccharides were characterized by HPLC–MSn with a linear ion trap mass spectrometer. The results showed that the nostril, gill arch and notochord of Russian sturgeon contained high amounts of CS ranging from 1700 to 3660 mg per 100 g of dried tissues. A non-GAG UACP, named AGSP, with a backbone of →4)-GlcA(1 → 2)-Man(1→, was found in the gill arch, caudal fin and notochord of sturgeon with the contents from 37 to 227 mg per 100 g of dried tissue. Another two unknown non-GAGs, UP1 and UP2, existed in intestine and in body muscles and gill arch, respectively. And an unidentified GAG (UP3) was found in testes, ovaries, swim bladder, intestine and skin. This investigation was the first effort to determine the overall UACP species in sturgeon after extraction of the eggs and caviar production.

Evolutionary relations and population differentiation of Acipenser gueldenstaedtii Brandt, Acipenser persicus Borodin, and Acipenser baerii Brandt

Russian ( Acipenser gueldenstaedtii), Persian ( A. persicus) and Siberian ( A. baerii) sturgeons are closely related ‘Ponto-Caspian’ species. Investigation of their population structure is an important problem, the solution of which determines measures for conservation of these species. According to previous studies, ‘baerii-like’ mitochondrial genotypes were found in the Caspian Sea among 35% of Russian sturgeon specimens, but were not found in Persian sturgeons. This confirms genetic isolation of the Persian sturgeon from the Russian sturgeon in the Caspian Sea. However, in order to clarify the relationships of these species it is necessary to analyze nuclear DNA markers. The amplified fragment length polymorphism (method) allows estimating interpopulation and interspecific genetic distances using nuclear DNA markers. In the present study, four samples were compared: Persian sturgeons from the South Caspian Sea, Russian sturgeons from the Caspian Sea and the Sea of Azov, and Siberian sturgeons from the Ob’ River, which are close to the latter two species, but are also clearly morphologically and genetically distinct from them. For the amplified fragment length polymorphism (AFLP) method, eight pairs of selective primers were used. The analysis revealed that the Siberian sturgeon has formed a separate branch from the overall Persian-Russian sturgeons cluster, which was an expected result. In addition, the results showed that the Caspian Russian sturgeon is closer to the Persian sturgeon from the Caspian Sea than to the Russian Sturgeon from the Sea of Azov. The present DNA marker data confirm that despite the genetic isolation of the Persian sturgeon from the Russian sturgeon in the Caspian Sea, the Persian sturgeon is a young species.

Evolutionary relations and population differentiation of Acipenser gueldenstaedtii Brandt, Acipenser persicus Borodin, and Acipenser baerii Brandt

Russian ( Acipenser gueldenstaedtii), Persian ( A. persicus) and Siberian ( A. baerii) sturgeons are closely related ‘Ponto-Caspian’ species. Investigation of their population structure is an important problem, the solution of which determines measures for conservation of these species. According to previous studies, ‘baerii-like’ mitochondrial genotypes were found in the Caspian Sea among 35% of Russian sturgeon specimens, but were not found in Persian sturgeons. This confirms genetic isolation of the Persian sturgeon from the Russian sturgeon in the Caspian Sea. However, in order to clarify the relationships of these species it is necessary to analyze nuclear DNA markers. The amplified fragment length polymorphism (method) allows estimating interpopulation and interspecific genetic distances using nuclear DNA markers. In the present study, four samples were compared: Persian sturgeons from the South Caspian Sea, Russian sturgeons from the Caspian Sea and the Sea of Azov, and Siberian sturgeons from the Ob’ River, which are close to the latter two species, but are also clearly morphologically and genetically distinct from them. For the amplified fragment length polymorphism (AFLP) method, eight pairs of selective primers were used. The analysis revealed that the Siberian sturgeon has formed a separate branch from the overall Persian-Russian sturgeons cluster, which was an expected result. In addition, the results showed that the Caspian Russian sturgeon is closer to the Persian sturgeon from the Caspian Sea than to the Russian Sturgeon from the Sea of Azov. The present DNA marker data confirm that despite the genetic isolation of the Persian sturgeon from the Russian sturgeon in the Caspian Sea, the Persian sturgeon is a young species.

Evolutionary relations and population differentiation of Acipenser gueldenstaedtii Brandt, Acipenser persicus Borodin, and Acipenser baerii Brandt.

Russian ( Acipenser gueldenstaedtii), Persian ( A. persicus) and Siberian ( A. baerii) sturgeons are closely related 'Ponto-Caspian' species. Investigation of their population structure is an important problem, the solution of which determines measures for conservation of these species. According to previous studies, 'baerii-like' mitotypes were found in the Caspian Sea among 35% of Russian sturgeon specimens, but were not found in Persian sturgeons. This confirms genetic isolation of the Persian sturgeon from the Russian sturgeon in the Caspian Sea. However, in order to clarify the relationships of these species it is necessary to analyze nuclear DNA markers. The amplified fragment length polymorphism (method) allows estimating interpopulation and interspecific genetic distances using nuclear DNA markers. In the present study, four samples were compared: Persian sturgeons from the South Caspian Sea, Russian sturgeons from the Caspian Sea and the Sea of Azov, and Siberian sturgeons from the Ob' River, which are close to these two species, but are also clearly morphologically and genetically distinct from them. For the AFLP method, eight pairs of selective primers were used. The analysis revealed that the Siberian sturgeon has formed a separate branch from the overall Persian-Russian sturgeons cluster, which was an expected result. In addition, the results showed that the Caspian Russian sturgeon is closer to the Persian sturgeon from the Caspian Sea than to the Russian Sturgeon from the Sea of Azov. The present DNA marker data confirm that despite the genetic isolation of the Persian sturgeon from the Russian sturgeon in the Caspian Sea, the Persian sturgeon is a young species.

Gonadotropins in the Russian Sturgeon: Their Role in Steroid Secretion and the Effect of Hormonal Treatment on Their Secretion.

In the reproduction process of male and female fish, pituitary derived gonadotropins (GTHs) play a key role. To be able to specifically investigate certain functions of Luteinizing (LH) and Follicle stimulating hormone (FSH) in Russian sturgeon (Acipenser gueldenstaedtii; st), we produced recombinant variants of the hormones using the yeast Pichia pastoris as a protein production system. We accomplished to create in vitro biologically active heterodimeric glycoproteins consisting of two associated α- and β-subunits in sufficient quantities. Three dimensional modelling of both GTHs was conducted in order to study the differences between the two GTHs. Antibodies were produced against the unique β-subunit of each of the GTHs, in order to be used for immunohistochemical analysis and to develop an ELISA for blood and pituitary hormone quantification. This detection technique revealed the specific localization of the LH and FSH cells in the sturgeon pituitary and pointed out that both cell types are present in substantially higher numbers in mature males and females, compared to immature fish. With the newly attained option to prevent cross-contamination when investigating on the effects of GTH administration, we compared the steroidogeneic response (estradiol and 11-Keto testosterone (11-KT) in female and males, respectively) of recombinant stLH, stFSH, and carp pituitary extract in male and female sturgeon gonads at different developmental stages. Finally, we injected commercially available gonadotropin releasing hormones analog (GnRH) to mature females, and found a moderate effect on the development of ovarian follicles. Application of only testosterone (T) resulted in a significant increase in circulating levels of 11-KT whereas the combination of GnRH + T did not affect steroid levels at all. The response pattern for estradiol demonstrated a similar situation. FSH levels showed significant increases when GnRH + T was administered, while no changes were present in LH levels.

Who owns sturgeon in the Caspian? New theoretical model of social responses towards state conservation policy

This article explores responses to the implementation of Russian sturgeon conservation policy in three fishing communities (in Dagestan, Kalmykia and the Volga River delta areas), along the Western and Northern coasts of the Caspian Sea. Enforcement of regulatory measures has led to complex socio-cultural responses. We show how social responses to conservation policy generate various forms of poaching. An analytical model of ‘soft’ and ‘hard’ forms of poaching is analyzed against three regulatory measures: introduction of specially designated fishing areas in Russia’s Caspian fisheries, border zone expansion and the ban on sturgeon fishing. We explain why in Kalmykia the policy led people to stop practicing hard forms of sturgeon fishing, while fishermen in Dagestan responded in a more complex manner by displaying resistance towards the new policies.

Features of the effect of a complex probiotic with Bacillus bacteria and the larvae of Hermetia illucens biomass on Mozambique tilapia (Oreochromis mossambicus × O. niloticus) and Russian sturgeon (Acipenser gueldenstaedti) fry

A study of the effect of a complex probiotic preparation with bacteria of the genus Bacillus and a microdose of larvae of the fly Hermetia illucens on the physiological. parameters of fish has been carried out. It was established that introduction of the complex into artificial feeds for tilapia and Russian sturgeon juveniles during their incubation in recirculating aquaculture systems improves the digestion efficiency and increases the rate of fish growth and body mass accumulation. In tilapia, a decrease in the cholesterol level was revealed, while in sturgeon, an increase in the hemoglobin content was found. It was noted that a probiotic with biologically active agents H. illucens had a stimulating effect on the development of sexual gonads in female sturgeon fry, promoted an increase in the ovary mass, and provided for the development of eggs without morphological disturbances.

Reaction of osmoregulatory system in juveniles of Russian sturgeon Acipenser gueldenstaedtii (Acipenseridae) on influence of comatotropin of carp Cyprinus carpio

For the first time by the example of juveniles of Russian sturgeon Acipenser gueldenstaedtii Brandt, the role of growth hormone of hypophysis in the osmotic regulation of acipenserids was studied, also the process of transformation of reserve chloride was described. In Russian sturgeon juveniles, administration of growth hormone of carp Cyprinus carpio at a dose of 1 mg per 1 g body weight causes changes in the fine structure of numerous reserve (undifferentiated) gill epithelial cells and thus stimulates their transformation into mature chloride cells involved in transport of monovalent ions. Increase in the number of chloride cells, on account of reserve cells, was accompanied by higher enzymatic activity of Na+/K+-ATPase in gill homogenates of the injected fish adapting to a hyperosmotic environment of salinity 12.5‰ (403 mosm/l) than in the intact fish under the same conditions but without hormonal treatment. Morphophysiological changes observed in the injected juveniles provided the more efficient dynamics of blood serum osmolarity under saline exposure than that in the intact fish. Their serum osmolality during the maximum rise (24 hours after the transfer of fish into the water of 12.5‰ salinity) was lower (p <0.01), than that of the intact fish. The inclusion of growth hormone in the osmoregulatory process was established.

Comparative coelomic fluid composition of sterlet sturgeon Acipenser ruthenus Linnaeus, 1758, Siberian sturgeon Acipenser baerii Brandt, 1869, and Russian sturgeon Acipenser gueldenstaedtii Brandt &amp; Ratzeburg, 1833

The objectives of this study were to compare the physicochemical properties of coelomic fluid (CF) in three sturgeon species, sterlet sturgeon Acipenser ruthenus (age 5–8 years), Siberian sturgeon Acipenser baerii (age 15–20 years), and Russian sturgeon Acipenser gueldenstaedtii (age 13–18 years). For the study, CF was collected by plastic pipette from the eggs of mature female sterlet sturgeon (N = 10), Siberian sturgeon (N = 7) and Russian sturgeon (N = 4); osmolality, pH, ionic composition (Na+, K+, Ca2+, Mg2+, Cl−), glucose, cholesterol and total protein of the CF were then analyzed. Mean concentration of K+ (4.4–6.11 mmol/L), Cl− (89.8–98.0 mmol/L), Ca2+ (0.87–0.96 mmol/L), Mg2+ (0.57–0.67 mmol/L), cholesterol (0.13–0.16 mmol/L), total protein (2.41–3.57 g/L), pH (7.92–7.98), and osmolality (190–213 mOsm/kg) of CF were not significantly different among these three species. However, the mean concentration of Na+ was significantly lower in sterlet sturgeon (104.6 ± 7.7 mmol/L; p < .05) than in the Siberian (126.4 ± 6.2) and Russian (123.0 ± 5.9) sturgeon. For these three species, Na+, K+, Cl−, and Mg2+ were the dominating ions; several significant correlations were observed among these ions and other physiochemical properties of CF. This is the first report on the ionic and biochemical composition of the CF of sterlet, Siberian and Russian sturgeon, which can be used as a reference point for further development of artificial media for the short-term storage of unfertilized sturgeon eggs as well as for the standardization of the fertilization protocol for these species in controlled reproduction.

Effects of dietary lipid level and n-3/n-6 fatty acid ratio on growth, fatty acid composition and lipid peroxidation in Russian sturgeonAcipenser gueldenstaedtii

The growth performance, fatty acid composition, hepatic lipid content, hepatic somatic index and lipid peroxidation in Russian sturgeon were investigated using diets containing three lipid levels 50 g kg−1 (L5), 150 g kg−1 (L15) and 250 g kg−1 (L25) and three n-3/n-6 fatty acid ratios (1 : 3, 1 : 1 and 3 : 1) for 8 weeks. Weight gain significantly increased with the increase in dietary lipid levels at n-3/n-6 fatty acid ratios of 1 : 3 and 1 : 1, but not at the 3 : 1 ratio. Correspondingly, fish survival gradually decreased with the increase in dietary lipid at the 3 : 1 n-3/n-6 fatty acid ratio. The dietary lipid level significantly affected the composition of whole-body fatty acid. The retention of highly unsaturated fatty acid dramatically decreased at the level of 250 g kg−1 dietary lipid. The liver malondialdehyde increased with the increase in dietary lipid levels and the n-3/n-6 fatty acid ratios. The contents of lipid and triglyceride in the liver and the hepatic somatic index also increased with the increase in dietary lipid. The diet combination of L25 + 3 : 1 showed the highest aspartate transaminase and alanine transaminase, indicatives of hepatic injury. This study indicates that the L25 + 1 : 3 diet can improve fish growth performance, whereas the L25 + 3 : 1 diet may lead to poor growth performance due to high lipid peroxidation.

Growth, fatty acid composition and lipid deposition of Russian sturgeon (Acipenser gueldenstaedtii) fed different lipid sources

Aquaculture ResearchVolume 48, Issue 9 p. 5126-5132 Short Communication Growth, fatty acid composition and lipid deposition of Russian sturgeon (Acipenser gueldenstaedtii) fed different lipid sources Haoyong Zhu, Haoyong Zhu Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, ChinaSearch for more papers by this authorQi Li, Qi Li Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, ChinaSearch for more papers by this authorHewei Wang, Hewei Wang Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, ChinaSearch for more papers by this authorTingting Zhu, Tingting Zhu Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, ChinaSearch for more papers by this authorJianguang Qin, Jianguang Qin School of Biological Sciences, Flinders University, Adelaide, SA, AustraliaSearch for more papers by this authorErchao Li, Erchao Li Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, ChinaSearch for more papers by this authorLiqiao Chen, Corresponding Author Liqiao Chen lqchen@bio.ecnu.edu.cn Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, ChinaCorrespondence: L Chen, Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai 200062, China. E-mail: lqchen@bio.ecnu.edu.cnSearch for more papers by this author Haoyong Zhu, Haoyong Zhu Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, ChinaSearch for more papers by this authorQi Li, Qi Li Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, ChinaSearch for more papers by this authorHewei Wang, Hewei Wang Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, ChinaSearch for more papers by this authorTingting Zhu, Tingting Zhu Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, ChinaSearch for more papers by this authorJianguang Qin, Jianguang Qin School of Biological Sciences, Flinders University, Adelaide, SA, AustraliaSearch for more papers by this authorErchao Li, Erchao Li Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, ChinaSearch for more papers by this authorLiqiao Chen, Corresponding Author Liqiao Chen lqchen@bio.ecnu.edu.cn Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai, ChinaCorrespondence: L Chen, Laboratory of Aquaculture Nutrition and Environmental Health (LANEH), School of Life Sciences, East China Normal University, Shanghai 200062, China. E-mail: lqchen@bio.ecnu.edu.cnSearch for more papers by this author First published: 07 July 2016 https://doi.org/10.1111/are.13148Citations: 4Read 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 Volume48, Issue9September 2017Pages 5126-5132 RelatedInformation

Growth performance, lipid requirement and antioxidant capacity of juvenile Russian sturgeonAcipenser gueldenstaedtifed various levels of linoleic and linolenic acids

To evaluate the effects of dietary linoleic (LA) and linolenic acids (LN) on growth, enzyme activities to lipid addition and antioxidant capacity of the Russian sturgeon, Acipenser gueldenstaedti, 10 diets with different sources of lipid were formulated. Coconut oil in the basal diet was replaced by sunflower oil to make three diets (LA0.5 + LN0, LA1.0 + LN0 and LA2.0 + LN0) with dietary LA at 0.5%, 1.0% and 2%, by perilla oil to obtain three diets (LA0 + LN0.5, LA0 + LN1.0 and LA0 + LN2.0) with dietary LN at 0.5%, 1.0% and 2%, and by the combination of sunflower oil and perilla oil to provide three diets (LA0.25 +LN0.25, LA0.5 + LN0.5 and LA1.0 + LN1.0) containing LA and LN at 0.25, 0.50 and 1.00%. Coconut oil was used as the control diet at 10%, but without LA and LN (LA0 + LN0). After feeding for 56 days, the fish whole body, the serum and the liver of sturgeon were sampled. Fish fed LA0 + LN0 and LA0 + LN2.0 gained lowest weight but was not significantly different from the fish fed LA0 + LN1.0. Fish fed LA1.0 + LN1.0 gained highest weight among all groups. Feed conversion ratio was the best in fish fed LA1.0 + LN1.0. Survival, condition factor and viscerosomatic index did not differ among treatments. Total body n-6 fatty acids increased with the levels of n-6. Total body n-3 fatty acids also increased with dietary n-3, and fish fed 2.0% LN had the highest content of total body n-3 fatty acids among all groups. Triglyceride and cholesterol in the serum of fish fed LA1.0 + LN1.0 were lowest. Fish fed LA1.0 + LN1.0 showed the highest lipoprotein lipase and lipase activities, but the lowest malate dehydrogenase activity. Fish fed LA1.0 + LN1.0 showed higher catalase, superoxide dismutase activity and total antioxidant capacity than fish fed other diets. This study indicates that diets containing both LA and LN are best for the growth of Russian sturgeon. The level of LA1.0 + LN1.0 in the diet is most beneficial for growth performance and antioxidant capacity in juvenile Russian sturgeon.

Change in Sox9 protein localization through gonad development in Russian sturgeon (Acipenser gueldenstaedtii)

The Russian sturgeon is a highly prized species reared in aquaculture. The process of gonad development in this critically endangered species is poorly understood. The aim of this study was to describe the localization of Sox9 protein during gonad development of the Russian sturgeon from the day of hatching to the 1440 day post hatching (dph). The larvae at age 1, 10, 25 dph and prepared gonads of 300, 720, 1440 dph individuals were immunohistochemistry-stained for Sox9 detection. Sox9-positive regions were detected in larvae in primordial germ cells cytoplasm. Analysis of 300 dph sturgeon gonads revealed the presence of the Sox9 protein in cytoplasm of some oocytes in the chromatin nucleus stage. In testes at 720 dph, Sox9 was observed in the cytoplasm of type A and early B spermatogonias. In the ovaries, Sox9 was observed in the cytoplasm of diplotene oocytes and prefollicular cells. In testes of 1440 dph sturgeon, Sox9 was present in the nucleus of the spermatocytes and in types A and B spermatogonias cytoplasm. Analysis of ovaries at 1440 dph reveals multiple diplotene oocytes with a Sox9-positive cytoplasm. Furthermore, in 720 and 1440 dph, sturgeon presence of intersexual gonads was detected. In intersex gonads, Sox9 was observed in the cytoplasm of diplotene oocytes and type A spermatogonias. This study may be the first attempt to determine Sox9 protein localization during ontogenesis of the Russian sturgeon. Localization of Sox9 protein may become a useful marker of the maturation level in testis of the Russian sturgeon.

Comparative anatomy of pectoral girdle and pectoral fin in Russian sturgeon and American paddlefish

Acipenseriformes occupy an important place in the evolutionary history. Skeleton of their pectoral fins has elements related to teleosts, but also to tetrapods. This article summarises and compares anatomical structure of the pectoral girdle and pectoral fin of Russian sturgeon (Acipenser gueldenstaedtii) and American paddlefish (Polyodon spathula). These species possess pectoral fins with some distinctive features in their structure. The pectoral girdles are composed of both cartilaginous and ossified elements. Unlike sturgeons, American paddlefish does not have an interclavicle and suprascapular cartilage. Moreover, its cleithrum doesn't form medially directed lamina. The quantity of the proximal radials in the investigated fish species are not the same. The dorsal and ventral muscles, which act on the pectoral fin of Russian sturgeon and American paddlefish, are not equally developed. In our opinion, this is caused by the differences in the mode of life, motility of fins, as well as by stabilisation of body during swimming.