Use of ultrasonic screening in aquaculture for the directed formation sturgeon and salmon fish mature stocks

The results of research work for the period from 2018 to 2023 on the use of early non-invasive functional ultrasound screening for the purpose of targeted formation of highly productive mature-brood stocks of Siberian sturgeon of the Ob, Yenisei, Baikal, Lena populations, European sterlet of the Kama population, Siberian sterlet of the Ob, Yenisei, Irtysh populations on main full-cycle industrial fish-breeding farms of Eastern and Western Siberia using water recirculation systems are presented in the article. Biotechnological methods for the formation of highly productive mature stocks using ultrasound monitoring are described. The number of individuals with pathologies and anomalies in the development of the reproductive system, liver, gallbladder and other internal organs were estimated; treatment methods were proposed. For the first time studies on the use of ultrasound for visualizing the gonads, determining the stages of maturity, detecting diseases of the heart, liver, gallbladder in salmon fish (trout, Atlantic salmon) grown in aquaculture have been carried out. For the first time ultrasound and histological studies were carried out to study the nature of “ink spots” on the skin of Siberian sturgeon Lena population from natural habitat. It was found that in the skin of sturgeon during pathology there was a growth of epidermal cells. Melanin melanocytes increased in both epidermis and dermis. At the same time there were no elastic fibers of the epidermis after painted according to Van-Gison. All these changes may indicate melanoma

Segmental paleotetraploidy revealed in sterlet (Acipenser ruthenus) genome by chromosome painting

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Use of ultrasonic screening in aquaculture for the directed formation sturgeon and salmon fish mature stocks

The results of research work for the period from 2018 to 2023 on the use of early non-invasive functional ultrasound screening for the purpose of targeted formation of highly productive mature-brood stocks of Siberian sturgeon of the Ob, Yenisei, Baikal, Lena populations, European sterlet of the Kama population, Siberian sterlet of the Ob, Yenisei, Irtysh populations on main full-cycle industrial fish-breeding farms of Eastern and Western Siberia using water recirculation systems are presented in the article. Biotechnological methods for the formation of highly productive mature stocks using ultrasound monitoring are described. The number of individuals with pathologies and anomalies in the development of the reproductive system, liver, gallbladder and other internal organs were estimated; treatment methods were proposed. For the first time studies on the use of ultrasound for visualizing the gonads, determining the stages of maturity, detecting diseases of the heart, liver, gallbladder in salmon fish (trout, Atlantic salmon) grown in aquaculture have been carried out. For the first time ultrasound and histological studies were carried out to study the nature of “ink spots” on the skin of Siberian sturgeon Lena population from natural habitat. It was found that in the skin of sturgeon during pathology there was a growth of epidermal cells. Melanin melanocytes increased in both epidermis and dermis. At the same time there were no elastic fibers of the epidermis after painted according to Van-Gison. All these changes may indicate melanoma

The Effects of Artemia Cyst Harvesting on the Salt Lake Ecosystem

В России основные запасы цист артемии и их промысел сосредоточены в Западной Сибири, где, согласно многолетней статистике, в среднем ежегодно добывается около 1100 т цист, из них в Курганской области – 180 т, на оз. Медвежье – 140 т (около 2 % от мирового промысла). Целью этого исследования было определить степень влияния промысла цист артемии на экосистему гипергалинного водоема на примере наиболее изученного оз. Медвежье. В статье проанализированы главные трофические компоненты гипергалинной экосистемы: фитопланктон, зоопланктон и зообентос. Соленость рапы озера в разные годы составляла 110-320 г/дм3. Фитопланктон в озере функционирует круглый год, характеризуется мелкоклеточностью, низкими показателями биомассы (0,76±0,24 мг/л) и суточной продукции (1,03±0,18 мгО2/л или 0,3±0,05 гС/м2), высокими показателями А/В- и Р/В-коэффициентов. Зоопланктон и зообентос представлены в основном артемией. Биомасса рачков артемии в среднем за 1995-2018 гг. составила 21,9±3,2 мг/л (219 кг/га). За этот период в озере ежегодно формировались запасы цист в среднем в объеме 114,5±14,3 кг/га, вылов составлял 23,7±3,0 кг/га (21 % от запасов). В целом по озеру годовая продукция главных компонент экосистемы фитопланктон – рачки артемии – цисты артемии находилась в следующем соотношении – 8390:2678:115 кг/га·год (75:24:1 %). Изъятие цист из озера в количестве 23,7 кг/га (0,22 % от продукции всех компонентов), ничтожно мало по сравнению с остальными составляющими биоценоза. Остаточная после промысла плотность цист, необходимая для воспроизводства популяции артемии на следующий сезон в период 1-й генерации, составляет 10 кг/га. Усредненные данные показывают, что в биоценозе оз. Медвежье после промысла остается 91 кг/га цист, т.е. в 9 раз больше указанной плотности. Данные, представленные в статье, свидетельствуют об отсутствии какого-либо значимого влияния на экосистему гипергалинного озера существующего на данный момент уровня промысла цистIn Russia, the main stocks of Artemia cysts and cyst harvesting activities are concentrated in Western Siberia. About 1,100 tons of cysts are harvested annually, including 180 tons in the Kurgan Region and 140 tons from Medvezhye Lake (about 2 % of their world harvest). The purpose of this study was to determine the degree of influence of Artemia cyst harvesting on the ecosystem of a salt lake in a case study of Medvezhye Lake. The main trophic components of the ecosystem – phytoplankton, zooplankton, and zoobenthos – were analyzed. The salinity of the brine of Medvezhye Lake varied between 110 and 320 g/dm3 in different years. Phytoplankton in the lake function throughout the year. They are characterized by small cell sizes, low biomass (0.76±0.24 mg/L) and daily production (1.03±0.18 mgO2/L or 0.3±0.05 gC/m2), and high levels of A/B and P/B coefficients. Zooplankton and zoobenthos are represented mainly by Artemia. The biomass of Artemia shrimp reached 21.9±3.2 mg/L (219 kg/ha) on average during 1995-2018. During this period, the stock of cysts formed annually in the lake was 114.5±14.3 kg/ha; the harvest was 23.7±3.0 kg/ha (21 % of the stock). The main components of the ecosystem – phytoplankton – Artemia shrimp – Artemia cysts – were produced annually in the following proportions: 8390:2678:115 kg/ha·year (75:24:1 %). The removal of 23.7 kg/ha of the cysts (0.22 % of the production of all components) from the lake is negligible compared to the other components of the ecosystem. The residual density of cysts after harvesting, which is necessary for the reproduction of the Artemia population for the next season during the 1st generation, is 10 kg/ha. Averaged data indicate that the amount of Artemia cysts left in the ecosystem of Medvezhye Lake after cyst harvesting is 91 kg/ha, i.e. 9 times greater than the minimum required density. The results reported in the present study indicate that the current level of cyst harvesting cannot have any significant impact on the ecosystem of the hypersaline lak

Segmental paleotetraploidy revealed in sterlet (Acipenser ruthenus) genome by chromosome painting

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Population genetic structure and phylogeography of sterlet (Acipenser ruthenus, Acipenseridae) in the Ob and Yenisei river basins

The sterlet (Acipenser ruthenus Linnaeus, 1758) is a relatively small sturgeon widely distributed in Eurasian rivers from the Danube to the Yenisei. During the twentieth century, all wild sterlet populations have declined due to anthropogenic factors including: overfishing, poaching, construction of dams, and pollution. Despite the necessity of characterization both wild and captive stocks, few studies of population genetics have been performed thus far. Here we studied the genetic diversity and geographic structure of sterlet populations across the eastern range – Ob-Irtysh and Yenisei basins – by sequencing a 628-bp fragment of mitochondrial DNA control region. We identified 98 new haplotypes, delineated 12 haplogroups and estimated the time of basal haplogroup divergence within the species as over 8 million years ago. Our data suggest that Ob-Irtysh and Yenisei populations are isolated from each other and much lower genetic diversity is present in the Yenisei population than in the Ob-Irtysh population. Our data imply that sterlet populations in Siberian rivers underwent bottleneck or fragmentation, followed by subsequent population expansion. The data obtained here are important for sterlet population monitoring and restocking management

Segmental paleotetraploidy revealed in sterlet (Acipenser ruthenus) genome by chromosome painting

BACKGROUND: Acipenseriformes take a basal position among Actinopteri and demonstrate a striking ploidy variation among species. The sterlet (Acipenser ruthenus, Linnaeus, 1758; ARUT) is a diploid 120-chromosomal sturgeon distributed in Eurasian rivers from Danube to Enisey. Despite a high commercial value and a rapid population decline in the wild, many genomic characteristics of sterlet (as well as many other sturgeon species) have not been studied. RESULTS: Cell lines from different tissues of 12 sterlet specimens from Siberian populations were established following an optimized protocol. Conventional cytogenetic studies supplemented with molecular cytogenetic investigations on obtained fibroblast cell lines allowed a detailed description of sterlet karyotype and a precise localization of 18S/28S and 5S ribosomal clusters. Localization of sturgeon specific HindIII repetitive elements revealed an increased concentration in the pericentromeric region of the acrocentric ARUT14, while the total sterlet repetitive DNA fraction (C(0)t30) produced bright signals on subtelomeric segments of small chromosomal elements. Chromosome and region specific probes ARUT1p, 5, 6, 7, 8 as well as 14 anonymous small sized chromosomes (probes A-N) generated by microdissection were applied in chromosome painting experiments. According to hybridization patterns all painting probes were classified into two major groups: the first group (ARUT5, 6, 8 as well as microchromosome specific probes C, E, F, G, H, and I) painted only a single region each on sterlet metaphases, while probes of the second group (ARUT1p, 7 as well as microchromosome derived probes A, B, D, J, K, M, and N) marked two genomic segments each on different chromosomes. Similar results were obtained on male and female metaphases. CONCLUSIONS: The sterlet genome represents a complex mosaic structure and consists of diploid and tetraploid chromosome segments. This may be regarded as a transition stage from paleotetraploid (functional diploid) to diploid genome condition. Molecular cytogenetic and genomic studies of other 120- and 240-chromosomal sturgeons are needed to reconstruct genome evolution of this vertebrate group