Acipenser baerii (Siberian sturgeon) is native to Kazakhstan and is currently endangered and is listed within the first class of protected animals. Sturgeon aquaculture is becoming an important tool for the recovery of this endangered species. Nonetheless, diseases involving typical symptoms of skin ulceration and systemic bacterial hemorrhagic septicemia have occurred in cultured A. baerii on a fish farm located in Western Kazakhstan. In this study, an infectious strain of bacteria isolated from an ulcer of diseased A. baerii was identified as Aeromonas salmonicida (strain AB001). This identification involved analyses of 16S rRNA, gyrB, rpoD, and flaA genes’ sequences. Even though strain AB001 belongs to A. salmonicida, it exhibited noticeable mobility and growth at temperatures of ≥37 °C. Profiling of virulence genes uncovered the presence of seven such genes related to pathogenicity. Antibiotic sensitivity testing showed that the strain is sensitive to aminoglycosides, amphenicols, nitrofurans, quinolones, and tetracyclines. Half-lethal doses (LD₅₀) of strain AB001 for Oreochromis mossambicus and A. baerii were determined: respectively 1.7 × 10⁸ and 7.2 × 10⁷ colony-forming units per mL. The experimentally induced infection revealed that strain AB001 causes considerable histological lesions in O. mossambicus, including tissue degeneration, necrosis, and hemorrhages of varied severity.

Aeromonas spp. are opportunistic pathogens that are widely distributed in water sources, with several species being associated with fish and human diseases. We have previously identified an Aeromonas AB005 isolate from diseased Acipencer baerii. This isolate was identified as A. hydrophila based on the 16S rRNA and gyrB gene sequences. However, this novel strain does not produce indole and tested negative for ornithine decarboxylase and d-xylose fermentation—differences that set it apart from typical A. hydrophila strains. In the present study, this strain was subjected to whole-genome sequencing and compared with the genomes of the type strain (Aeromonas hydrophila ATCC 7966^T) and other Aeromonas spp. Comprehensive genome analysis suggests that AB005 represents a distinct species within the genus. The draft genome of the AB005 strain comprises 4,780,815 base pairs with a GC content of 61.2% and contains 6104 predicted protein-coding sequences along with numerous genes implicated in antibiotic resistance. The core/pan-genome analysis reveals extensive genetic diversity, indicative of a dynamic genomic structure. These findings collectively underscore the taxonomic distinction of the AB005 strain as a novel species and highlight its potential pathogenic implications in aquaculture and public health settings.

Fish tagging is a necessary part of many production processes when growing in regulated systems. This article presents the results of research work on tagging sturgeon fish grown in artificial conditions of recirculating aquaculture systems (RAS). The most important advantages of using this method are biological safety, efficiency and non-traumatic. Fish tagging methods are mainly used in the cultivation of sturgeon species (beluga, ship sturgeon, russian sturgeon, siberian sturgeon, sterlet, etc.), which are necessary for many production processes, including: harvesting of producers, selection of fish for spawning companies, breeding work with repair and breeding stock, determination of viability in sturgeon farms. For successful tagging of sturgeon fish, the article presents the most effective places of the studied area and methods of tagging. An example of the correct position of the chip sensor of the passive integrated transponder (PIT mark) when administered with a syringe-injector is presented, as well as the results of alternative methods of tagging sturgeon fish. The optimal location of the workplace during fish tagging is also described. The results of the study are aimed at determining the most effective method of tagging, which contributes to effective and efficient work in the cultivation of sturgeon fish in the RAS. Key words: aquaculture, sturgeon fish, tagging, wintering, RAS. Балықтарды жасанды ортада өсіру кезінде таңбалау жұмыстары көптеген өндірістік процесстердің негізгі элементтерінің бірі болып табылады. Бұл мақалада жасанды ортадағы тұйық жүйелі сумен қамтамасыз ету қондырғылары (ТЖСҚЕҚ) жағдайында өсірілген бекіретұқымдас балықтарын таңбалау бойынша жүргізілген зерттеу жұмыстарының нәтижелері келтірілген. Бұл аталған әдістемені қолданудың артықшылығы болып биологиялық қауіпсіздігі, жылдам және жарақаттамайтындығы. Таңбалау әдістемелері әсіресе бекіретұқымдас балық түрлерін (қортпа, пілмай, орыс бекіресі, сібір бекіресі, сүйрік және т.б.) өсіруде қажетті өндірістік процесстер кезінде, соның ішінде: өндіргіштерді дайындауда, уылдырықтату компаниясына балықтарды іріктеу кезінде, жұмысшы-аналық үйірлерін асылдандыру жұмыстары кезінде, бекіретұқымдас балықтарды өсіру шаруашылықтарындағы балықтардың өміршеңділігін анықтау негізінде қолданылады. Мақалада бекіретұқымдас балықтарды сәтті таңбалауды жүргізу үшін балық денесінің зерттелетін тиімді орындарымен тиімді әдістемелері келтіріліп сипатталған. Бекіретұқымдас балықтарға микросхемалы пассивті интеграцияланған транспондер (ПИТ-таңбалы) датчиктерін шприц-инжектор көмегі арқылы дұрыс орналастырудың және таңбалаудың салыстырмалы басқа да әдістемелері сипатталған. Сонымен қатар балықтарды таңбалау жұмыстарын жүргізу кезіндегі жұмыс орындарының қолайлы орналасуы келтірілген. Зерттеу жұмыстарынан алынған нәтижелерден ТЖСҚЕҚ жағдайында өсірілетін бекіретұқымдас балықтарды таңбалаудың тиімді және тез жүргізілуге сәйкесті әдісі анықталып сипатталды. Түйін сөздер: аквакультура, бекіретұқымдас балықтар, таңбалау, қыстату, ТЖСҚЕҚ. Мечение рыб является необходимым элементом многих производственных процессов при выращивании в условиях регулируемых систем. В данной статье представлены результаты исследовательских работ по мечению осетровых рыб, выращиваемых в искусственных условиях установок с замкнутым циклом водоснабжения (УЗВ). Наиболее важными преимуществами использования данного метода являются биологическая безопасность, оперативность и нетравматичность. Методы мечения рыб в основном применяются при выращивании осетровых видов рыб (белуга, шип, русский осетр, сибирский осетр, стерлядь и др.), необходимые для многих производственных процессов, включая: заготовку производителей, отбор рыб для нерестовой компании, племенную работу с ремонтно-маточным стадом, определение жизнестойкости в осетровых хозяйствах. Для успешного проведения...

The article presents the results of isolation and identification of the bacterium Aeromonas bestiarum from diseased individuals of Siberian sturgeon (Acipenser baerii) reared in recirculating aquaculture system (RAS). As a result of biochemical studies, the isolated strain A. bestiarum AB002 is characterized as: a Gram-negative, non-motile oxidase-positive bacillus capable of growing in a wide temperature range from 13 to 42 ºC. In addition, strain AB002 is characterized by the hydrolysis of gelatin and esculin, forming H2S and indole, and exhibits arginine dihydrolase activity. The analysis of bacterial resistance to antibiotics revealed that strain AB002 is resistant to multiple groups of antibiotics, including Penicillins (Oxacillin, Penicillin G, Ampicillin, Amoxicillin); Cephalosporins (Cefazolin); Macrolides (Erythromycin); Lincomycins (Lincomycin); Rifamycins (Rifampicin); Coumarins (Novobiocin). The analysis of virulence factors revealed that the pathogenic strain A. bestiarum AB002 is characterized by the presence of 6 virulence genes out of 10 studied, among which lipase (pla), cytotonic enterotoxin (alt), serine protease (ahe2), DNAase (nucl), cholesterol acyltransferase (gcaT), aerolysin (aerA) were identified.

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This study presents a molecular genetic analysis of a rosehip sample using DNA barcoding and phylogenetic approaches. The aim of the research was species identification based on comparative analysis of nucleotide sequences of nuclear and chloroplast marker genes ITS, matK, rbcL, and trn. Genomic DNA was extracted from rosehip leaves using a modified CTAB method optimized for plant material rich in polyphenolic compounds. Target DNA fragments were amplified by polymerase chain reaction using specific primer pairs. PCR products were visualized by agarose gel electrophoresis, purified, and sequenced using the Sanger method on an automated genetic analyzer. The obtained nucleotide sequences were edited, assembled into consensus sequences, and analyzed using SeqScape and MEGA software packages. Species identification was performed through sequence comparison with the GenBank database using the BLAST algorithm and by constructing phylogenetic trees. The results demonstrated 100% sequence identity of all studied genetic markers with reference sequences of Rosa majalis. Phylogenetic analysis confirmed that the investigated sample clustered with other representatives of this species within the genus Rosa. The findings indicate high diagnostic value of the selected DNA markers for reliable molecular identification of rosehip species. The integrated approach combining PCR amplification, sequencing, and phylogenetic analysis proved to be effective for taxonomic verification. The results may be applied in plant systematics, pharmacognosy, biodiversity studies, and quality control of medicinal plant raw materials.