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In the context of global climate change, which influences the availability of water resources for use in aquaculture and agriculture, impacting food production and ensuring food security. Recent studies have reported promising results in fish farms and hatcheries despite the challenges of adopting cost-effective approaches to mitigation and adaptation to climate change in practice. The study aimed to evaluate the adaptation of sturgeon broodstock to climate change conditions, reared in a floating cage. A number of 165 specimens of the species Acipenser gueldenstaedtii (Brandt & Ratzenburg, 1833), with an average mass of 1000 g/fish, were reared in a 5x5x3 m cage made of galvanized panels and located in the CM Lunca irrigation canal. At the end of the experimental period, after 45 days, the results showed an individual growth of 800 g and an adequate health status due to the adaptability of this species to the conditions of sturgeon broodstock rearing under climate changes. [ABSTRACT FROM AUTHOR]

An important stage in artificial reproduction in fish of the families Acipenseridae and Cyprinidae is the elimination of adhesiveness of egg process. International studies recommended a variety of substances used against adhesiveness of eggs but do not differentiate the major advantages and disadvantages of their use. The present experiment aimed to determine the effects of de-adhesion with mineral silt, talcum and tannin. The final results regarding the effect of the substances used for deadhesion on embryogenesis were determined by qualitative assessments, and the fungal infestation was quantitatively quantified by the percentages of fish eggs infested with Saprolegnia sp. in relation to the fertilization percentages. The present work emphasizes that the use of tannin for de-adhesion of fish eggs (B3) not only provides medium-good transparency in embryogenesis, but also reduces the risk of fungal infestation by 12.55% compared to de-adhesion with silt (B1), 13,56% with talcum (B2), with comparable fertilization percentages of 87% in B1, 86.9% in B2 and 89.4% in B3, which recommends it for deadhesing of eggs and reducing fungal attacks in aquaculture. [ABSTRACT FROM AUTHOR]

The experiment aimed to evaluate the plasticity of juvenile Russian sturgeon (Acipenser gueldenstaedtii, J. F. Brandt & Ratzeburg, 1833) reared in a floating cage located on a pond. The biological material was 1400 juvenile Russian sturgeon with a mean weight of 9 g/fish and 40 days of age. The intensive rearing system was a 5x5x3 m floating cage in a pond. The fish were fed NUTRA MP-L extruded feed containing 52% crude protein and 20% fat three times a day. The experimental results showed a 64% survival of Russian sturgeon juveniles and the evaluation of productive bioindicators demonstrates high technological plasticity at 50% of the tested group. From the analysis of rearing conditions (environmental and technological), it was concluded that Russian sturgeon juveniles show a certain degree of plasticity depending on the adaptability of the Russian sturgeon to the different environmental conditions which depend principally on the anatomy and physiology of the species Acipenser gueldenstaedtii. [ABSTRACT FROM AUTHOR]

In this study, the pathology of adult sturgeon reared in polyculture with different cyprinid species was investigated over a period of 60 days in the L.E.C.A.P. Brateș, Galați. Parasitic diseases were detected by microscopic examination and infectious diseases by clinical examination and history. Parasitosis intensity and disease prevalence assessment were associated with fish health status and water physicochemical parameters. The results suggest that the poor conservation status of some sturgeon and their feeding habits compared to cyprinids may be the cause of susceptibility to infectious diseases. Tegmental and gill parasitoses affected cyprinids more severely, while they affected sturgeons less severely, resulting in a decrease in their ectoparasitic diseases. Wild fish accidentally introduced into the pond showed increased resistance to infectious and parasitic diseases. Rearing sturgeon in polyculture with cyprinids resulted in a decrease in parasitic diseases in acipenserids. [ABSTRACT FROM AUTHOR]

This study aims to contribute to the identification of the ichthyofauna structure for the most important fish species in the Danube River, sector km 1047-1071 by quantifying the data obtained during 2021 through scientific fishing, compared to the studies carried out in 2020. The purpose of this work is also to analyze the influence of environmental factors on catches and the structure of the ichthyofauna. Compared to 2020, the appearance of the species Hypophthalmichthys molitrix (Valenciennes, 1844) in catches and changes in the ratios between catches per species and fishing seasons can be noted. Both temperature and water level showed variations in correlation with total catches. Water levels and flows show a direct correlation with both the number of specimens caught and the catches. [ABSTRACT FROM AUTHOR]

The importance of feeding live food in the first stages of fish life is crucial, because the organism is not fully developed, the accessory glands and the enzymatic equipment of the digestive tract are also insufficiently developed. Natural food brings a supply of vitamins, enzymes, and hormones with a major role in the process of digestion and absorption of the food, very important in the ontogenetic development and in increasing the immunity of fish in the larval and postlarval stages. Internationally, over the years, numerous studies have been carried out on the feeding of fish with Artemia, but the present study aims to optimize the process of feeding Artemia nauplii to freshwater fish reared in a recirculating system. This brine shrimp can survive a limited amount of time in fresh water, after which it rapidly decomposes and, due to its high protein content, becomes a water pollutant for the recirculating system. From the point of view of the costs for cyst decapsulating and the energy costs for hatching, they are too costly to afford feeding "ad libitum" with nauplii the fish larvae. The use of the minimum amount of live Artemia nauplii depends on the resistance of the nauplii in fresh water, expressed in a maximum time interval of 3.5 hours, after which vital activity and very low survival are recorded. The optimal Artemia nauplii feeding requirement of starry sturgeon with an average weight of 0.26±0.15 g and an average length of 3.78±0.8 cm is about 2.26% B.W. representing a maximum of 4.5 g wet mass of nauplii administered per 1,000 of larvae daily. [ABSTRACT FROM AUTHOR]