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The Lebranche mullet Mugil liza is a marine fish of great importance for artisanal and industrial fishing, as well as aquaculture. The use of live feeds during the larviculture phase of marine fish is a significant component of production costs. The present study evaluated the effects of the feeding transition on different larval stages of M. liza, from the combined supply of live feed (Brachionus rotundiformis + Artemia franciscana) and live + inert feed (Artemia franciscana + inert diet) until the weaning phase to only the inert diet. A total of 3240 M. liza larvae (weight 0.0133 ± 0.0062 g and length 0.793 ± 0.160 cm) were distributed among the 12 experimental units (n = 270), resulting in four groups with three replicates each. Treatment groups consisted of feed transition with A. franciscana (enriched metanauplii) to commercial inert feed starting weaning at four different larval ages: 28, 31, 34, and 37 days post hatching. Zootechnical performance indexes and intestinal histomorphometry were evaluated. Mortality, condition factor, and length variation coefficient did not show significant differences between treatments. Final weight, final length, weight gain, and length gain were significantly greater in larvae that started weaning at 31, 34, and 37 days post hatching. Weight coefficient of variation was significantly higher in larvae that started weaning at 28 days (67.51 ± 11.70) compared to 37 days (34.40 ± 7.30). In intestinal histology, villi height (180.3 ± 4.4) was significantly higher in larvae that started weaning at 37 days post hatching. Considering the evidence found in the present study, it is recommended to start weaning M. liza on the 31st day post‐hatching, using a 2‐day co‐feeding protocol (31st and 32nd days). From the 33rd day after hatching, M. liza larvae can receive only commercial feed. [ABSTRACT FROM AUTHOR]

Egypt, one of the world's biggest producers of cultured tilapia, is facing significant challenges in using drainage water for aquaculture due to the lack in freshwater. The current study was conducted to evaluate the effects of drainage water treatment on the growth and flesh quality of the Nile tilapia (Oreochromis niloticus), raised on five distinct fish farms in the El-Fayoum Governorate and irrigated with various drainage water sources. Fish growth characteristics, flesh quality, irrigation resources, drainage canals, and water quality of the investigated fish farms were all investigated. The Dayer El-Berka fish farm had the highest values of pH, total hardness, total alkalinity, salinity, and total ammonia, demonstrating the negative effects of the untreated drainage water on aquaculture water quality. All farms, with the exception of Dayer El-Berka and El-Bats fish farm (earthen pond), which showed a high lead content, had copper concentrations below detection limits. Wadi Al-Raian fish farm was recorded with higher cadmium concentrations. The El-Bats fish farm (concrete pond), which is watered with El-Bats drain's treated drainage water, showed the lowest levels of heavy metals. The maximum growth performance was found in the Nile tilapia raised on Wadi Al-Raian and Al-Wadi fish farms, whereas the lowest growth performance was found in Dayer El-Berka fish farms, according to productivity metrics. The current study's findings indicate that fish raised on farms that use treated drainage water for irrigation have great growth rates, superior meat quality, and safe flesh for human consumption. [ABSTRACT FROM AUTHOR]

The Nile tilapia (Oreochromis niloticus) and the African sharptooth catfish (Clarias gariepinus) are the most widely cultivated fish species in Egypt. The production cycle runs from spring to autumn, during which water temperatures are conducive to fish growth and the propagation of leeches, which transmit fish hemoflagellates (Trypanosoma spp.). A total of 710 Nile tilapia and 385 catfish were randomly collected from three different sites--two private farms and Burullus Lake--throughout the year. Fish blood samples were examined for Trypanosoma infection. Regardless of fish species or collection site, the highest infection rate of T. mukasai was observed during summer. The catfish samples showed a higher infection rate than the Nile tilapia, and fish farms had higher infection rates compared to Burullus Lake. A positive correlation was found between Trypanosoma infection and water temperature, nitrogenous compounds (unionized ammonia, nitrite, and nitrate), total bacterial count (TBC), and total coliform count (TCC). Based on these findings, Trypanosoma infection can be expected during the production cycle (spring to autumn), and it is recommended to maintain optimal water parameters to prevent conditions favorable to infectious agents. [ABSTRACT FROM AUTHOR]

Budikdamber innovation represents a technological advancement that combines vegetable cultivation with fish farming in a single system. This initiative is aimed at enhancing food security while providing an alternative source of income for communities. The objective of this study was to assess the sustainability of the catfish budikdamber business. A purposive sampling technique was employed for data collection, and the analysis utilized the sustainable livelihood approach (SLA) with multi-dimensional scaling (MDS). The SLA measured five types of capital: human, natural, financial, physical, and social, using specific indicators. The results indicated that physical capital contributed the most to the sustainability of the business, with a score of 87.49. Conversely, human capital was the lowest, scoring 65.28, signaling a need for improvement in human resource capabilities, particularly in cultivation technology, to ensure long-term sustainability. The overall multimodal average score of 78.41 classified the business as sustainable, with robust support from all five capitals--natural, financial, physical, human, and social. This support helps create economic opportunities for the community, underscoring the potential of the catfish budikdamber business. [ABSTRACT FROM AUTHOR]

The success of the biofloc system is contingent on its management. Therefore, this study seeked to assess the effects of intermittent fasting at different feeding rates on the efficacy of the biofloc system in terms of water quality, floc composition, growth performance, muscular chemical composition, and histomorphometry changes in the Nile tilapia muscles in comparison to the traditional system. A total of six hundred Nile tilapia fingerlings (with an average initial body weight of 54.19±1.32g) were divided into five treatments: T0 (the control) consisted of fish reared in the traditional system and fed at a rate of 4% of their body weight (BW). While, in treatments T1 and T2, fish received a feeding rate of 3% of their body weight, with T1 being subjected to continuous feeding and T2 experiencing intermittent fasting (alternating between a feeding day and a fasting day). Likewise, T3 and T4 fish were fed at a rate of 4% of their BW and were exposed to continuous feeding and intermittent fasting, respectively. The average quantity of floc, total bacteria in the floc, total phytoplankton, and total zooplankton increased with increasing feeding rates but decreased when subjected to intermittent fasting. Fish in the biofloc-based treatments exhibited superior growth performance and feed efficiency parameters when compared to those reared in the traditional system. Among the treatments, fish in T3 demonstrated the highest levels of moisture, fat, and energy content while displaying the lowest levels of protein and ash contents among other treatments. Fish in treatment T2 exhibited the lowest values of large and mean diameters and the highest values of muscular bundle intensity in comparison to the other treatments. Finally, these findings support the efficacy of intermittent fasting as a viable approach to biofloc system management, as it results in a noteworthy decrease in aquafeed expenses and overall fish production. [ABSTRACT FROM AUTHOR]

The length-weight relationship and growth performance of Sparus aurata and Dicentrarchus labrax were calculated at the El Mokretar Aqua fish farm in the Bay of Souahlia on the Algerian coast. During harvest, fish samples were collected from the El Mokretar Aqua fish farm in floating cages C8 and C3. Growth parameters were assessed at the start and end of breeding. The simple fisheries stock Aassessment methods (FSA) package estimated the length-weight relationship as LogWt= -1.18+2.08logLt for D.labrax and Log Wt= - 6.17+3.62logLt for S. aurata. These relationships indicate that the European seabass has a negative allometric growth, while the gilthead seabream has a positive allometric growth. During the rearing period, the zootechnical performance of the gilthead seabream and European seabass indicated favorable growth. Weight gain, specific growth rate, Fulton's condition factor, thermal-unit growth coefficient and feed conversion ratio showed a significant difference. These indicators are useful for planning and managing fish farms rearing these selected species. [ABSTRACT FROM AUTHOR]

Enterococcus faecium, a member of the Enterococcus genus, has emerged as a significant concern in aquaculture due to its potential pathogenicity and antibiotic resistance. This study aimed to investigate the molecular diagnosis and characterization of six different Enterococcus species isolated from the gastrointestinal tracts of the common carp (Cyprinus carpio) and tilapia (Oreochromis niloticus) and to evaluate their genetic diversity, antibiotic resistance profiles, and potential virulence factors. Among the isolates, 65.3% of the common carp and 60.8% of the tilapia were identified as E. faecium. All six species demonstrated the ability to metabolize various carbohydrates, indicating a broad metabolic capacity. Some species showed variability in their utilization of specific carbohydrates. For example, E. faecium and E. faecalis uniquely fermented adonitol, while E. avium and E. hirae were the only ones capable of fermenting D-arabitol. Additionally, Voges-Proskauer positivity was exclusively observed in E. faecalis. In terms of growth conditions, all species thrived at both 4°C and 45°C, except for E. faecalis, which failed to grow at 10°C. E. faecium and E. faecalis grew well at pH 9.6. Hemolysis tests revealed differences among the species: E. faecalis displayed beta-hemolysis, while E. gallinarum exhibited alpha-hemolysis. Motility was observed only in E. gallinarum, and esculin hydrolysis was exclusive to E. faecalis. Environmental adaptability varied among the species. E. avium showed limited growth in 6.5% NaCl, and some species exhibited little to no growth in 0.1% methylene blue milk. E. faecalis and E. faecium demonstrated survival at 60°C for 15 minutes, with E. faecium showing limited survival at 30 minutes, distinguishing them from the other species. The strains isolated from Cyprinus carpio and Oreochromis niloticus collected from local fish farms in Basrah City were confirmed as E. faecium through 16S rRNA gene sequencing. A PCR study using specific primers identified all isolates as E. faecalis. [ABSTRACT FROM AUTHOR]

The study investigated the effectiveness of three extruded feeds in the feed conversion index for the rainbow trout (Oncorhynchus mykiss Walbaum, 1792) reared at the Ain Aghbal fish farming station in Morocco. While the biochemical composition (moisture, protein, lipid, and carbohydrate percentages) and energy content (digestible and raw) of feeds A, B, and C are known, these factors alone are insufficient for selecting the optimal feed based on conversion index. The test was conducted over 222 days in tanks supplied with water from Oum Er-Rbia, flowing at 11.04m³/ h, with a water change every half an hour. Initial rearing conditions included a density of 1.58kg/ m³ and a volume-to-flow ratio of 1.05m³/ h. Fish were fed two to three times daily, depending on their growth stage. Results indicate that extruded feed B significantly improved the rainbow trout growth and achieved a conversion index not exceeding 0.9 for the trout weighing 1043g. [ABSTRACT FROM AUTHOR]

In recent years, biofloc technology has grown rapidly for various reasons, including improved water quality, cost-effectiveness, sustainability, and environmental friendliness. Therefore, the purpose of this study was to evaluate the impact of fish culture systems (a traditional system (TRS) and biofloc system (BFS)) on growth, hematological parameters, serum biochemical markers, and flesh quality of O. niloticus reared in different stocking densities (SDs). A total of 900 on-grown O. niloticus, weighing 53.17±3.32g, as initial body weight, were randomly distributed into continuously aerated tanks in two different culture systems (BFS and TRS) and stocked at densities of 50 and 100 fish/m3 for 60 days. As the SD increased, all growth performance and feed efficiency indices decreased significantly. Fish reared in the BFS showed superior growth performance and feed conversion ratio (FCR) compared to the TRS group. Fish stocked in the BFS at a density of 100 fish/m3 showed much better growth performance than TRS. Hematological indicators were enhanced in fish cultured in the BFS, especially at higher SD. Conversely, fish reared in the TRS displayed significant increases in levels of serum cortisol, glucose, total cholesterol, and triglycerides than fish reared in the BFS. Fish stocked at SD of 100 fish/m³ and reared in the BFS exhibited a significant decrease in cortisol levels and improvements in flesh quality, as indicated by decreased drip loss and frozen leakage rate compared to those in the TRS. Overall, the findings indicate the BFS's ability to mitigate the adverse effects of increasing SD on fish, emphasizing its potential as a promising technology for enhancing fish productivity and obtaining a healthy product. [ABSTRACT FROM AUTHOR]

Background: A field experiment was conducted during the rice fallow season of 2023 and 2024 (January to March) at Tamil Nadu Rice Research Institute (TRRI), Aduthurai, Tamil Nadu to study the residual effect of rice-fish-based organic nutrient management practices adopted in rice on succeeding blackgram grown as rice fallow. Methods: The experiment was carried out using randomized block design (RBD) with eleven treatments viz., T1- No Green manure- Rice crop alone (RDF), T2- Green manure- Rice crop alone (PSB+KSB+ZSB), T3- T2+Nanourea, T4-Green manure- Rice crop (PSB+KSB+ZSB) + Fish, T5- T4+ Nano urea,T6- Green manure- Rice crop (PSB+KSB+ZSB) + Fish + Azolla, T7-T6 + Nano urea, T8- Green manure-Rice crop (PSB+KSB+ZSB) + Fish + Duck, T9- T8+Nano urea, T10- Green manure- Rice crop (PSB+KSB+ZSB)+ Fish + Azolla + Duck, T11- T10+Nano urea. The treatments were replicated thrice. The blackgram variety ADT 6 was used as a test crop. Result: The results revealed that among the different organic nutrient management approaches followed in the rice-fish based farming system, the residual effect of Green manure- Rice (solubilizing bacteria such as PSB, KSB and ZSB) + Fish + Azolla + Duck (T10) resulted in higher plant height, DMP, LAI and SPAD value in blackgram. Similarly, the highest root length (19.43 cm), root dry weight (1.10 g), root volume (10.68 g/cc), nodule plant-1 at 20 DAS (13.82) and nodule plant-1 at 40 DAS (22.97) were also obtained with the same treatment. By virtue of higher growth and yield parameters, more number of pods plant-1 (26.88) and seeds pod-1 (7.73), grain yield (789 kg ha-1) and halum yield (2136 kg ha-1) of blackgram were obtained in the residual treatment of the residual effect of Green manure- Rice (solubilizing bacteria such as PSB, KSB and ZSB) + Fish + Azolla + Duck (T10). The available soil nutrients at 20 DAS of blackgram were higher in Green manure- Rice (solubilizing bacteria such as PSB, KSB and ZSB) + Fish + Azolla + Duck (T10). Due to higher blackgram yield, the same treatment achieved higher gross return (Rs.41561 ha-1), net return (Rs.30156 ha-1) and BCR (3.64). The study also indicated that the trench (300 m³) dug in rice fields for fish rearing provided sufficient moisture for rice fallow blackgram and thereby evaded the terminal stress. [ABSTRACT FROM AUTHOR]

The polychaeta Neanthes japonica is a common by-product in mariculture ponds. It is rich in essential nutrients, but has not been well-explored. Therefore, this 56-day experiment investigated the effects of substituting N. japonica meal for dietary fishmeal on juvenile tiger puffer (15.49 ± 0.02 g, n = 450 fish). The control diet (CON) contained 40% fishmeal. Freeze-dried N. japonica meal (FNM) was supplemented into CON at the levels of 3% (FNM3), 6% (FNM6), and 9% (FNM9), replacing fishmeal. The fifth diet contained 6% oven-dried N. japonica meal (ONM6), replacing fishmeal. The results indicated that no significant difference was observed in growth, feed efficiency, and somatic index among all the treatment groups. The feed intake of the FNM6 group was significantly higher compared to CON. No significant difference was detected in fish proximate composition, as well as the fatty acid composition, amino acid composition, and muscle texture. The supplementation of N. japonica meal decreased the activities of intestinal lipase and α-amylase. The addition of freeze-dried N. japonica meal significantly up-regulated the expression of the intestinal amino-glycine transporter pat1. It was concluded that adding 9% N. japonica meal to the feed had no significant effect on the growth performance and body composition of juvenile tiger puffer. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of supplementing the diet of juvenile Nile tilapia (Oreochromis niloticus), which weighs approximately 20 g, with a blend of monoglycerides (glycerides linked to a fatty acid molecule) for 20 days during a pre-experimental challenge via the intraperitoneal route (IP). Growth performance, immunological parameters, intestinal microbiota, tissue damage, and resistance against the pathogens Streptococcus agalactiae serotypes Ib and III and Francisella orientalis were evaluated. The experimental design included a negative control (NC), a product control (NPC), a positive control for each pathogen (PC), and three groups treated with different doses (0.15, 0.25, and 0.5%). After the challenge, mortality was significantly lower in the groups treated and challenged with S. agalactiae. The treated groups showed better weight gain and food conversion rates. Innate immunity parameters showed no differences between treatments, and there was no good stimulation of diversity in the intestinal microbiota. However, in treated groups, there was a reduction in opportunistic bacteria that could cause secondary infections and increased the presence of beneficial bacteria in the intestinal tract. In this way, it is possible to validate the beneficial effects of monoglycerides as a nutritional additive for tilapia farms against streptoccocosis. [ABSTRACT FROM AUTHOR]

Lumpfish (Cyclopterus lumpus) are used as cleaner fish in Atlantic salmon (Salmo salar) aquaculture as one of multiple control measures against salmon lice (Lepeophtheirus salmonis). Numerous studies have documented weight as an important factor for characterising the cleaning efficacy of individual lumpfish. Hence, the efficacy of lumpfish in fish farms depends on the size at stocking and the weight development over time. Here, we aimed to quantify how weight developed over time for lumpfish deployed in salmon farming sea cages in Norway through modelling the daily growth rate. We found that the coefficient of variation for lumpfish weight increased over time, implying that the standard deviation increased more than the expected weight. The data thus showed heterogeneous growth for lumpfish in salmon farming cages, where some individuals exhibited no apparent growth, and others significant proliferation. We found that the daily growth rate was best described as bell-shaped functions of weight and temperature, consistent with a sigmoid-shaped growth curve and an optimal temperature around 10 °C. These results allow for more realistic modelling of the efficacy of lumpfish in controlling salmon lice in fish farms, as one can combine estimates of weight-dependent cleaning efficacy with weight development over time. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) fish hepatocyte cultures are promising alternative models for replicating in vivo data. Few studies have attempted to characterise the structure and function of fish 3D liver models and illustrate their applicability. This study aimed to further characterise a previously established spheroid model obtained from juvenile brown trout (Salmo trutta) primary hepatocytes under estrogenic stimulation. The spheroids were exposed for six days to environmentally relevant concentrations of 17α-ethinylestradiol—EE2 (1–100 ng/L). The mRNA levels of peroxisome (catalase—Cat and urate oxidase—Uox), lipid metabolism (acyl-CoA long chain synthetase 1—Acsl1, apolipoprotein AI—ApoAI, and fatty acid binding protein 1—Fabp1), and estrogen-related (estrogen receptor α—ERα, estrogen receptor β—ERβ, vitellogenin A—VtgA, zona pellucida glycoprotein 2.5—ZP2.5, and zona pellucida glycoprotein 3a.2—ZP3a.2) target genes were evaluated by quantitative real-time polymerase chain reaction. Immunohistochemistry was used to assess Vtg and ZP protein expressions. At the highest EE2 concentration, VtgA and ZP2.5 genes were significantly upregulated. The remaining target genes were not significantly altered by EE2. Vtg and ZP immunostaining was consistently increased in spheroids exposed to 50 and 100 ng/L of EE2, whereas lower EE2 levels resulted in a weaker signal. EE2 did not induce significant changes in the spheroids' viability and morphological parameters. This study identified EE2 effects at environmentally relevant doses in trout liver spheroids, indicating its usefulness as a proxy for in vivo impacts of xenoestrogens. [ABSTRACT FROM AUTHOR]

17α-Methyltestosterone (MT) is a widely used androgen for all-male fish production in aquaculture. However, the molecular mechanism underlying MT-induced masculinization remains unclear. In this study, we aim to identify the key gene responsible for MT-induced masculinization using the Nile tilapia (Oreochromis niloticus) amhy, dmrt1, and gsdf mutants, which exhibit male-to-female sex reversal. Nile tilapia fry from these three mutant lines were treated with 50 μg/g MT from 5 to 30 days after hatching (dah). The results showed that amhy and gsdf mutants, but not dmrt1 mutants, were masculinized by the MT treatment. Gonadal transcriptome analysis revealed that genes involved in steroidogenesis and germ cell development in MT-treated dmrt1 mutants exhibited a similar expression pattern to that of the wild type (WT) XX. In addition, the dmrt1 mutants cannot be masculinized by co-treatment with MT and the aromatase inhibitor fadrozole. The MT treatment completely blocked early steroidogenic enzyme (Star2, Cyp17a2, and Cyp19a1a) expression independent of amhy, gsdf, and dmrt1. A luciferase analysis showed that MT directly suppressed basal and Sf-1-activated cyp19a1a promoter activity through ara and arb in cultured HEK293 cells. Furthermore, MT treatment inhibited germ cell proliferation in amhy and gsdf mutants but not in dmrt1 mutants. Consistently, dmrt1 expression was induced in MT-treated WT XX, -amhy, and -gsdf mutants. Taken together, these results suggest that dmrt1 is indispensable for MT-induced masculinization in Nile tilapia and that MT functions by inhibiting early steroid synthesis and activating dmrt1 to promote testis development. [ABSTRACT FROM AUTHOR]

To investigate the effects of water flow on fish body color, the number of melanophore and gene expression in zebrafish skin were investigated under water flow culture with two different flow rates 0. 010 m/s (low flow rate) and 0. 022 m/s (high flow rate). The results showed that compared with low flow rate, the number of skin melanophore increased significantly after 3 months of culturing zebrafish under higher flow rate, especially in the caudal region of the body of the fish, the expression levels of the skin melanophore marker genes kita, mitfa and tyrp1a were significantly increased as well. Meanwhile, the relative expression level of the xanthophore marker gene csf1ra was significantly decreased, and there was no significant change in the iridophore marker gene pnp4a, indicating that the high flow rate water induced the formation of melanophore and inhibited the formation of xanthophore. The RT-qPCR results showed that the expression of melanophore formation inhibitor gene asip1 was significantly decreased in the skin of zebrafish in the high-flow group compared with that in the low-flow group; the melanocortin receptor gene mc1r and the amelanocortinogen gene pomca, which are related to melanophore formation, were not significantly changed; and the retinoid dehydrogenase genes raldh2 and raldh3, which are related to retinoic acid synthesis, were significantly downregulated; water flow stimulation upregulated the transient receptor channel protein gene trpv4 and the piezoelectric mechanosensitive channel protein gene piezo2, whereas there was no significant change in piezo1. The above results indicate that the high flow rate water flow induces melanophore formation in zebrafish, possibly as a result of reduced asip1 expression mediated by water flow stimulation through the skin mechanosensitive proteins Trpv4 and Piezo2. Asip1 regulates fat accumulation in addition to melanophore formation, and indeed zebrafish body fullness reduces significantly in the high water flow group compared with low flow rate group. GO enrichment analysiss showed differentially expressed genes was mainly enriched to entries for triglyceride catabolism, HDL particles, lipid binding, etc and differentially expressed genes was significantly enriched in the following KEGG pathways: aminoglycan and nucleotide sugar metabolism, PPAR signaling pathway, linoleic acid metabolism, and arachidonic acid metabolism, etc. RT-qPCR showed the fatty acid peroxidase 2 gene fads2, which is associated with lipid metabolism, was significantly up-regulated, and there was no significant difference in the leptin gene lep, indicating that water flow may affect fat degradation through Asip1 affecting Fads2. In conclusion, this study for the first time reported the effect of water flow on fish body color and proposed a preliminary signaling regulatory pathway, which provides a preliminary theoretical basis for understanding the effect of water flow culture on fish body color and fullness. [ABSTRACT FROM AUTHOR]

Aquaculture, commonly conceived as "fish farming," includes the culture of anininls, plants, or other species in water. Although about 70% of Earth's surfnce is covered by water, aquaculture often uses much snialler spaces such as tanks, ponds, mceways, or aquatic enclosures to grow aquatic food, fiber, mid other resources. Theologically, humans are called to "protect and serve" (Gen. 2:15), and throughout the Bible, there nre calls to good stezoardship and cultivation while allowing for fruitfulness of other creatures. Biblically, fish are seen as God-created aquatic creatures, often used as food, with implications for wise stewardship (e.g., Psalm 8). At the present, many fisheries around the world are overfished. Sustainable nqunculture should address environmental, economic, and health concerns, and it could help reduce the stress on natural fisheries. As the fastest-growing protein sector, aquaculture now produces more seafood than the wild / mrvest of all the world 's oceans (now approximately 120 niillion metric tons per year). This promising and expanding field (approximately 6-8% growth per year over the last 50 years) includes extremely efficient converters of protein, micro- and nincro-algae (seaweeds) that con absorb unwanted wastes and clean the water, and filter feeders such as oysters and clams that Clear the water of algne and other particles, simultaneously contributing various eco-system services and habitat. Ongoing problems include pathogenic and related disease issues. environmental pollution in sulface waters, food st#ty, increasing automation utilization, potential genetic concerns, and the relatively recent start of modern aqua-culture (most nqunculture growth has occurred since 1970). This article addresses each of these hurdles, identifies areas of theological and ethical concern, and clarifies matters of interest to Christians and others, suggesting possible ways forzoard in this fast-growing but cliallenging field. [ABSTRACT FROM AUTHOR]

Aquaculture, the world's fastest-growing food production sector, is critical for addressing food security concerns because of its potential to deliver high-quality, nutrient-rich supplies by 2050. This review assesses the effectiveness of CRISPR/Cas9 genome editing technology in enhancing desirable traits in fish species, including growth rates, muscle quality, disease resistance, pigmentation, and more. It also focuses on the potential effectiveness of the technology in allowing precise and targeted modifications of fish DNA to improve desirable characteristics. Many studies have reported successful applications of CRISPR/Cas9, such as knocking out reproductive genes to control reproduction and sex determination, enhancing feed conversion efficiency, and reducing off-target effects. Additionally, this technology has contributed to environmental sustainability by reducing nitrogen-rich waste and improving the nutritional composition of fish. However, the acceptance of CRISPR/Cas9 modified fish by the public and consumers is hindered by concerns regarding public perception, potential ecological impacts, and regulatory frameworks. To gain public approval and consumer confidence, clear communication about the editing process, as well as data on the safety and environmental considerations of genetically modified fish, are essential. This review paper discusses these challenges, provides possible solutions, and recommends future research on the integration of CRISPR/Cas9 into sustainable aquaculture practices, focusing on the responsible management of genetically modified fish to enable the creation of growth and disease-resistant strains. In conclusion, this review highlights the transformative potential of CRISPR/Cas9 technology in improving fish traits, while also considering the challenges and ethical considerations associated with sustainable and responsible practices in aquaculture. [ABSTRACT FROM AUTHOR]

Simple Summary: Aquaculture is presented as a viable solution to overfishing and the growing demand for marine products. This study investigates the rearing of rainbow trout (Oncorhynchus mykiss) in a recirculating system at 3000 m above sea level, in Copaquilla, northern Chile. A total of 5000 juvenile trout were transported from the Rio Blanco fish farm over 2100 km. For 20 months, growth parameters were evaluated, including specific growth rate, weight gain, feed conversion, survival, and Fulton's condition factor. The results indicated normal growth and good quality, confirming the feasibility of trout aquaculture at a high altitude. This suggests new opportunities for aquaculture in the Andean region of northern Chile. Given the overexploitation of fisheries and the growing consumption of sea products, aquaculture is emerging as an alternative to meet the demand for protein at regional, national, and global levels. In northern Chile, the foothills of the Andes offer an opportunity for sustainable economic diversification. In this study, results of a rainbow trout (Oncorhynchus mykiss) culture in a recirculation system are presented, analyzing its growth and performance under altitude conditions. The research was carried out in Copaquilla, a small area in the foothills of northern Chile, 3000 m above sea level. Five thousand 15 g juvenile trout were acquired and transported by land from the Rio Blanco fish farm, successfully traveling more than 2100 km. During the 20-month-long culture, several growth parameters were evaluated, including specific growth rate, percentage of weight growth, feed conversion factor, survival, and Fulton's condition factor. All these parameters were within the normal growth range for trout, evidencing good-quality growth of the organisms. The results offer evidence that rainbow trout farming at 3000 m above sea level is viable and presents a viable performance, opening new opportunities for aquaculture in northern Chile. [ABSTRACT FROM AUTHOR]

Simple Summary: The Internet of Things (IoT) can improve small-scale aquaponics, a sustainable farming method that combines fish farming with plant growing in water without soil, by making the process more efficient and profitable by optimizing resource use, closely monitoring water quality, and ensuring the best conditions for both fish and plants to thrive. Aquaponics is beneficial for the environment and can help ensure a steady food supply but presents challenges for small-scale farmers due to a lack of expertise in water chemistry and system upkeep, as well as high operational costs. Identified challenges in aquaponics operation include high water and energy costs, maintaining the right balance of fish and plants, and the risk of mosquitoes breeding in the water. This systematic review offers a comprehensive guide to setting up and maintaining an aquaponics system, including choosing the right fish and plants, designing the system, monitoring water quality, and feeding the fish. The importance of knowledge sharing among farmers is also highlighted to improve aquaponics practices. The integration of IoT into these systems can reduce the need for manual work and improve the availability of information related to system control, which could facilitate further adoption and optimization of aquaponics farming practices. Aquaponics combines aquaculture and hydroponics to offer a sustainable approach to agriculture, addressing food security issues with minimal environmental harm. However, small-scale practitioners face challenges due to a lack of professional knowledge in water chemistry and system maintenance. Economic hurdles, such as operational costs and energy-intensive components, hinder the viability of small-scale aquaponics. Selecting suitable fish and plant species, along with appropriate stocking densities, is crucial. Media Bed (MB), Deep Water Culture (DWC), and the Nutrient Film Technique (NFT) are commonly used hydroponic techniques. This study outlines optimal conditions, including water quality, temperature, pH, and nutrient concentrations, essential for symbiotic fish and plant cultivation. Integrating IoT technology enhances efficiency and profitability by optimizing resource utilization, monitoring water quality, and ensuring optimal growth conditions. Knowledge sharing among practitioners fosters innovation and sustainability through collaborative learning and best practices exchange. Establishing a community for knowledge sharing is vital for continuous improvement, advancing small-scale aquaponics towards a more efficient and sustainable future. [ABSTRACT FROM AUTHOR]

The practice of hybridization is carried out globally in fish farms. Here, we present the first record of the parasitic fauna of hybrids among genus Colossoma and Piaractus in natural environments. We identified a total of 48 hybrids, nine F1 hybrids (nuclear DNA from both species present in the cross) and 38 advanced hybrids (nuclear DNA from one species), both from crosses between Piaractus brachypomus and Piaractus mesopotamicus, and one F1 "tambacu" corresponding to cross between Colossoma macropomum and Piaractus mesopotamicus. This is the first record of Anacanthorus penilabiatus, Anacanthorus toledoensis, Mymarothecium viatorum, Mymarothecium ianwhittington, Haementeria sp., Dadaytrema oxycephala, Rondonia rondoni, and Echinorhynchus gomesi parasitizing hybrids collected in a natural environment. With this, we expand knowledge about the diversity of fish and parasites in the upper Paraná River and warn about the risk that fish escapes can cause in the basin. [ABSTRACT FROM AUTHOR]

In recent years, the environmental pollution caused by microplastics (MPs) has attracted extensive attention. Numerous studies have shown that MPs could cause liver damage in aquatic animals. However, there is a limited range of technical approaches available to mitigate and minimize the detrimental impact of MPs on both wild fish populations and aquaculture operations. Thus, this study aimed to investigate the impact of dietary chitosan supplementation on the prevention and treatment of liver damage induced by exposure to polystyrene microplastics (PS-MPs) in Nile tilapia (Oreochromisniloticus). The results indicated that after two weeks of exposure, the liver of tilapia showed oxidative stress, inflammatory response and fibrosis. Meanwhile, after the chitosan addition, the oxidative stress, inflammatory response and fibrosis of tilapia liver were reversed, the pyroptosis and ferroptosis in tilapia liver were inhibited, the combination of mitochondria with PS-MPs in tilapia liver cells was inhibited, and the mitochondrial damage was reversed. In summary, the study confirmed the potential prophylaxis and treatment effect of dietary chitosan supplementation on PS-MPs exposure-induced liver damage in tilapia, and provided basic data for further studies on prophylaxis and treatment of the toxic effects of MPs. This study also presented efficacious strategies for alleviating the deleterious impacts of MPs on fish farming, thereby fostering sustainable and eco-friendly approaches in aquaculture. [ABSTRACT FROM AUTHOR]

A self-exchange aquaculture vessel stands as an environmentally sustainable solution for fish farming, capitalising on seawater utilization and minimising the risk of fish escapes through the implementation of perforated culture tanks. This research aims to lay the groundwork for the conceptual design, modelling, and simulation analysis of such vessels, focusing on how near-bottom perforation placement affects flow field characteristics within the culture tank. This paper presents a computational study using Computational Fluid Dynamics (CFD) to analyse self-exchange aquaculture vessels under both head and beam current conditions. The solution of conservation equations governing tank hydrodynamics is achieved using an implicit unsteady second-order Eulerian (finite volume) technique on optimised trimmed meshes. Experimental and predicted values for the vessel model's total resistance were evaluated using uncertainty analysis, validating the numerical model. It was found that proper positioning of perforations near the bottom significantly enhances the synergistic effect of fluid within the culture tank and the mixing characteristics of the flow field. To enhance water circulation, it is recommended to install two or more rows of perforations on the sides of self-exchange aquaculture vessels. The coordination between perforation placement and vessel structure should be considered to determine the optimal layout. By offering valuable insights into the effects of perforation placement, this study contributes to the development of more efficient and environmentally friendly aquaculture practices. • Hydrodynamics of a tank on the self-exchange aquaculture vessel studied by numerical methods. • The jet-like effect in the perforated culture tank was explored. • The influence mechanism of perforation placement on tank hydrodynamics was revealed. • Well-placed perforations boost fluid linkage inside and outside the tank. [ABSTRACT FROM AUTHOR]

Fingerling counting is a basic operation in fish farming and provides an important guideline for many aspects of aquaculture. However, most of the current counting methods are inefficient or computationally cumbersome. This study proposed a high-speed, non-intrusive fingerling counting method based on multiple detectors and a motion prediction model, which achieved high-accuracy counting under the condition of low-frame rate. Firstly, to effectively detect and locate the adherent fingerlings, the detector was accomplished by combining the mixture of Gaussian-based (MOG) segmentation algorithm and the local extremum-based blob detection algorithm. Secondly, three different functions were used to construct a motion prediction model to predict the approximate probability of the fingerlings at each position in the previous frame. Thirdly, the cost matrix was constructed with probability as the feature to associate the fingerlings in the consecutive frames, and the newly appeared fingerlings were counted in real-time, realising the continuous fingerling counting with high precision. Through testing and analysis on 52 collected datasets under low-frame-rate (10 fps) acquisition conditions using largemouth bass (Micropterus salmoides , 3–5 cm) and crucian carp (Carassius auratus , 2–6 cm), results indicated that the best motion prediction model with segmentation function reached over 99% average counting accuracy for both species, with a standard deviation of accuracy less than 0.7%. This method provides a low-cost, high-speed, and stable application solution for computer vision-based fingerling counting. • Combined Mixture of Gaussian segmentation and blob detection for fingerling counting. • Integration of a motion prediction model achieved over 99% average counting accuracy. • Open access to a dataset containing annotation files for fingerlings counting. [ABSTRACT FROM AUTHOR]

Grass carp was an important economic fish for freshwater aquaculture. The exploring and utilization of high-quality grass carp germplasm resources were important for ensuring a domestic supply of high-quality aquatic protein. However, natural grass carp populations in China were facing severe threats because of the effects of frequent human activities, water environment damage, overfishing, etc. Against this background, high-quality grass carp germplasm resources were the foundation for the healthy and sustainable development of the grass carp aquaculture industry, so systematic collection, preservation, identification, evaluation, protection, and utilization of them carry great strategic importance. This paper summarizes major research results of grass carp in morphology, cytogenetics, molecular population genetics, etc. It not only introduced genetic improvement techniques such as gynogenesis, hybrid breeding, and polyploid breeding, but also discussed the existing research on the protection measures of grass carp germplasm resources. On this basis, the paper proposed new methods to improve the protection of grass carp germplasm and create improved varieties, which could provide high-quality resources for the sustainable development of the grass carp industry. [ABSTRACT FROM AUTHOR]

Inland waters have an important role in increasing fishermen's income, satisfying community nutritional needs, providing food security for the community, functioning as habitats for aquatic organisms, and maintaining environmental balance. The gap in fish resource management in Inland Water is that many problems in Inland Water have not been revealed and are not well documented. For this reason, it is necessary to collect references to review the problems and challenges of fish resource management in Inland Waters, as well as provide solutions so that Inland Water Fisheries can be sustainable. Inland water fisheries' problems in Indonesia are sedimentation, pollution, habitat destruction, lack of fishways, and overfishing. To reduce sedimentation, deforested land on the hillsides must be replanted. Green belts on the banks of reservoirs should not be used for agriculture and settlements, and must have a good master plan for land use, and sediment dredging should be carried out regularly. To tackle pollution from fish farming activities in inland waters, fish farming in reservoirs/ lakes must not pollute the waters, and the amount must match the carrying capacity. To deal with pollution from industry, waste must be treated first before being discharged into water. Dams in rivers must be equipped with fishways so that fish can migrate. To overcome overexploitation, the number and types of large fishing gear, such as liftnets, filtering device, active seine, and active barrier, along with fishing using poisons, chemicals, or electricity, must be monitored and punished. Based on the findings in the review that explain the problem and how to overcome it, fish resource management has a chance of success if it is good in its management. [ABSTRACT FROM AUTHOR]

Fish meal (FM) replacement is essential for the sustainable expansion of aquaculture. This study focussed on the feasibility of replacing FM with a single‐cell protein (SCP) derived from methanotrophic bacteria (Methylococcus capsulatus, Bath) in barramundi fry (Lates calcarifer). Three isonitrogenous and isoenergetic diets were formulated with 0%, 6.4% and 12.9% inclusion of the SCP, replacing FM by 0%, 25% and 50%. Barramundi fry (initial body weight 2.5 ± 0.1 g) were fed experimental diets for 21 days to assess growth performance, gut microbiome composition and gut histopathology. Our findings revealed that both levels of SCP inclusion induced detrimental effects in barramundi fry, including impaired growth and reduced survival compared with the control group (66.7% and 71.7% survival in diets replacing FM with SCP by 25% and 50%, respectively; p <.05). Both dietary treatments presented mild necrotizing enteritis with subepithelial oedema and accumulation of PAS positive, diastase resistant droplets within hepatocytes (ceroid hepatopathy) and pancreatic atrophy. Microbiome analysis revealed a marked shift in the gut microbial community with the expansion of potential opportunistic bacteria in the genus Aeromonas. Reduced overall performance in the highest inclusion level (50% SCP) was primarily associated with reduced feed intake, likely related to palatability issues, albeit pathological changes observed in gut and liver may also play a role. Our study highlights the importance of meticulous optimization of SCP inclusion levels in aquafeed formulations, and the need for species and life‐stage specific assessments to ensure the health and welfare of fish in sustainable aquaculture practices. [ABSTRACT FROM AUTHOR]

The introduced salmonid ectoparasite Gyrodactylus salaris has been detected on Atlantic salmon in 53 Norwegian rivers and in 39 Norwegian fish farms. In affected rivers, the mortality of Atlantic salmon juveniles is very high, estimated to a mean of 86%. G. salaris has been considered one of the biggest threats to wild Norwegian Atlantic salmon stocks. With various measures, the authorities have reduced the potential for further spread of the parasite to new rivers and fish farms, and G. salaris has been eradicated from 43 rivers and all fish farms. Furthermore, the eradication process is almost completed in five affected rivers located at the Norwegian west coast, while preparations for the eradication in the remaining five rivers in the southeastern part of Norway have begun. The goal of Norwegian management is to eradicate the introduced pathogenic G. salaris strains from all occurrences in Norway. In fish farms, the parasite has been removed by mandatory slaughter of infected fish. In rivers, G. salaris has mostly been removed by killing all the fish hosts with rotenone. The indigenous genetic Atlantic salmon stocks are re‐established after eradication of the parasite. New methods are developed using chemicals that kill the parasite without killing fish in the rivers. Norwegian authorities have so far used more than NOK 1.5 billion on research, monitoring and combating G. salaris. However, the benefits are considered many times greater than the spending. Without control measures, G. salaris would likely have spread to new Atlantic salmon rivers where the same catastrophic outcome had to be expected. The Norwegian authorities seem to meet the goal in their long‐term work to halt the spread of G. salaris and to eradicate the parasite in affected rivers. [ABSTRACT FROM AUTHOR]

The orange-spotted grouper (Epinephelus coioides) is one of the most popular fish in aquaculture due to its high economic value. However, the random occurrence of slow-growing population has led to profit loss. Therefore, transcriptomic analysis was performed to identify the molecular mechanisms involved in driving slow and fast growth, towards addressing this issue. Results show that low expression of developmental genes such as bone morphogenetic protein 1 (BMP 1) and somatostatin (SST), as well as GH/IGF axis-related genes (IGF-1, IGF2, IGFBP1, IGFBP2) and its downstream signalling pathways are correlated with the metabolism and digestive-system-related pathways in slow-growing groupers. Enrichment analysis further revealed that cellular process and biological regulation, as well as several pathways including glycolysis/gluconeogenesis, linoleic acid metabolism, protein digestion and absorption, and cholesterol metabolism were differentially expressed in slow-growing groups. The findings implied that the genomic architecture of growth between the different families raised and the likely problem of inbreeding have led to significantly reduced growth. It is also suggested that better husbandry practices (optimal dietary requirement) is also vital in supporting the success of a genetic improvement programme. These findings recommend growth improvement of orange-spotted groupers via molecular monitoring and artificial selection, complemented by specific dietary feeding. [ABSTRACT FROM AUTHOR]

To optimize fish production by a better knowledge of preventive measures against fish diseases, a cross-sectional audit was carried out in Cameroon from March to April 2022 on the zootechnical factors affecting the biosecurity practice in fish farms from the Centre Region (3°55'-4°67'N; 9°46-11°52' E). A total of 50 farms were selected using the "snowball" method, face-to-face interviews of fish farmers using a semistructured questionnaire, and direct observation. The most practiced farming system was the semi-intensive production system (74%), non-integrated fish farming (100%), grow-out (66%), monoculture (54%), and the soil system (34% of farms with ponds). The compliance rate (40.98%) and adoption rate (41.00%) of biosecurity measures (BM) were intermediate. The most adopted BM were "sanitary lock" and "no exchange of materials with other farms", while the least adopted was "veterinary intervention", "dead fish incinerated" and "special outfit for visitors". The BM was significantly more observed in intensive, nursery farms and those whose culture facilities were fastanks + concrete tanks with 3 to 12 production cycles per year. A strong, positive, and significant linear relationship was established between the compliance rate (y) and BM such as the protection of farms from wild animals, quarantine of new fish, and number of production cycles per year (x). The linear regression model between y and x was y = 4.65x - 0.0417. The capacity of fish farmers should be built on biosecurity practices. [ABSTRACT FROM AUTHOR]

The land-based recirculating aquaculture system (RAS) has been widely applied to fish farming as a new eco-friendly culture model. This system consists of circular culture tanks on land integrated with water treatment and recycling systems. This study investigated the growth performance of juvenile gibel carp (Carassius gibelio) cultured at high stocking density (HSD, 0.3 kg/m3) and low stocking density (LSD, 0.15 kg/m3) conditions in RAS, and evaluated the comprehensive economic profit of RAS. The body weight, body length, weight gain rate, and condition factor of gibel carp in the LSD group were significantly higher than those in the HSD group (p < 0.05). The feed conversion ratio increased significantly in the HSD group (p < 0.05). A histological analysis revealed a significantly higher density of white muscle fibers in the LSD group (p < 0.05). Relative mRNA expression levels showed that ubiquitin–proteasome system (UPS)-related genes, ub, psma2, and mafbx, were significantly expressed in the HSD group, while the s6k1 expression was elevated in the LSD group (p < 0.05). The mRNA expression levels of keap1 and hsp70 in the dorsal muscle were significantly higher in the HSD group (p < 0.05). Throughout the rearing period, the water temperature remained consistent between the two density groups. The pH value gradually decreased and the dissolved oxygen levels in the HSD group were generally lower than in the LSD group. The nitrite nitrogen (NO2−-N) content was higher in the HSD group. Compared to the LSD group, the return on investment was significantly lower in the HSD group. In conclusion, the water quality and growth rates of juvenile gibel carp were better in the LSD group. An appropriate stocking density improved the growth performance and aquaculture economic efficiency. [ABSTRACT FROM AUTHOR]

Increasing need for food resources, State of Indonesia to strive to maximize the output of food production. Not only in agriculture but also aquaculture results are also trying to be improved. This is also supported by the increase of Indonesia’s national fish consumption rate from 50.69 Kg per capita in 2018 to 55.37 Kg per capita in 2021. Recent aquaculture research only explored topics about monitoring the cultivation environment. But there have been no studies exploring how bad the impact of weather on the process of farming. Hence, this study aims to measure the influence of weather on freshwater aquaculture pond water quality and analyze its impact on fish growth namely Oreochromis Sp., using pH sensors and dissolved oxygen (DO). Then a weather simulation was carried out based on Indonesia’s tropical climate, which majorly consists of sunny and rainy weather. The experimental results indicate the instability of the pH value during the rainy period. DO values tend to decrease at the end of periods of sunny weather. Moreover, fish growth analysis showed that there was a decrease in food conversion ratio (FCR) by 0.956, specific growth rate (SGR) by 2.13% and survival rate (SR) by 5.715% during rainy weather. [ABSTRACT FROM AUTHOR]

The ectoparasitic copepod Lernaea cyprinacea (anchor worm) has more than 100 host species among teleost fishes and affects cyprinids both in fish farms and natural waters. In addition, while L. cyprinacea infection in amphibians has been recorded in Asia, North and South America, there is no data available in the literature on their presence in Europe. In this study, we first reported L. cf. cyprinacea parasitising an anuran tadpole in Europe. Specimens of L. cf. cyprinacea were observed attached to a tadpole of the agile frog (Rana dalmatina), which was caught during fishing of crucian carp fingerlings (Carassius carassius) from a small fish pond in Hungary during the summer of 2012. The infected tadpole was collected from a rearing pond, where juvenile crucian carps were kept. The tadpole was inspected in the laboratory, and digital photos were taken. The parasites were found attached to the body-tail junction and to the leg of the tadpole (at Gosner stage 41). The parasite species was identified as L. cf. cyprinacea based on morphological traits. [ABSTRACT FROM AUTHOR]

Uganda's aquaculture sub-sector is rapidly developing, contributing up to 22% of all fish produced in the country. However, this sub-sector still faces challenges related to limited access to extension services, production inputs, post-harvest handling facilities, disease incidences, value-addition skills, and weak market linkages. Although there have been isolated interventions at different aquaculture value-chain nodes, the registered challenges continue to recur. To address prioritized issues in Uganda's aquaculture sub-sector, nine zonal aquaculture innovation platforms were established based on the country's nine agro-ecological zones. These platforms brought together different stakeholders to identify solutions to common problems in each aquaculture value-chain node. Each innovation platform consisted of fish farmers, hatchery operators, traders, extension workers, researchers, input dealers, local leaders, and financial institutions. During a series of zonal workshops, participants identified constraints on the aquaculture sub-sector in their respective zones. From the findings, there are technical knowledge gaps across the entire aquaculture value chain, mainly affecting hatchery operators, input suppliers, and farmers. Therefore, there is need for coordinated interventions to enhance access to production technologies, innovations, knowledge, and skill transfer to promote gender-centered aquaculture development. [ABSTRACT FROM AUTHOR]

Plastic pollution is a global problem affecting all ecosystems, and it represents most of the marine litter. Offshore aquaculture is a sector particularly vulnerable to this issue. To investigate this concern, the present study employed videography to monitor macroplastics at an offshore fish farm on Madeira Island (Portugal) and analysis of fish gut content to evaluate macroplastic ingestion by farmed sea bream Sparus aurata. Our analysis revealed that the majority of identified plastic debris originated from domestic use (66.66%) and fisheries/aquaculture activities (24.99%). While the number of dead fish suitable for sampling was limited (1.05% of the total mortality), macroplastic debris ingestion was identified in 5.15% of the total mortalities and reported for the first time in species in offshore farming conditions. Fish ingested fragmented plastic sheets, with the amount positively correlated with fish weight (r = 0.621, p = 0.031, n = 12). Notably, the stretched length of these fragments exceeded 50% of the standard length of most fish. Inconsistencies were observed in the number of samples collected per cage and per week. To ensure robust results, these discrepancies should be rectified in future studies. Additionally, extending the sampling period to encompass all seasons would be beneficial for a more comprehensive understanding of seasonal variations in plastic occurrence. [ABSTRACT FROM AUTHOR]

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The article discusses the need to increase food production and renewable energy generation in a sustainable manner due to the projected increase in the world population. Offshore aquaculture and renewable energy production are identified as potential solutions, offering ample space and resources. The article explores advances, opportunities, and challenges in offshore aquaculture, including modifications to infrastructure for fish farming and the cultivation of seaweed. It also discusses the development of offshore renewable energy sources, such as wind, solar, wave, and tidal currents. The integration of aquaculture and renewable energy production is highlighted as a promising approach, but challenges such as regulatory frameworks and stakeholder engagement must be addressed. [Extracted from the article]

The study describes the distribution of fish farming activities, identifies and characterizes the stakeholders involved, and assesses their level of knowledge and the techniques used for fish farming in the Territory of Mbanza-Ngungu. Furthermore, it proposes avenues to improve the sustainability and profitability of the sector. The methodology relied on a snowball approach to recruit a representative sample of 350 fish farmers. Field visits allowed for detailed data collection through a specially designed questionnaire. The data were analyzed using statistical methods (chi-square test of independence) to identify trends and challenges across the sectors of the territory of Mbanza-Ngungu. The findings revealed that fish farming activities are distributed across the territory of Mbanza-Ngungu, with a male predominance (96%) among fish farmers and a growing trend of this activity among older individuals over 40 years old (48%). Additionally, the results demonstrate that aquaculture is mainly a secondary activity for 97% of respondents, yet it could play a pivotal role in household economic diversification. The study identifies predominant practices, such as extensive farming (89%) and monoculture (92%), while highlighting gaps in pond management and fish farmers' general knowledge. Challenges are mainly related to feed access (28%), financing (27%), training (23%), and water quality monitoring (100%). The commercial orientation of production towards sales (94%) rather than self-consumption offers an opportunity to improve this sector in this territory. Finally, recommendations are made to enhance the sustainability and profitability of aquaculture in the region, including promoting integrated practices, more efficient pond management practices, and aquaculture product processing. [ABSTRACT FROM AUTHOR]

The leading cause of hospital-acquired infections worldwide includes Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. (ESKAPE) infections. These bacteria are commonly isolated from clinical settings and linked to a number of potentially fatal diseases associated with hospitals. The objective of this study was to review the prevalence of ESKAPE pathogens in Africa. We gathered and systematically reviewed the literature concerning the prevalence of ESKAPE pathogens, published in the English language from January 2014 to February 2024, from three databases (PubMed, Web of Science and ScienceDirect). Our overall results revealed that S. aureus was the most prevalent species (79.5%), followed by A. baumannii (27.6%), K. pneumoniae (24.2%), Enterobacter spp. (20%), P. aeruginosa (9.0%), and E. faecium (5.1%). Moreover, stool samples had the highest Pooled Prevalence Estimates (PPEs) of 44.0%, followed by urine, nasal, and blood samples with 37.3%, 26.9%, and 22.9%, respectively. For the diagnostic method used to identify these ESKAPE pathogens, VITEK-MS had the highest PPE of 55.2%, followed by whole genome sequencing and PCR with 37.1% and 33.2%, respectively. The highest PPE of ESKAPE pathogens was recorded in West Africa with 77.3%, followed by Central/Middle Africa and East Africa with 43.5% and 25.1%, respectively. The overall PPE of ESKAPE pathogens from humans, animals, the environment (water, soil, and surfaces) and food sources was 35.8%, 37.3%, 47.7%, and 34.2%, respectively. Despite their prevalence in nosocomial settings, studies have shown that the ESKAPE pathogens may be isolated from a range of environmental reservoirs, including soil, dumping sites, beach sand, wastewater, food, and fish farms, among others. This wide source of ESKAPE pathogens substrates indicates the need for a multidisciplinary collaborative partnership for epidemiological studies and intervention efforts by the human, veterinary, and environmental health sectors in Africa. [ABSTRACT FROM AUTHOR]

Tilapia stands out as one of the most extensively farmed and consumed fish species globally, valued for its ease of preparation and relative affordability. Although tilapia is a valuable protein source, it can also function as a vector for foodborne pathogens. This literature review reveals that tilapia could carry a variety of contamination with various foodborne pathogens, including Plesiomonas shigelloides, diarrheagenic Escherichia coli, Vibrio parahaemolyticus, Salmonella Weltevreden, Salmonella enterica, Shigella, Staphylococcus aureus, Campylobacter jejuni, Clostridium botulinum, and Listeria monocytogenes. Although guidelines from entities, such as the Global Seafood Alliance, Aquaculture Stewardship Council, and International Organization for Standardization, have been established to ensure the microbiological safety of tilapia, the unique challenges posed by pathogens in tilapia farming call for a more nuanced and targeted approach. Recognizing that contaminants could emerge at various stages of the tilapia supply chain, there is a crucial need for enhanced detection and monitoring of pathogens associated with this fish and its culturing environment. Additionally, it is essential to acknowledge the potential impact of climate change on the safety of tilapia, which may elevate the prevalence and contamination levels of pathogens in this fish. Proactive measures are essential to understand and mitigate the effects of climate change on tilapia production, ensuring the sustainability and safety of this seafood product for both present and future generations. [ABSTRACT FROM AUTHOR]

The latest advances in science, combined with the growing possibilities of modern technology, contributed to the improvement of fish feeding technology and fish farming in general. It is obvious that the expansion of the species composition of cultivated fish farming objects will continue, and the importance of feed and fish feeding technology will steadily increase. The developed recipes of starter feeds for juvenile fish and the technology of their production would make it possible to establish the production of these feeds for fish farms in Kazakhstan, as a result, the survival rate and growth rate of juvenile fish grown in industrial conditions would increase. The aim of the work was to develop recipes for starter feeds for pikeperch fry and technology for their production by extrusion, the development of these feeds to improve the efficiency of growing pikeperch in industrial conditions. According to the developed recipe, a starter feed for zander juveniles, balanced in terms of basic nutrients, was developed, a study was made of the effect of this feed on the efficiency and speed of growing zander juveniles. The dynamics of rearing juvenile pikeperch was studied when feeding the starter feed developed by the Kazakh Research Institute of Processing and Food Industry, with a feed coefficient of 1.28 and as a control foreign starter feed for trout “Aller Aqua” – 1.2. The materials of the article are of practical importance and the need for further research, they will help replenish the formulas of compound feed for the industrial cultivation of juvenile pike perch in fish farms of the Republic of Kazakhstan. [ABSTRACT FROM AUTHOR]

Purpose. Analysis of obtained data and integration of previous hydroecological data and statistical information for the preparation of scientific and biological rationale and development of the regime for rational and environmentally sustainable fishery exploitation of the Khrystoforivske Reservoir. Methodology. Hydrochemical and hydrobiological methods of sampling, laboratory and statistical processing of the material were used in the water area of the Khrystoforivske reservoir of the Bokovenka river during comprehensive studies in the summer of 2022. We studied the hydrochemical parameters of the water body, species composition, quantitative parameters of the main groups of hydrobionts, including fish forage organisms (macrophytes, phytoplankton, zooplankton, zoobenthos), the biological productivity of the reservoir was measured based on the main groups of hydrobionts. To determine the state of the main groups of hydrobionts, two samples of phytoplankton, zooplankton and zoobenthos were collected. Macrophytes were studied, water samples were taken from different parts of the water body for hydrochemical analysis. The biomass of phytoplankton was calculated based on the biomass of standard volumes of algae, the biomass of zooplankton – by multiplying the quantity of organisms by their individual weights, zoobenthos – by weighing individual groups of hydrobionts on torsion scale and recalculating and summing up. The reservoir feeding capacity was assessed by the quantitative development of zooplankton according to known classifications. Findings. The main parameters of the chemical composition and properties of the water of the Khrystoforivske reservoir, which condition the bioproductivity and fish farming performance, were determined: pH, content of dissolved gases, organic substances, biochemical demand of O2, nutrients content, as well as general mineralization and hardness, concentration of the major ions. According to the hydrochemical classification, water is bicarbonate type II and is referred to fresh water. The degree of water saturation with easily-oxidizable organic matter has decreased over the past 15 years and is within standards for aquaculture. Considering all environmental and sanitary parameters, water of the Khrystoforivske reservoir is characterized by fair or average quality, it is eupolytrophic. The water characteristics indicate that the fishery exploitation at the reservoir during previous Special Commodity Fish Farming Regimes (SCFF) (1996–2021) has produced no adverse effects on the general ecological and sanitary condition of water. Aquatic phytocoenoses of the Khrystoforivske reservoir are represented by associations of submerged and aerial-aquatic plants, with a total area of 5.2 hectares. The total production of aquatic plants is 36.245 tons. The phytoplankton of the reservoir includes 51 species of algae (six groups). In terms of quantity, small-celled Cyanoprokaryota predominated (about 70%). Diatoms, green and euglenic algae dominated in biomass. In 2022, the average biomass of phytoplankton in the Khrystoforivske reservoir was up to 1.80 g/m3, the total annual production of phytoplankton reached 201.06 tons. In total, 16 species of organisms have been identified in the zooplankton of the reservoir: Rotatoria, Cladocera and Copepoda. The average abundance of zooplankton in the reservoir was 31,390 ind./m3, and its average biomass reached 0.41 g/m3. The value of primary production of zooplankton is 123.9 kg/ha, and the total stock in the reservoir is 7.687 tons. The fish food supply in terms of zooplankters in the Khrystoforivske reservoir are low. The reservoir itself, based on the group of zooplankton, can be referred to fishery class III (the lowest class). The bottom fauna is represented by 40 taxonomic groups of invertebrates. The Chironomidae and Oligochaeta assemblies are most developed in terms of density, but molluscs dominate in biomass. There is a general trend towards a decrease in the quantitative parameters of macrozoobenthos, in particular, Mysidacea. The average biomass of soft benthos (2.17 g/m2) and the average biomass of the entire zoobenthos (33.62 g/m2) indicate that the reservoir preserves its fishery potential due to macrozoobenthos. The primary production of zoobenthos of the Khrystoforivske reservoir is 130.2 kg/ha. The total stock of zoobenthos is up to 8.072 tons. The values of the fish food supply are quite high due to zoobenthos in the reservoir, the water body in terms of benthos biomass is referred to fishery class II (medium productive reservoirs). The obtained comprehensive data on the food supply of the Khrystoforivske reservoir indicate the availability of sufficient bioproduction potential for its continuous effective fish-farming on the basis of the special commodity fish farming regime. Originality. For the first time in the last 10 years, comprehensive data on the food supply of the Khrystoforivka reservoir, which is used in special commodity fish farming regime (SCFF), have been obtained and analysed. Practical value. The results obtained are of practical importance for the development of scientific and biological rationale for fish farming in the Khrystoforivske Reservoir.

This study evaluated the effects of different feeding rates on the rearing of the curimba Prochilodus lineatus under biofloc (BFT) conditions. One hundred and sixty juvenile P. lineatus with average weights and lengths of 27.33 ± 2.07 g and 13.52 ± 0.16 cm, respectively, were randomly distributed in 16 experimental units (80 L) under BFT conditions and subjected to four feeding rates: 1.0%, 3.0%, 5.0%, and 8.0% of the fish biomass, for 60 days. During the assay, water quality variables and the proximate composition of the biofloc were monitored, as well as the productive performance and hematology of fish were evaluated. Compared to fish that received the diet at a rate of 1.0% of the biomass, the final length (14.47 ± 0.43 cm), final weight (35.55 ± 3.21 g), and gain in length (1.21 ± 0.34 cm) were significantly higher than those that received 5% of the biomass, while the fish that received 5.0% and 8.0% of the biomass, weight gain, and specific growth rate were significantly higher than those that received 1.0% of the biomass. Final biomass (296.89 ± 18.30 g) was significantly greater in fish that received the diet at a rate of 8.0% of the biomass than those that received 1.0% of the biomass (198.30 ± 49.36 g). The feed conversion rate (1.74 ± 0.26) was significantly lower in fish that received the diet at a rate of 5.0% than those that received 1.0% and 3.0% of the biomass. The protein efficiency (− 10.35 ± 5.37%) decreased significantly in fish in the 1.0% of the biomass. The survival rate of fish was significantly lower in fish from the 5.0% of the biomass (66.32 ± 14.03%) than in fish that received 3.0% of the biomass (100.00 ± 0.00%). The concentration of dissolved oxygen was significantly higher in the culture water of fish that received 1.0% and 3.0% of the biomass. The amount of sedimentable solids in the water was significantly higher in the culture water of fish at 8.0% of the biomass (242.50 ± 181.18) than in the groups of 1.0% and 3.0% of the biomass, while the hardness significantly decreased in the culture water of fish that received a diet at a rate of 5.0% of the biomass. Carbon dioxide was significantly greater in the water of the 3.0% of the biomass than in the 5.0% of the biomass. Regarding the proximal composition of the bioflocs, the dry matter significantly increased in the groups that were fed with a feeding rate of 8.0% (28.58 ± 0.01%), while the lowest contents were observed in the groups that received a feeding rate of 3.0% of the biomass. Crude protein was significantly lower in the groups that received a feeding rate of 1.0% of the biomass (28.94 ± 0.01%) than in the groups of 3.0% of the biomass. Ether extract was significantly greater in the groups of 8.0% of the biomass (1.62 ± 0.00%) than in the 3.0% of the biomass. Monocytes were significantly increased in fish that received a diet at a rate of 1.0% of the biomass compared to fish from the 5.0% and 8.0% of the biomass. Neutrophils were significantly increased in fish that received a diet at a rate of 5.0% of the biomass compared to fish in the 1.0% of the biomass. Hemoglobin was significantly decreased in fish that received a diet at a rate of 1.0% of the biomass. Hematocrit was significantly decreased in fish that received a diet at a rate of 1.0% and 8.0% of the biomass compared to fish from the 3.0% of the biomass. The results suggest that the cultivation of P. lineatus under biofloc conditions could be viable. Considering the productive performance, hematology, and water quality, a feeding rate of 5.0% of the biomass proved to be adequate for the experimental conditions adopted in the study. [ABSTRACT FROM AUTHOR]