Search Results (95)

Tilapia Lake Virus (TiLV) is well known as a highly contagious viral infection in aquaculture, particularly affecting Tilapia worldwide. Until recently, various TiLV diagnostic methods have been used for rapid and accurate diagnostic procedures that are crucial for timely disease detection and reducing losses. In this study, we developed an alternative method for investigating TiLV diagnosis using Reverse Transcriptase Recombinase Polymerase Amplification (RT-RPA) assay combined with a lateral flow dipstick (LFD). The test was generated by specific anti-FITC and anti-Biotin capture antibodies that are compatible with the TiLV-specific primers tagged with FITC and Biotin. The test was conducted by the reverse transcriptase of target TiLV RNA and RPA amplification at 39 °C for 20 min. The products were then determined by a positive band signal via LFD. The RT-RPA-LFD assay detected the plasmid of TiLV (pTiLV) with a Limit of Detection (LOD) of 3.19 copies/µL, while the RT-PCR-LFD assay detected it with an LOD of 319 copies/µL. Our findings demonstrate that RT-RPA-LFD represents a possible alternative to RT-PCR for the rapid and sensitive detection of TiLV, especially in areas with limited infrastructure. Full article

The healing process of full-thickness skin wounds in maraena whitefish (Coregonus maraena) was investigated to provide preliminary insights into the species’ tissue regeneration mechanism and dynamics following mechanical injury-simulating standard aquaculture PIT tagging procedures. A mechanical skin injury was induced on the dorsal flank of one-year-old maraena whitefish using a 15G needle, and skin regeneration was tracked for 15 days post-wounding (dpw). Expression levels of six genes involved in immune response and inflammation (IL-17D and CD-4), cellular stress response (HSP-90), and cell proliferation and tissue growth (MMP-9, p53, and TGF-β) were examined in wounded and intact skin tissues, liver, and head kidney. Histological analyses were also performed to monitor wound-healing progression. Histological examination revealed typical fish wound-healing characteristics involving re-epithelialization on the 1st day post-wounding (dpw), acute inflammation on the 3rd dpw, granulation tissue formation and intensive wound remodeling on the 8th dpw, and full tissue regeneration by the 15th dpw. Gene expression analysis revealed dynamic tissue-specific patterns: IL-17D and CD-4 were upregulated early in wounded skin, indicating rapid immune and inflammation activation, while MMP-9 and TGF-β peaked later, supporting tissue remodeling and regeneration. HSP-90 and p53 genes were highly expressed in the mid to late stage of healing, reflecting cellular stress response associated with acute inflammation and a high rate of cell proliferation in wounded skin. Significant transcriptional changes in the liver and head kidney further supported the systemic nature of the wound response and emphasized the importance of immune function in the species’ tissue-repair process. The obtained findings provide novel insights into the mechanisms and dynamics of skin healing in maraena whitefish, potentially supporting the development of improved health management strategies for this species in aquaculture. Full article

The use of solid products deriving from the pyrolysis of wastes as potential substitute of traditional binders in asphalt preparation is investigated with the final goal of reducing production costs, preserving non-renewable resources, and promoting an effective resource use as well as recovery and recycling procedures, thus implementing a regenerative circular economy approach. Char derived from the pyrolysis of agricultural and aquaculture wastes has been explored as a novel alternative additive for asphalt production. Different feedstocks were used for the preparation of biochar by pyrolysis. The produced char samples, after an in-depth chemical and structural characterization, have been implemented in the preparation of asphalt mixtures, with their potential use as a binder evaluated by performing conventional rheological tests. To evaluate the potential anti-aging effect of char as an additive, bituminous formulations containing 3 to 6 wt.% char were subjected to short-term simulated aging using the Rolling Thin-Film Oven Test (RTFOT) method. The resulting mechanical properties were then assessed. The results indicate that the all the tested char samples have limited modifying properties towards the gel-to-sol transition temperature. Among the samples, lemon peel-derived char (LP-char) showed superior antioxidant properties against bitumen oxidative aging. This study suggests that certain chemical characteristics can serve as predictive indicators of antioxidant activity in biochars produced from biomass pyrolysis. Full article

The gray triggerfish Balistes capriscus has a wide geographical distribution and is used for commercial and recreational fishing worldwide. In this study, we aimed to provide technical knowledge for developing strategies for the sustainable production of gray triggerfish in aquaculture systems by characterizing the capture procedures for broodstock acquisition and developing a protocol for species maintenance in captivity. Broodstock maintenance data were collected over six months (April to September) each year, whereas breeder data were collected over three months each year (November to January). The number of shipments, capture, and survival of B. capriscus was 100%. The animals grew on average by 9.99 ± 0.11 cm over 9 months and increased their average weight by 1.658 ± 0.1 kg, representing a specific growth rate of 0.62% and an average daily weight gain of 6.14 g/day. The species were fed by alternating the supply of fresh food (minced fish, fish fillets, shrimp, squid, minced octopus and crab), divided into two times, 9:00 a.m. and 4:00 p.m., and offered until the animals were satiated. Regarding the structures used to maintain the breeding stock, 15,000 L tanks are recommended to keep up to 30 breeding individuals. Full article

Anesthesia is commonly used in sturgeon aquaculture to reduce stress and pain during handling and procedures. This study compared the effects of clove oil (rich in eugenol) and propofol—an anesthetic widely used in human and veterinary medicine—on Persian sturgeon (Acipenser persicus) fingerlings. A total of 405 fish (6.88 ± 0.90 g) were exposed to varying concentrations of clove oil (25, 50, 75, 100 mg L⁻¹), propofol (10.0, 12.5, 25.0, 50 mg L⁻¹), or no anesthetic (control) in triplicate. Hematocrit and monocyte levels remained unchanged across treatments, but the highest doses of both anesthetics significantly reduced leukocyte percentages (p = 0.049 and p = 0.043, respectively). While serum enzymes were stable, cortisol levels increased significantly at the highest concentrations of both clove oil (38.92 ± 5.1 ng mL⁻¹; p = 0.001) and propofol (36.48 ± 3.4 ng mL⁻¹; p = 0.035), indicating secondary stress responses. Propofol at 25 mg L⁻¹ showed fast induction and recovery times and induced milder stress compared to clove oil. Overall, short-term anesthesia with both agents triggered physiological stress, but propofol at 25 mg L⁻¹ appeared more suitable for minimizing adverse effects in Persian sturgeon fingerlings. Full article

Growing evidence of pain perception in fish has raised concerns about their welfare in different contexts, including research and aquaculture, where potentially painful procedures are standard. Despite ongoing efforts to advance fish analgesia, the field remains underdeveloped, particularly regarding less invasive methods that could improve welfare, such as immersion-based analgesia. As one of the most widely used models in research, zebrafish (Danio rerio) are often at the front of these concerns. This review aimed to consolidate the current knowledge on immersion analgesics by analyzing the behavioral responses of zebrafish exposed to noxious stimuli. Some promising immersion analgesics were identified; however, further research is needed to assess their effects on additional parameters and investigate potential adverse effects. These findings underscore the importance of selecting appropriate analgesics, as their effectiveness may vary depending on the duration and severity of the stimulus. Moreover, this review highlights the critical role of consistent water quality monitoring and detailed parameter reporting, as these factors may influence analgesic efficacy and compromise fish welfare. As research advances, applying these insights beyond zebrafish to other fish species will be crucial for promoting higher welfare standards. Full article

Worker safety has been relatively overlooked in the rapidly growing aquaculture industry. To address this gap, industrial accident compensation insurance data—mainly from floating cage and seaweed farming—were analyzed to quantify accident types and frequencies, with a focus on human elements as root causes. Basic causes were selected based on IMO Resolution A/Res.884 and assessed through a worker awareness survey. Fault Tree Analysis (FTA), a Formal Safety Assessment technique, was applied to evaluate risks associated with these causes. The analysis identified organization at the farm site (23.3%), facility and equipment factors (22.8%), and people factors (21.4%) as the primary causes. Among secondary causes, personal negligence (13.2%), aging gear and poor maintenance (11.4%), and insufficient risk training (10.4%) were the most significant. Selective removal of these causes reduced the probability of human element-related accidents from 64.6% to 48.6%. While limited in scope to Korean data and self-reported surveys, the study demonstrates the value of combining quantitative data with worker perspectives. It provides foundational data for developing tailored safety strategies and institutional improvements—such as standardized procedures, multilingual education, and inclusive risk management—for sustainable safety in aquaculture. Full article

Feeding is an elementary human need from which we obtain the energy and nutrients necessary for development and survival. Health heavily depends on food, which can be a means of different microbial hazards when contaminated at any stage of the food chain, compromising food safety and consumer health. Fish are considered widely produced foods (fishing or aquaculture) and are marketed worldwide; they are also a basic element of the human diet because they are a source of proteins and lipids. On the other hand, owing to their chemical properties (neutral pH and water activity), fish are highly susceptible to contamination by saprophytic and pathogenic microorganisms related to spoilage and risk to human health. Among the contaminating microorganisms in fish are bacteria of the genus Klebsiella, which are considered important in human and animal health worldwide due to their opportunistic pathogenicity, resistance to various antimicrobials, and association with numerous infections at the community and hospital levels, where foods such as fish and other products can serve as important sources of transmission. Therefore, this document presents a bibliographic review focused on describing, in a general way, the genus Klebsiella and its relationship with human health, aquatic animal health, and the safety of fish and products, as well as laboratory analysis procedures and identification of control and prevention measures of this biological hazard in fish and products to safeguard public health. Full article

The Mediterranean aquaculture industry has recently been confronted with the appearance of a bile imprint on fish filets, which to-date remains of unknown etiology. This study investigates the involvement of common procedures applied before (fasting), during (confinement), and after (ice storage) fish harvesting. Two experiments were designed, one for gilthead seabream (Sparus aurata) and one for red seabream (Pagrus major). The fish were grouped according to fasting duration (1, 2, 3 days), harvesting method (stressed, unstressed), and ice storage (0 h, 48 h). In both species, the imprint appeared in all ice-stored fish for 48 h but not in fresh fish (0 h), the color of the imprint became darker as Days of Fasting increased, stressed fish had darker imprints than unstressed fish, and plasma and bile osmolality and cholesterol were significantly affected by treatments. The histological examination of the gallbladder in red seabream showed great variability in the muscularis thickness and appearance, regardless of treatment. These results are not conclusive as to the cause of the bile imprint appearance. However, they offer a first insight into an issue that bears significant impact in the marketing of aquaculture products and may foster further investigation in the search of the underlying causes of this reoccurring issue. Full article

Nile tilapia (Oreochromis niloticus) aquaculture continues to significantly contribute to the growth of the aquaculture sector in Uganda. However, its production is beset by erratic and unreliable seed supply. Also, most hatcheries practice inbreeding of broodstock, resulting in inferior seed characterized by low growth rates. As such, a selective breeding program is necessary to readily avail fast-growing seed that respond to farmers’ needs. The present review consolidates available information on developing a Nile tilapia breeding program in Uganda. The article discusses the significance of genetic improvement, drawing lessons from successful Nile tilapia selective breeding programs in other countries. From a literature review, no systematic Nile tilapia selective breeding program was traceable in Uganda. Scanty information on the selective breeding efforts of the species was available, with little evidence of selection for improved performance. Overall, the national capacity for aquaculture research and development, including fish breeding and strain improvement, was weak and poorly funded. The review recommends purposive support for developing a systematic strain improvement breeding program, which will be a source of improved broodstock and seed for hatcheries and farmers, respectively. The program would guide the formulation of standard operating procedures for quality seed production towards ensuring sustainable aquaculture growth in Uganda. Full article

Aquaculture is a globally widespread practice and the world’s fastest-growing food sector and requires technological advances to both increase productivity and minimize environmental impacts. Monitoring the sector is one of the priorities of state governments, international organizations, such as the Food and Agriculture Organization of the United States (FAO), and the European Commission. Data collection in aquaculture, particularly information on the location, number, and size of production facilities, is challenging due to the time required, the extent of the area to be monitored, the frequent changes in farming infrastructures and licenses, and the lack of automated tools. Such information is usually obtained through direct communications (e.g., phone calls and e-mails) with aquaculture producers and is rarely confirmed with on-site measurements. This study describes an innovative and automated method to obtain data on the number and placement of structures for marine and freshwater finfish farming through a YOLOv4 model trained on high-resolution images. High-resolution images were extracted from Google Maps to test their use with the YOLO model for the identification and geolocation of both land (raceways used in salmonids farming) and sea-based (floating sea cages used in seabream, seabass, and meagre farming) aquaculture systems in Italy. An overall accuracy of approximately 85% of correct object recognition of the target class was achieved. Model accuracy was tested with a dataset that includes images from Tuscany (Italy), where all these farm typologies are represented. The results demonstrate that the approach proposed can identify, characterize, and geolocate sea- and land-based aquaculture structures without performing any post-processing procedure, by directly applying customized deep learning and artificial intelligence algorithms. Full article

Oxford Nanopore Technology (ONT) allows for the rapid profiling of aquaculture microbiomes. However, not all the experimental and downstream methodological possibilities have been benchmarked. Here, we aimed to offer novel insights into the use of different library preparation methods (standard-RAP and native barcoding-LIG), primers (V3–V4, V1–V3, and V1–V9), and basecalling models (fast-FAST, high-HAC, and super-accuracy-SUP) implemented in ONT to elucidate the microbiota associated with the aquatic environment and farmed fish, including faeces, skin, and intestinal mucus. Microbial DNA from water and faeces samples could be amplified regardless of the library–primer strategy, but only with LIG and V1–V3/V1–V9 primers in the case of skin and intestine mucus. Low taxonomic assignment levels were favoured by the use of full-length V1–V9 primers, though in silico hybridisation revealed a lower number of potential matching sequences in the SILVA database, especially evident with the increase in Actinobacteriota in real datasets. SUP execution allowed for a higher median Phred quality (24) than FAST (11) and HAC (17), but its execution time (6–8 h) was higher in comparison to the other models (0.6–7 h). Altogether, we optimised the use of ONT for water- and fish-related microbial analyses, validating, for the first time, the use of the LIG strategy. We consider that LIG–V1–V9-HAC is the optimal time/cost-effective option to amplify the microbial DNA from environmental samples. However, the use of V1–V3 could help to maximise the dataset microbiome diversity, representing an alternative when long amplicon sequences become compromised by microbial DNA quality and/or high host DNA loads interfere with the PCR amplification/sequencing procedures, especially in the case of gut mucus. Full article

The sustainable utilization of co-products derived from the salmon processing industry is crucial for enhancing the viability and decreasing the environmental footprint of both capture and aquaculture operations. Salmon (Salmo salar) is one of the most consumed fish worldwide and a major species produced in aquaculture. As such, significant quantities of salmon co-products are produced in pre-commercialization processing/steaking procedures. The present study characterized a specific co-product derived from the processing of salmon: minced salmon heads. More specifically, this work aimed to reveal the nutritional profile of this co-product, with a special focus on its lipid content, including thoroughly profiling fatty acids and fully appraising the composition in complex lipids (polar lipids and triglycerides) for the first time. The antioxidant potential of lipid extracts from this salmon co-product was also studied in order to bioprospect lipid functional properties and possibly unveil new pathways for added-value applications. Our analysis indicated that these minced salmon heads are exceptionally rich in lipids. Oleic acid is the most prevalent fatty acid in this co-product, followed by palmitic acid, stearic acid, and linoleic acid. Moreover, relevant lipid indexes inferred from the fatty acid composition of this co-product revealed good nutritional traits. Lipidome analysis revealed that triglycerides were clearly the predominant lipid class present in this co-product while phospholipids, as well as ceramides, were also present, although in minimal quantities. The bioprospecting of antioxidant activity in the lipid extracts of the minced salmon heads revealed limited results. Given the high concentration of triglycerides, minced salmon heads can constitute a valuable resource for industrial applications from the production of fish oil to biodiesel (as triglycerides can be easily converted into fatty acid methyl esters), as well as possible ingredients for cosmetics, capitalizing on their alluring emollient properties. Overall, the valorization of minced salmon heads, major co-products derived from the processing of one of the most intensively farmed fish in the world, not only offers economic benefits but also contributes to the sustainability of the salmon processing industry by reducing waste and promoting a more efficient use of marine bioresources. Full article

Vaccination is an effective, cost-efficient method to preventing disease outbreaks. However, vaccine procedures can induce adverse reactions due to stress, increasing plasma cortisol in the short term. In this context, tryptophan may prove to be fundamental as it has been demonstrated to have various desirable neuroendocrine attributes in different fish species. Therefore, this study aimed to evaluate both short-term (3 days) and long-term (21 days) effects of dietary tryptophan supplementation on European seabass juveniles’ (26.23 ± 7.22 g) response to vaccination and disease resistance to Tenacibaculum maritimum. The short-term tryptophan-fed fish exhibited increased hepatic superoxide dismutase and plasma cortisol levels, along with the downregulation of immune-related genes. Despite these changes, disease resistance was unaffected. When fish were later dip vaccinated, tryptophan prevented the stress-induced plasma cortisol increase and upregulated the gene expression of igm, suggesting tryptophan’s role in enhancing vaccination efficiency by counteracting stress-associated effects. In the long term, the lowest supplementation dose counteracted vaccine-mediated reduced gene expression, and fish fed this diet showed a more modest molecular response. Overall, the findings suggest a complex interplay between tryptophan supplementation, immune responses, and vaccine efficiency in fish. Further research is necessary to clarify how tryptophan could consistently improve vaccine efficiency in aquaculture. Full article