Aquaculture International最新文献

Aquaculture has emerged as a cornerstone of global food production, yet infectious diseases continue to threaten its productivity and sustainability. In teleost fish, mucosal surfaces such as the skin, gills, gut, and nasopharynx serve as vital immune barriers and primary sites of host–pathogen interaction. This review synthesizes current understanding of the cellular and molecular mechanisms underpinning fish mucosal immunity, with emphasis on mucosa-associated lymphoid tissues (MALTs), including GALT, SALT, GIALT, and NALT. It highlights the pivotal role of immunoglobulin T (IgT) as a functional analogue of mammalian IgA and its interplay with resident microbiota in maintaining mucosal homeostasis. Advances in functional feeds, probiotics, and immunostimulants are discussed as promising strategies to enhance mucosal resilience. Particular attention is given to the development of mucosal vaccines and adjuvants, exploring diverse delivery routes—immersion, oral, and nasal, and the molecular pathways, including Toll- and NOD-like receptor signaling, that modulate immune activation. Emerging technologies such as single-cell transcriptomics, immunoinformatics, and microbiome–transcriptome integration are reshaping our capacity to characterize mucosal responses and design precision vaccines. Despite these advances, challenges remain in antigen stability, regulatory approval, and the establishment of correlates of mucosal protection. Addressing these gaps through species-specific, microbiota-informed vaccine design and integrative immunological approaches will be crucial for advancing disease management and promoting sustainable aquaculture.

This study investigated the effects of supplementing high soybean meal diets with alpha-ketoglutaric acid (AKG) on the intestinal health and growth performance of spotted sea bass (Lateolabrax maculatus). A total of 270 fish (average weight 7.48 ± 0.05 g) were randomly divided into 6 groups (3 replicates each, 15 fish per tank): negative control (FM, 44% fish meal), positive control (HSB, 22% fish meal + 40% soybean meal), and four experimental groups fed the HSB supplemented with 0.5%, 1%, 1.5%, and 2% AKG, respectively. Fish were fed twice daily for 56 days, with serum biochemical indices, foregut histology, and inflammatory gene expression detected post-experiment. The research results are as follows: Diets high in soybean meal impaired growth, as seen in significantly lower weight gain (WG), specific growth rate (SGR), biomass gain (BG), and daily feed intake (DFI) compared to the FM group; AKG supplementation did not alter these growth parameters significantly. Histological examination of the foregut revealed that fish fed the high soybean meal diet exhibited pronounced intestinal damage compared with those receiving the fish meal diet. This injury was accompanied by a marked upregulation of the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α). However, dietary supplementation with 1.5% AKG mitigated these effects: TNF-α expression was significantly reduced, while the anti-inflammatory cytokine interleukin-10 (IL-10) was concurrently elevated, indicating a shift toward an anti-inflammatory milieu. In terms of serum biochemical indices, supplementation with 1.5% AKG significantly elevated the levels of complement 3 (C3), alkaline phosphatase (AKP), lysozyme (LZM), and glutathione (GSH) in the serum. The findings indicate that a high soybean meal diet causes intestinal damage and reduces the growth performance of spotted sea bass, while the supplementation of AKG fails to enhance their growth performance and has limited ability to repair intestinal damage.

Aquaculture plays a significant role in the food chain and in rural economies. Continuous water quality monitoring, health management, real-time growth monitoring, and biomass estimation are critical aquaculture activities. Recent advances in computer vision, image processing, and Artificial Intelligence (AI), particularly in Machine Learning (ML) and Deep Learning (DL), enable the control, drive, and solve the problems related to daily real-time aquaculture activities. The performance of various ML and DL models and the quality and availability of public datasets in this domain remain underexplored, and the redefinition of the role of AI in aquaculture is the motivation for this study. This survey aims to analyse and evaluate various methods and datasets for monitoring water quality, estimating fish biomass, disease prediction, and behavioural analysis, to highlight recent developments and to seek the attention of researchers to address the challenges and concerns of aquaculture systems. Currently, there is no single, generalised AI model capable of performing all essential aquaculture activities using continuous time-series data generated from diverse, heterogeneous ponds across a wide geographical area. To address this gap, a 5G-enabled Federated Learning (FL) framework utilising Unmanned Aerial Vehicles (UAV) for cooperative data collection and model training is highly recommended.

Dietary additives, like multienzyme extracts (ME) from fisheries wastes, have emerged as functional ingredients capable of improving nutrient absorption and feed efficiency, contributing to more sustainable aquaculture practices. Considering the developmental stage is essential for optimizing the effectiveness of such additives, as their nutritional requirements and digestive capacities vary. This study evaluated the effects of a diet supplemented with ME from Pleoticus muelleri fishery waste on the physiological responses of Cherax quadricarinatus at two developmental stages: early juvenile and prepubertal. Trials involved feeding 48 juveniles (~ 4 g) and 48 prepubertal crayfish (~ 15 g; 24 females and 24 males) with a control or ME-supplemented diet (24 individuals per group). Assessed parameters included growth, digestive enzyme activity, biochemical reserves (proteins, lipids, glycogen) in the hepatopancreas and pleon muscle, intestinal microbiota composition, and morphohistological parameters. After 90 days, juveniles fed the ME diet showed higher protein content in the hepatopancreas but decreased specific enzymatic activity of peptidases and lipases, with no significant impact on somatic growth. For prepubertal crayfish, the ME diet increased specific activity of peptidases and reduced lipid accumulation in the hepatopancreas, while mass gain was significantly lower than in the control group, with a pronounced effect in males. ME supplementation modified intestinal microbiota in both stages, increasing the Firmicutes phylum, which may suggest enhanced digestion and nutrient absorption. This study demonstrates that ME supplementation modulates digestive metabolism in crayfish, with effects depending on developmental stage and sex, providing insights into the potential use of exogenous enzymes as functional feed additives in aquaculture.

Reproduction in vertebrates is primarily regulated by the gonadotropin-releasing hormone (GnRH) neuropeptide, but limited knowledge of its molecular mechanisms in Channa striata (striped murrel) affects the development of effective breeding strategies. This study aims to identify coding sequences of GnRH 3 neuropeptide of C. striata, consisting of 303 bp, encoding 66 amino acids, comprising a 7.26-kDa peptide, including a decapeptide, proteolytic sites, and species-specific GnRH-associated peptide. Molecular docking and dynamic simulation of csGnRH 3-csGnRHR depicted robust interaction (docking score − 4578.66). Further, the mature brooders of C. striata selected and injected with salmonGnRHa and gene expression analysis have been done at different time intervals, showing > eightfold increase in GnRH expression in salmonGnRHa-treated females, while no significant expression was observed in males. In females, FSH and LH expression levels increased (p < 0.05) significantly in the brain pituitary after 12 h, while negligible expression was observed in males. Histology showed different oocyte stages in female gonads; males exhibited immature testes, confirming their asynchronous behavior. Hormonal analysis showed elevated progesterone (313 ± 8 pg/mL), estradiol (349 ± 6 pg/mL), and testosterone (129 ± 3 pg/mL) in females at 6 h, aiding ovulation. In males, testosterone (96 ± 8 pg/mL) slightly increased at 6 h, but remained low, showing asynchronous maturation in murrel. This work provided molecular and structural insights into csGnRH 3 neuropeptide and will help in development of a species-specific inducing agent for induced breeding.

The pervasive contamination of aquatic environments by microplastics (MPs) and nanoplastics (NPs) presents a growing concern for the aquaculture industry, with potential impacts on animal and/or human health and ecosystem sustainability. This review evaluates the existing literature on the effects of micro- and nanoplastics (MNPs) on key aquaculture species, drawing from both laboratory studies and field data across a range of freshwater and marine environments. Field data on MNP concentrations in aquaculture environments reveal that polypropylene and polyethylene fibers are the most commonly found forms. Laboratory studies, however, often employ higher doses and different particle types, raising concerns about the ecological relevance of experimental conditions. Despite this disparity, our analysis shows that waterborne MNPs primarily elicit oxidative stress, whereas dietary exposures not only induce oxidative stress but are also strongly associated with histopathological damage and reduced growth. Our review also examines the toxicological mechanisms of MNP exposure, highlighting the roles of particle characteristics as key factors influencing toxicity. We further highlight potential mitigation strategies, such as dietary interventions with probiotics, vitamin C, and chlorella, which show promise in reducing the harmful effects of MNPs. This review emphasizes the critical need for more ecologically relevant, long-term studies, a deeper understanding of route-specific effects, and the development of standardized testing protocols to enhance the accuracy and applicability of MNP risk assessments and inform sustainable aquaculture practices.

The microsporidian Enterocytozoon hepatonaei (EHP) infects the hepatopancreas of Litopenaeus vannamei, causing hepatopancreatic microsporidiosis (HPM) and substantial economic losses in shrimp farming. To explore the interaction between L. vannamei and EHP, this study divided the shrimp samples into negative control (NC), very low (VL), medium–low (ML), medium–high (MH), and very high (VH) based on the quantitative EHP load for histopathology and transcriptomic analysis. Histopathology analysis confirmed mature EHP spore colonization, infection-proportional tissue damage, and chronic inflammatory responses. Transcriptomic analysis revealed that EHP infection and host responses exhibit a stage-specific strategy. For EHP, 49 highly expressed genes were identified to play a dominant role in infection, participating in key biological processes such as gene expression, energy metabolism, and cell cycle. For L. vannamei, GO and KEGG analyses revealed a predominant enrichment of DEGs in immune response and energy metabolism pathways. Immune-related genes, such as lectins, penaeidins, anti-lipopolysaccharide factors, chitinase, lysozyme, domeless, toll-like receptors, and members of the MCM family showed differential expression patterns, suggesting that immune system activation in shrimp coexists with EHP-manipulated immunosuppression, implying a potential mechanism by which EHP establishes chronic infection. Metabolism-related genes involved in glucose, lipid, and homeostasis exhibited altered expression, consistent with disrupted energy balance. In summary, EHP utilizes a specific host cell pathway to establish an infection, which leads to an inflammatory response and chronic damage to shrimp tissues and causes disruption of the immune system and metabolism of the shrimp.

Tilapia (Oreochromis niloticus) production and distribution play a crucial role in providing essential animal protein and socio-economic benefits that support growth and development in riverine communities. This study examines the tilapia value chain (TVC) in Abeokuta, Ogun State, Nigeria, using a multistage sampling approach. A total of 195 actors were selected, including 3 fish seed producers, 3 feed suppliers, 3 grow-out tilapia farmers, 25 fish processors, 30 wholesalers, 30 retailers, and 101 consumers, with data collected via structured questionnaires. Results show that fish processing is primarily driven by women, with the majority of processors aged between 31 and 40 years. Likewise, fish marketing is predominantly managed by women, most of whom fall within the 41 to 50 age range. A considerable number of processors are members of cooperatives, work part-time, and rely on charcoal for smoking fish. Among fish marketers both wholesalers and retailers, 52.0% fund their businesses through personal savings, and 73.3% source fish directly from farmers. Additionally, 56.7% employ paid labor, and 66.7% operate within local markets. Gender roles are clearly defined along the value chain revealing that women mainly handle pre-processing activities such as washing, descaling, and degutting, while men dominate fish seed production, feed supply, and grow-out tilapia farming. Fish transportation is exclusively undertaken by men, whereas both men and women are involved in fish folding and sticking. Notably, there is no record of farmed tilapia being exported. Key challenges facing the sector include the high cost of processing equipment and fuel/charcoal, poor fish quality, and limited market information, all of which hinder effective fish processing and marketing. Furthermore, the high cost of fish feed remains a major constraint for fish seed producers, feed suppliers, and grow-out farmers.

Piscirickettsia salmonis is the causative agent of piscirickettsiosis, a severe disease posing a major threat to the aquaculture industry, especially in salmon farming. Despite the availability of commercial vaccines, current preventive measures have shown limited efficacy, highlighting the urgent need for more effective, next-generation vaccine strategies. In this study, four putative virulence-associated proteins of P. salmonis named as TolC, BamB, LptD, and OmpA were selected to design a multi-epitope vaccine using an immunoinformatics-based reverse vaccinology approach. T-cell and linear B-cell epitopes were identified and ranked according to their antigenicity and allergenicity profiles. The selected epitopes were assembled into a chimeric vaccine construct using linkers to ensure proper folding and cleavage by proteases. The structural stability of the designed construct was assessed through physicochemical analysis with Expasy ProtParam, tertiary structure modeling via AlphaFold, and refinement by GalaxyRefine. Following the quality control of the construct, molecular docking studies were employed between Atlantic salmon TLR5 and the construct, followed by normal mode analysis, structural flexibility, and immune response analyses. Considering the stable interaction with TLR5, our findings highlight the potential of the construct that may serve as a promising candidate for novel subunit vaccine development against P. salmonis.