Aquaculture Journal

The farming and rearing of freshwater fishes is increasing in scale in response to growing global food demands, but notably also through the increasing popularity of sport angling and expansion of ornamental hobbyist practices globally. Alongside rises in numbers of fish and the intensity of their rearing, increases in aquatic and ecosystem stressors have expedited the emergence and motility of many pathogenic diseases. Cyprinids are the most popular species for culturing, and although largely considered hardy, are susceptible to a diverse array of pathogens. Common carp (Cyprinus carpio) and ornamental koi carp (Cyprinus rubrofuscus) are valued for their ease of cultivation, fast growth rates, and variety of genetic appearances. Vaccination programmes have become a mainstay of industrial aquaculture where financially viable, but their use in fish reared as companion animals or for sport angling is not cost-effective and despite the magnitude and growth of these markets, much less is known about current threats and trends in this area of aquaculture. Here, we review the bacterial, viral, and fungal infections commonly found within carp bred for angling and ornamental aquaculture in the United Kingdom and Europe, alongside current threats such as antimicrobial resistance and the potential impact of climate change on temperature-dependent infections. We highlight the evolution of diagnostic techniques, alternative therapies to reduce antibiotic dependence, and the environmental impact of available treatments as priority areas for cyprinid research. Additionally, there is an urgent need for novel therapeutics in this area, as innovation is currently lacking. Full article

This study evaluated the effects of dietary folic acid supplementation on growth performance, antioxidant- and immune-related gene expression, and the response to acute hepatopancreatic necrosis disease (AHPND) in Pacific white shrimp (Penaeus vannamei). Juveniles (12 shrimp per tank; four replicate tanks per treatment) were fed diets containing nominal supplemental folic acid levels of 0, 2, 5, or 10 mg kg⁻¹ for 35 days, and 30 shrimp per dietary treatment (three replicate aquaria; 10 shrimp per aquarium) were subsequently challenged with an AHPND-causing strain of Vibrio parahaemolyticus. Among the supplementation levels evaluated, the 5 mg kg⁻¹ diet produced the highest final weight (14.8 ± 0.5 g), weight gain (7.9 ± 0.3 g), a specific growth rate (2.14 ± 0.1% day⁻¹), and the lowest apparent feed conversion ratio (1.3 ± 0.1), whereas the Control showed values of 12.3 ± 0.7 g, 5.4 ± 0.3 g, 1.6 ± 0.1% day⁻¹, and 1.6 ± 0.1, respectively (p ≤ 0.05). Dietary folic acid modulated the relative expression of antioxidant-related genes (SOD, CAT, and GPX) in the gills and hepatopancreas and altered basal and post-challenge expression of the immune-related genes ALFP, CTL3, GILT, MNK, and SR in the gills. At 72 h post-challenge, final cumulative mortality differed among treatments (F_3,8 = 5.405, p = 0.025), with lower mortality in T5 (36.7 ± 7.6%) than in the Control (53.3 ± 2.9%; Tukey, p = 0.022). These findings indicate that dietary folic acid supplementation influenced growth performance, challenge outcomes, and transcriptional responses in juvenile Penaeus vannamei. Among the supplementation levels evaluated, the 5 mg kg⁻¹ diet consistently produced the most favorable combination of growth performance, lower final challenge mortality, and modulation of antioxidant- and immune-related gene expression. Full article

Reliable aquaculture monitoring requires spatial, administrative, and environmental evidence to be integrated without treating these sources as equivalent. This study characterized mapped aquaculture land-cover dynamics in six coastal provinces of Ecuador from 1985 to 2024, assessed their 2023 correspondence with authorized or concessioned shrimp-farm area, quantified 2023–2024 land-cover transitions, and described climate exposure over a fixed historical aquaculture footprint. Annual MapBiomas Ecuador Collection 3.0 classifications were aggregated by province, canton, and parish; MPCEIP records were harmonized with INEC administrative codes; and CHIRPS v3 precipitation and ERA5-Land temperature were summarized over the union of all pixels mapped as aquaculture at least once during the study period. Mapped class 31 area increased from 58,198.792 ha in 1985 to 138,200.970 ha in 2024, with a maximum of 153,516.642 ha in 2022. In 2023, mapped area represented 74.508% of 202,114.900 ha of authorized or concessioned area, with strong canton-level rank correspondence. Between 2023 and 2024, persistence reached 135,774.430 ha, gross loss 14,816.766 ha, gross gain 2426.130 ha, and net change −12,390.636 ha. Climate exposure was wettest in 1998 and warmest in 2023. Together, the results show that coastal aquaculture development cannot be inferred reliably from a single territorial measure: long-term mapped expansion, administrative extent, recent classification changes, and climate exposure describe complementary but non-equivalent dimensions of the system. This distinction provides a more defensible basis for interpreting aquaculture land-use change and for targeting territorial monitoring and administrative verification. Full article

The rapid expansion of global aquaculture and increasing demand for sustainable protein sources have intensified the search for alternatives to conventional fish meal. Wolffia globosa, the smallest and fastest-growing flowering plant, has emerged as a promising yet underutilized aquatic resource with significant potential in aquaculture nutrition and sustainable food systems. Despite growing interest in aquatic plant-based proteins, comprehensive evaluation of W. globosa across nutrition, cultivation, and application systems remains limited. This review synthesizes current knowledge on its biology, nutritional composition, functional properties, and application potential in aquaculture and circular bioeconomy systems. W. globosa exhibits rapid vegetative propagation, high biomass productivity, and minimal resource requirements, enabling efficient cultivation in nutrient-rich environments. It contains high-quality protein (20–48% dry weight), essential amino acids, polyunsaturated fatty acids, dietary fiber, vitamins, minerals, and diverse bioactive compounds with antioxidant and immunomodulatory properties. Feeding studies demonstrate its potential to enhance growth performance, feed efficiency, and physiological health in aquatic species. Additionally, its capacity to absorb nitrogen and phosphorus supports nutrient recycling and water quality improvement in integrated aquaculture systems. However, variability in nutrient composition, limited large-scale cultivation data, insufficient long-term feeding trials, and uncertain economic feasibility at industrial scale remain key challenges for its commercial adoption. Overall, W. globosa represents a promising but still developing biomass resource with strong potential to reduce dependence on fish meal while supporting environmentally efficient aquaculture and future food systems. Future research should focus on optimizing cultivation practices, developing efficient processing technologies, and validating long-term feeding performance to facilitate its large-scale adoption. Full article

Yeast (Saccharomyces cerevisiae) and its various fractions are assessed as sustainable functional feed additives that address both nutritional requirements and health challenges in intensive aquaculture systems. This review is based upon existing knowledge of yeast-derived products, critically evaluating their applications within aquafeeds. Specifically, it explores the use of whole yeast, yeast cell walls, autolysates, hydrolysates, and individual bioactive compounds. The main emphasis is placed on the yeast products containing β-glucans, mannanoligosaccharides (MOS), nucleotides, and other bioactive compounds, which provide significant advantages for enhancing innate and adaptive immunity, thus modulating gene expression, and raising antioxidant responses across diverse aquaculture species. We state the optimal inclusion levels from the scientific literature, which may range from as low as 0.1% for whole yeast products and about 0.4% for specific fractions, though species-specific responses vary considerably. Furthermore, this review integrates some of these areas to present a cohesive overview of different mechanisms of action, species-specific applications, physiological impacts on the gut, and related organ and systemic health. We also note specific haematological parameters and disease resistance across fish and crustacean species that may be affected by yeast products. By integrating the mechanistic insights with production-oriented application, this review fills the knowledge gap by establishing a framework for the powerful nature of yeast’s multiple roles in aquaculture nutrition. It serves to scope the potential future of commercial technologies leading to novel yeasts as functional feed additives. Although the literature suggests potential benefits for growth, immunity, antioxidant status, and gut health, the magnitude of response is highly variable amongst investigations. Full article

To explore the optimization effects of fixed aquatic water treatment materials combined with immunomodulatory agents on the ecosystem and farming efficiency of Litopenaeus vannamei in high-water-level ponds, this study established experimental ponds (with fixed aquatic water treatment materials and feed supplemented with chitosan oligosaccharides) and control ponds (no fixed water treatment materials applied, fed with basal feed only). Through a comparative trial over a complete farming cycle, the study systematically analyzed changes in plankton community structure and diversity, water physicochemical factors, shrimp growth performance, immune indicators, and muscle nutritional composition. The results showed that in the experimental group, diatoms (Ditylum brightwellii and Skeletonema) dominated the plankton community, while the density of harmful blue-green algae (Oscillatoria and Trichodesmium) significantly decreased, and planktonic animal diversity improved in the later stages. Among the water physicochemical indicators, the experimental group exhibited a 50% reduction in nitrite levels by the later stages, significantly higher than the 33.33% reduction in the control group. Total ammonia nitrogen levels remained lower than those in the control group, with a smaller increase in the later stages. Total phosphorus levels were significantly lower in the experimental group after 80 days, and the later-stage decline in chemical oxygen demand was 11.65% higher than that in the control group. Shrimp body weight increased significantly by 13.23%, while hepatosomatic index, musculosomatic index, and immune enzyme (acid phosphatase and total antioxidant substances) activity also improved markedly. The content of unsaturated fatty acids (linoleic acid and oleic acid) in the muscles significantly increased. The study demonstrated that the combined application of fixed aquatic water treatment materials and chitosan oligosaccharide preparations can optimize the farming water environment, enhance shrimp growth performance and quality, and provide technical support for the ecological cultivation of Litopenaeus vannamei. Full article

Antimicrobial resistance (AMR) in aquaculture environments has become an increasing concern due to the dissemination of antibiotic-resistant bacteria in aquatic ecosystems. This study investigated the occurrence of presumptive antimicrobial-resistant bacteria in commercial fish farms in Hajdú-Bihar county, Hungary. Between 2023 and 2024, water samples were collected from fishponds from Hajdúszoboszló, Biharugra, and Debrecen, followed by membrane filtration with 0.45 µm pore size mixed cellulose ester membrane filters, bacterial isolation using selective media including vancomycin-resistant enterococci (VRE) agar, Eosin Methylene Blue (EMB) agar, and Endo’s medium. The phenotypic characterization revealed the presence of diverse bacterial populations that could be associated with potential antimicrobial resistance. Bacterial identification using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) showed several bacterial genera, predominantly Acinetobacter, Pseudomonas, Enterococcus, Bacillus, and Escherichia. A total of 16 presumptive antimicrobial-resistant bacterial isolates recovered from selective media were identified using MALDI-TOF MS. Several detected species, including Acinetobacter baumannii, Pseudomonas aeruginosa, Enterococcus faecium, and Enterococcus faecalis, are recognized as opportunistic bacteria associated with antimicrobial resistance dissemination. The findings demonstrate that aquaculture waters in Hajdú-Bihar county may serve as reservoirs of antimicrobial-resistant bacteria. Full article

Laos is one of the 32 landlocked developing countries (LLDCs) of the world, where isolation from the sea and the lack of a large-scale fishing industry have a direct effect on fish supply and fish consumption. Per capita fish consumption in LLDCs amounted to 5.1 kg/year in 2023, which is much lower than the world average (20.3 kg) as well as the Developing Regions average (20.0 kg). However, per capita fish consumption in Laos has reached 28.5 kg/year in 2023, representing the highest among the 32 LLDCs. Relying on the results and experiences of several decades of work in aquaculture development in Laos and taking into account the observations of local and international publications, documents and statistics included, the authors aimed at identifying the principal reasons for the elevated fish consumption in Laos from different perspectives, including that of aquaculture, as well as Lao language, culture, and religion. In this review, the authors analyzed the availability of aquatic resources, the role of fishing and aquaculture in the Lao economy and social life, market realities, as well as the importance of fish in Lao culture. Full article

The study evaluated the bioremediation potential of a commercial probiotic composed of multi-strain Bacillus (B. subtilis CCT 0089, B. amyloliquefaciens ATCC 31592, B. licheniformis CCT 7836 and B. megaterium CCT 7935) in biofloc technology (BFT). In vitro, the ideal dosage was identified between concentrations [0.01], [0.10], [1.00], and [10.00] g m⁻³. Additionally, the growth of probiotic species was characterised in different temperature and oxygen conditions, resistance in 3.0% sodium chloride culture medium, enzyme production (protease, amylase, and lipase) and antibacterial activity. The in vivo experiment evaluated the bioremediation potential of the probiotic and its impact on the growth performance of Nile tilapia Oreochromis niloticus raised in BFT conditions. The group that received the multi-strain Bacillus probiotic at a dosage of 0.10 g m⁻³ experienced a decrease in floc volume, toxic ammonia, and nitrate levels, leading to environmental enhancements and improved well-being for the cultured organisms. It is advisable to use the multi-strain probiotic at a dosage of 0.10 g m⁻³ in BFT conditions. Full article

Acute hepatopancreatic necrosis disease (AHPND) is one of the most devastating bacterial diseases affecting Pacific white shrimp (Litopenaeus vannamei) aquaculture worldwide. Although Vibrio parahaemolyticus has been recognized as the principal causative agent of AHPND, increasing evidence indicates that Vibrio campbellii also plays an important role in disease outbreaks. The present study investigated the pathogenicity and temporal dynamics of pirA transcription in V. campbellii isolated from cultured L. vannamei. The isolate was identified by 16S rRNA sequencing, and pirA expression was quantified during bacterial growth under in vitro conditions and throughout experimental infection in vivo using quantitative real-time PCR. In vitro, pirA transcription increased rapidly during the exponential growth phase and reached its highest level at 6 h after incubation, followed by a gradual decline despite continued bacterial growth. Immersion challenge experiments using juvenile shrimp (1 × 10⁶ CFU/mL) resulted in cumulative mortality exceeding 90% within 48 h post-infection. In vivo, pirA transcription remained relatively low during the early stage of infection but increased markedly at 36 h post-infection, coinciding with rapid mortality and severe hepatopancreatic damage. Histopathological examination revealed progressive epithelial cell sloughing, degeneration of B- and F-cells, tubular collapse, and extensive tissue necrosis, which are characteristic lesions of AHPND. These findings demonstrate that V. campbellii possesses strong pathogenic potential. Temporal induction of pirA transcription was closely associated with severe hepatopancreatic lesions and mortality during experimental infection. Collectively, these findings provide new insights into the temporal dynamics of pirA transcription during AHPND progression and its association with tissue pathology and mortality, supporting the development of early molecular diagnostics, disease surveillance, and biosecurity strategies for sustainable shrimp aquaculture. Full article

Functional feed ingredients with antimicrobial activities are being explored as a tool to mitigate diseases in Atlantic salmon (Salmo salar L.). Skeletonema marinoi is a marine diatom known to have antimicrobial activity. Here, two separate experiments, including a growth study (Exp. 1) and a bacterial challenge (Exp. 2), were conducted to evaluate the effects of dietary S. marinoi as a functional feed ingredient on the growth, feed utilization, stress biomarkers, antioxidant defense, and immunogenic responses of Atlantic salmon. In Exp. 1, a 16-week growth trial was conducted in a recirculating aquaculture system (RAS) stocked with ten fish (59.6 ± 1.6 g, initial weight) in each of five replicate tanks per treatment. Fish were fed twice daily with either the reference diet or the reference diet supplemented with 0.5% S. marinoi. In Exp. 2, a 27-day bacterial challenge with Vibrio anguillarum Serotype O3 (SO3) was conducted in RAS using 36 fish (100–150 g) per 150 L tank in triplicate. Fish were acclimatized to the RAS for 14 days and fed twice daily with the reference or 0.5% S. marinoi diet prior to the bacterial challenge. Blood plasma, liver, and intestine samples were collected after the growth trial, before (initial, 0 day) and post-challenge (5, 10, 27 days). The results indicated that in Exp. 1, there were no significant differences in survival, final weight, weight gain, feed intake, feed efficiency, condition factor, and hepatosomatic index between fish fed the reference diet and 0.5% S. marinoi diet (p > 0.05). In Exp. 2, before challenge, Atlantic salmon fed the diet with 0.5% S. marinoi showed significantly higher superoxide dismutase (SOD) activity in comparison to fish fed the reference diet. On day 5 post-challenge, significantly higher hepatic malondialdehyde (MDA) was measured in the 0.5% S. marinoi group compared to the reference group. Plasma immunoglobulin M (IgM) level increased (p < 0.05), and intestinal IgM gene expression was up-regulated after challenge in fish fed 0.5% S. marinoi, in contrast to those fed the reference diet at 27 days post-challenge (p < 0.05). Overall, these findings suggest that S. marinoi is more likely to be associated with immune modulation rather than adverse stress response; however, further work is required to confirm pathogen-specific immunity. Full article

Bacterial stomatitis, or mouth rot (MR), caused by Tenacibaculum maritimum, is a persistent health issue for farmed Atlantic salmon (Salmo salar) in seawater, leading to elevated mortality and reduced growth during the early months of production. Despite its impact, economic estimates of MR have been lacking. We developed a model to estimate selected direct costs associated with MR at the farm and industry levels in British Columbia (BC), Canada. This model incorporated parameters directly affected by MR, including revenue loss from mortality, and antibiotic treatment costs, while accounting for the feed-cost offset associated with mortality. To address variability across farms, MR-associated mortality, non-MR mortality, smolt weight, the number of treatments for MR, fish sale price, feed price, price of drug, and the proportion of farms affected by MR were simulated (Monte Carlo simulation with 10,000 iterations) using ModelRisk. Results indicated that MR imposed an average farm-level economic burden of USD 0.74 million (SD: USD 0.45 million) per production cycle and an industry-level burden of USD 10.58 million (SD: USD 6.54 million) annually. This study provides model-based estimates of selected direct economic costs associated with MR, based on BC specifications, and highlights the need for improved mitigation strategies and policy prioritization for this disease. Full article

This study presents the development and application of an integrated Geographic Information System (GIS)-based Marine Spatial Planning (MSP) framework for identifying suitable offshore aquaculture development zones in Cyprus. The methodology, developed within the OS AQUA project, combines environmental exclusion analysis, weather and proximity assessment, stakeholder and policy evaluation, and carrying-capacity estimation within a unified spatial decision-support framework. A sequential three-phase analytical workflow was applied to progressively refine candidate offshore areas under environmental, operational, infrastructural, regulatory, and governance considerations. The analysis identified four candidate offshore aquaculture zones in Cyprus—Xylofagou West, Larnaka (Faros area), Governor’s Beach, and Aphrodite Hills/Avdimou—demonstrating comparatively favourable conditions for offshore aquaculture development. The results highlight the importance of integrating environmental compatibility, operational feasibility, accessibility, stakeholder acceptance, and sustainability considerations within offshore aquaculture planning processes. Carrying-capacity assessment further indicated substantial offshore production potential under precautionary operational assumptions. Beyond the Cyprus case study, the proposed GIS-MSP framework offers a transferable methodological roadmap for offshore aquaculture zoning, Allocated Zones for Aquaculture (AZA) establishment, and sustainable marine spatial planning in the Mediterranean region. Full article

The contamination of aquaculture products and effluents by Emerging Contaminants (ECs)—originating from both direct chemical applications and peripheral industrial activities—represents a critical global concern due to the environmental and public health risks associated with their persistence, bioaccumulation, and environmental dispersion. This systematic review aimed to synthesize the available scientific evidence on the occurrence, sources, environmental and human health impacts, and mitigation strategies of ECs in aquaculture production systems. A systematic literature search was conducted following the PRISMA 2020 guidelines across the Web of Science, Scopus, and Google Scholar databases. Studies were selected according to predefined eligibility criteria, resulting in a total of 137 studies included in this review. The findings indicate that these pollutants accumulate within the tissues of farmed organisms, posing direct ingestion risks to humans, while contaminated effluents facilitate the widespread degradation of receiving water bodies. Given their environmental persistence and ubiquitous distribution, there is an urgent need for advanced analytical methodologies, robust regulatory frameworks, and the implementation of sustainable treatment technologies—such as advanced oxidation processes and recirculating aquaculture systems—alongside strategies for reducing antibiotics and microplastics. These measures are essential to mitigate the prevalence of ECs and safeguard both ecosystem integrity and human health. Full article

Anesthetic agents are widely used in aquaculture to facilitate handling, transport, surgery, vaccination, tagging, and other husbandry procedures. However, most previous reviews have primarily focused on induction time, recovery duration, and welfare outcomes, with comparatively limited emphasis on blood physiology as an indicator of systemic anesthetic safety. The present review synthesizes current evidence regarding hematological, hemato-biochemical, blood gas, and immunohematological alterations induced by major anesthetic classes in aquaculture species. Literature published between 2000 and 2026 was retrieved from Scopus, Web of Science, Google Scholar, PubMed, ScienceDirect, and Springer Nature databases, with approximately 150 studies included following structured screening. Available evidence indicates that anesthetic exposure frequently alters erythrocyte and leukocyte profiles, cortisol secretion, glucose and lactate metabolism, hepatic enzyme activity, electrolyte balance, acid–base regulation, and blood oxygen transport. Respiratory depression, hypercapnia, hypoxemia, and transient metabolic acidosis were recurrent consequences of deep anesthesia, particularly during prolonged exposure or unfavorable environmental conditions. Several anesthetics also modulated innate immune responses through alterations in complement activity, respiratory burst function, cytokine signaling, and leukocyte redistribution. Collectively, the review highlights blood physiology as an essential framework for evaluating anesthetic safety and improving welfare-oriented aquaculture practices. Full article

Two growth trials were conducted to evaluate the effects of solvent-extracted soybean meal (SBM), low-oligosaccharide soybean meal (LO-SBM), and enzyme-treated soybean meal (ET-SBM) on the growth performance, feed utilization, and gut microbiome of the Pacific white shrimp (Litopenaeus vannamei). Nine diets were tested, including a basal diet using solvent-extracted soybean meal as the main protein source. The solvent-extracted soybean meal was then replaced with LO-SBM or ET-SBM at 40%, 60%, 80%, and 100% on an isonitrogenous and isolipidic basis. In the 8-week outdoor green water trial, all growth metrics, FCR and apparent net protein retention (ANPR) showed no significant differences among diets (p > 0.05). However, there was a significant effect of LO-SBM on phosphorus retention. In the clear water trial, intermediate inclusion levels of LO-SBM (60–80%) slightly improved growth metrics and phosphorus retention (p < 0.05) without affecting protein utilization, while 100% LO-SBM did not provide additional benefits. Diets with ET-SBM showed similar performance; however, phosphorus retention was reduced. Diets did not affect whole-body composition (p > 0.05), except for phosphorus and moisture. Gut microbiota analysis revealed that shrimp fed 100% ET-SBM had notably higher alpha diversity (Shannon index = 5.45, observed species = 326.41) compared to those fed 100% LO-SBM (Shannon index = 4.59, observed species = 242.69), indicating improved microbial stability with ET-SBM. Nonetheless, there were no significant differences in beta diversity or taxonomic composition between treatments (p > 0.05). This study demonstrates that incorporating 60–80% LO-SBM into the diet improves shrimp growth and nutrient utilization. Additionally, ET-SBM may also support shrimp growth, nutrient efficiency, and microbial diversity, suggesting that both LO-SBM and ET-SBM can be beneficial for shrimp nutrition. Full article

Digestibility is a fundamental concept in animal nutrition and is widely used to evaluate feed ingredients. Although digestibility values are generally expected to be positive, negative values are occasionally reported. Negative values are not analytical or calculation errors; rather, they often convey critical information about feed ingredients. Negative digestibility is most commonly observed for minerals, which readily interact with other components in compound feeds and within the gut lumen. A proper understanding of negative digestibility is therefore essential for formulating nutritionally complete diets. This paper introduces Mellanby’s toxamin theory to illustrate the mechanisms underlying negative digestibility. It also explains the rationale behind digestibility calculations, which sometimes yield mathematically extreme and biologically unrealistic negative values. Finally, the paper proposes in vivo mineral-binding capacity as an alternative metric for expressing ingredient interactions, as negative digestibility values themselves can lead to confusion and misinterpretation. By reinterpreting the biological significance of negative digestibility, this paper seeks to translate an often-confusing observation into a more practical and informative nutritional index. Full article

In this study, total ammonia nitrogen (TAN) excretion rates were quantified in juvenile (mean weight: 1.79 ± 0.17 g) and adult (mean weight: 15.91 ± 0.63 g) prawns (Macrobrachium caementarius) reared under recirculating aquaculture system (RAS) conditions representative of small-scale farming operations. Prawns were fed a commercial dry pelleted diet (48.5% crude protein) at a daily ration equivalent to 5% of total biomass. Water quality parameters were maintained within species-specific tolerance ranges to ensure normal physiological and metabolic function. TAN excretion rates were estimated using a mass balance approach under closed-flow batch conditions. A significant difference in TAN excretion was observed between life stages (p = 0.008): juveniles excreted 0.009 ± 0.006 mg TAN g⁻¹ h⁻¹ (0.22 ± 0.18 mg TAN g⁻¹ day⁻¹), whereas adults excreted 0.03 ± 0.01 mg TAN g⁻¹ h⁻¹ (0.73 ± 0.06 mg TAN g⁻¹ day⁻¹). Distinct diel postprandial patterns were evident in both life stages, with peak TAN release occurring 1–2 h after each feeding event, followed by a gradual decline. These life-stage differences have direct implications for RAS design and biofilter management and should be interpreted in the context of the dietary conditions used. The quantified excretion rates provide baseline bioengineering parameters for sizing biofilters, estimating nitrogen loading, and optimizing water quality management for this emerging aquaculture species. Full article