Mud crabs (genus Scylla) are among the most valuable crustaceans cultured in tropical and subtropical regions, particularly in Southeast Asia, where they contribute substantially to aquaculture production, coastal livelihoods, and food security. Recent advances in breeding, hatchery technologies, genetics, nutrition, health management, and farming systems have accelerated the transition from capture-based production towards more sustainable aquaculture practices. This review provides an integrated assessment of recent biological innovations and emerging technologies in mud crab aquaculture and evaluates their contributions to sustainable production. Evidence indicates that improvements in broodstock management, larval rearing, genetic characterization, formulated feeds, and farming systems, including Recirculating Aquaculture Systems (RAS), Integrated Multi Trophic Aquaculture (IMTA), and soft-shell production, have enhanced production efficiency, improved seed quality, and reduced environmental impacts. Despite these advances, large-scale hatchery production, selective breeding, disease management, feed sustainability, and commercial adoption remain important challenges. This review identifies these knowledge gaps and outlines future research priorities, including advanced genomic technologies, precision aquaculture, artificial intelligence, and climate-resilient farming strategies, to support the sustainable development of the global mud crab industry.
Smart aquaponics couples recirculating aquaculture with hydroponic plant cultivation, and a substantial body of recent research applies IoT sensing, machine learning, and edge computing to this domain. The literature, however, lacks a synthesis that maps how predictive models, system architectures, and biological context combine in deployed systems, leaving researchers and practitioners without a clear technical roadmap. This systematic literature review (SLR) addresses this gap through 10 research questions following the Kitchenham and Charters protocol and PRISMA-style screening. The search initially identified 3,123 records from six bibliographic databases and snowballing; after duplicate removal, screening, and quality assessment, 49 primary studies were retained for analysis. First, the literature has a prediction-to-control gap: 24
Blooms of potentially toxic cyanobacteria cause high losses in aquaculture worldwide. The species Nodularia spumigena produces toxin capable of significantly affecting feeding, growth rates, and mortality of shrimp in marine farms. As a result, methods for controlling cyanobacterial blooms can increase the production success. The present study was conducted on a commercial scale using six 600 m3 ponds stocked with 70 shrimp m−2 (Penaeus vannamei), in a biofloc system, lasting 15 weeks. The experimental groups were divided into unaffected ponds (WN—without Nodularia) and affected ponds (N—with Nodularia), with three replicates ponds per experimental group. Cyanobacterial blooms developed spontaneously in the ponds, and treatments were subsequently designated according to bloom occurrence. During the third week, when the blooms intensified, organic fertilizers consisting of sugarcane molasses and ground commercial feed were added as carbon and nitrogen sources, with the aim of stimulating the establishment of beneficial microbial communities while limiting cyanobacterial proliferation. The water quality parameters were similar between unaffected and affected ponds (p > 0.05). The microbial community composition was significantly different over time in both grops (p < 0.05), with the final predominance of chlorophytes. After fertilization, N. spumigena was absent in the affected group (N). The presence of NOD toxin in N. spumigena (66.37 ± 20.87 µg L−1) in the second week affected the feed intake of the shrimp and caused mortalities in affected group. However, N. spumigena and the toxin (NOD) was not detected again in the NS group after organic fertilization and the shrimps recovered. The performance results showed significant differences (p < 0.05) with higher survival and yield in the unaffected group (WN). Therefore, organic fertilization influenced the occurrence and development of Nodularia spumigena blooms, emphasizing its potential role in the dynamics of cyanobacteria in biofloc shrimp farming and supporting further research.
Tricaine methanesulfonate (MS-222) is one of the most widely used anesthetics in aquaculture management procedures and the ornamental fish trade; however, at excessive concentrations, it may induce undesirable physiological responses in fish. Thus, we evaluated the safety and reversibility of MS-222–induced anesthesia in the Amazonian flag tetra, Hyphessobrycon heterorhabdus. Fish were subjected to immersion baths at concentrations of 50, 75, 100, and 125 mg·L⁻1 for 5 min, followed by recovery in clean water. Behavioral effects and heart rate were assessed through electrocardiographic (ECG) recordings. Fish exhibited a longer latency to loss of postural reflex at 50 and 75 mg·L⁻1 (180–200 s), in contrast to 100 and 125 mg·L⁻1 (60–100 s). However, upon transfer to clean water, animals treated with 50 and 75 mg·L⁻1 recovered the postural reflex rapidly (100–120 s), whereas recovery was slower at 125 mg·L⁻1 (240–280 s). ECG tracings demonstrated a concentration-dependent reduction in heart rate, accompanied by increased duration of the R–R, P–Q, and S–T intervals, as well as the QRS complex. However, anesthesia did not alter the amplitude of the cardiac electrical impulse in the fish. After recovery, ECG components returned to baseline parameters similar to those of the control group, with no subsequent irregularities in cardiac rhythm. Therefore, it is concluded that the most effective concentrations of MS-222 for H. heterorhabdus range from 75 to 100 mg·L⁻1, considering response time and amount of substance used, thereby providing a safe window for anesthetic induction in this species.
The oyster pompano (Trachinotus anak) is an emerging aquaculture species in Asia with limited genomic resources. This study constructed a SNP-based genetic linkage map and performed a genome-wide association study (GWAS) to identify loci associated with growth and flesh color traits. A total of 42,667 SNP markers were generated from sequencing, of which 5360 high-quality SNPs were retained after stringent quality filtering for GWAS, while 21,356 SNPs were retained for linkage map construction. The linkage map comprised 24 linkage groups, providing a robust genomic framework for marker ordering and trait mapping. GWAS identified 105 SNPs significantly associated with body weight, along with additional SNPs linked to other growth traits, indicating a polygenic genetic architecture. In contrast, only limited associations were detected for flesh color traits. Annotation of genomic regions surrounding significant and suggestive SNPs identified ten candidate genes shared among growth traits, including Neuroligin-4, MTFMT, Urah, AGRN, IL1RAP, col27a1b, CASKIN2, CYBA, VPS35, and LEPR. These genes are involved in key biological processes such as cytoskeletal organization, energy metabolism, mitochondrial function, and skeletal development. Gene Ontology enrichment analysis further revealed significant pathways related to growth and metabolism, including muscle hypertrophy and protein hormone receptor activity. Overall, these findings provide valuable genomic resources and insights into the genetic architecture of economically important traits in T. anak, supporting future genomic selection and breeding programs.
Black soldier fly larvae (BSFL, Hermetia illucens) are promising alternatives to fishmeal in aquafeeds, but their use in salmonid diets may be limited by deficiencies in essential amino acids. This study evaluated whether substrate-biofortified BSFL could serve as a nutritional alternative to crystalline amino acid supplementation in diets for rainbow trout (Oncorhynchus mykiss). Four isonitrogenous and isolipidic diets were tested: a fishmeal control (D1), a diet with complete fishmeal replacement by defatted BSFL (D2), a BSFL diet supplemented with crystalline amino acids (D3), and a diet containing biofortified BSFL produced on spirulina- and flaxseed-enriched substrates (D4). Juvenile trout (initial weight 28.6 ± 3.9 g) were reared for 8 weeks in a recirculating aquaculture system. Overall biomass gain was not significantly affected by dietary treatment. In contrast, feed intake, feed conversion ratio (FCR), and specific growth rate (SGR) differed significantly among diets (p < 0.001). Fish fed the BSFL diet without amino acid correction (D2) showed higher feed intake and a higher feed conversion ratio (FCR = 1.26) than the other treatments. The hepatosomatic index was also higher in D2 (p = 0.009), whereas fish fed the biofortified BSFL diet (D4) exhibited the lowest values. Whole-body composition was largely unaffected by dietary treatment, although fish fed D4 showed slightly higher whole-body lipid content than fish in the other treatment groups (p = 0.041). Plasma AST and ALT activities were elevated in D2 (p < 0.05), while other biochemical parameters remained similar across treatments. Histological observations indicated reduced mucosal fold width and mucosal thickness in fish fed D2, whereas fish fed D3 and D4 showed intestinal morphology comparable to the control. Taken together, these results suggest that amino acid limitations in BSFL-based diets can affect feed efficiency and intestinal structure in rainbow trout. However, these effects were mitigated by either crystalline amino acid supplementation or substrate biofortification of the insect biomass. Biofortified BSFL therefore appears to be a promising approach to improve the nutritional value of insect-based ingredients for salmonid aquafeeds.
The hydroxysteroid dehydrogenase (HSD) family is essential for steroid metabolism and gonadal development in vertebrates, but its roles in invertebrates remain unclear. In the sea urchin Mesocentrotus nudus, four HSD genes (HSD17B7, HSD17B8, HSD17B12b, and HSD11B1-like), were identified from the gonadal transcriptome. All of these genes were highly expressed in gonads, with HSD17B8, HSD17B12b and HSD17B7 significantly enriched in testes, while the expression of HSD11B1-like did not significantly differ between the testes and ovaries. Given the differential expression of estrone-3-glucuronide between the testes and ovaries in differentiated gonads, we conducted coelomic injections of estrone-3-glucuronide to assess its effects on growth, gonadal development, and HSD gene expression in female sea urchins. No significant changes were observed in gonadal histology or growth within 21 days post injection. However, transcript levels of all four HSD genes exhibited time-dependent fluctuations. This work provides insights into the molecular mechanisms of sea urchin steroid production and elucidates the potential role of HSD genes in estrogen synthesis pathways, providing a foundation for further investigation of endocrine regulation in sea urchins.
This study evaluated the effects of dietary supplementation of hawthorn (Crataegus monogyna) berry (CMB) on growth performance, hematological parameters, antioxidant status, digestive enzyme activity, gut microbiota, and disease resistance of African catfish (Clarias gariepinus). A total of 600 fish were randomly assigned to four dietary treatments containing 0
Ciliates are promising first-feed organism for marine fish larvae because of their small size, nutritional value, and ease of culture. They can bridge the feeding gap until larvae are able to consume larger live prey. Intensive cultivation of ciliated protozoa under controlled conditions remains limited due to difficulties in maintaining high densities in steady cultures. This study evaluated the efficiency of different diets (BY – baker’s yeast Saccharomyces cerevisiae; RD – commercial rotifer diet; and RE – commercial rotifer enrichment product) and tested practical methods for supplying baker’s yeast and improve Euplotes sp. biomass production. Population density, specific growth rate (μ), and total ammonia nitrogen (TAN) were analysed using linear mixed models. Higher population densities growth were achieved with RD (31,386.0 cil mL⁻1) and BY (21,346.6 cil mL⁻1) than with RE (9142.3 cil mL⁻1) after seven consecutive days of cultivation. The RD supported continued population growth during 24-h feed-withdrawal, reaching the highest density (43,727 cil mL⁻1) on day 8. Feeding a fixed daily amount of baker’s yeast (0.4 g L⁻1 day⁻1) proved to be an effective alternative to density-based feeding. Specific growth rate was not affected by treatment in either experiment, although a significant temporal effect was detected in Experiment 2. Although high ammonia levels were observed during cultivation (33–60 mg L⁻1 NH3/NH4+), ciliate populations continued to increase without water renewal. These results demonstrate that short production cycles and simplified feeding strategies can support efficient Euplotes sp. cultivation. Further studies should investigate the effect of prolonged ammonia accumulation, the composition of the culture microbiota, and the nutritional profile of ciliates fed culture and enriched with different food sources.
Antimicrobial peptides (AMPs) have emerged as promising alternatives to antibiotics for controlling bacterial diseases in aquaculture because of their broad-spectrum antibacterial activity and low propensity for inducing antimicrobial resistance. In this study, a 14-amino-acid peptide (SRL14) was rationally designed from the C-terminal α-helical region of type I interferon h (IFNh) of Larimichthys crocea and subsequently optimized by amino acid substitution to generate the derivative peptide RRL14. The antibacterial activity, structural characteristics, physicochemical stability, cytotoxicity, hemolytic activity, antibacterial mechanism, and in vivo therapeutic efficacy of RRL14 were evaluated. RRL14 exhibited potent broad-spectrum antibacterial activity against both Gram-negative and Gram-positive bacteria, with a minimum inhibitory concentration (MIC) of 2 µM against Pseudomonas plecoglossicida. Time-kill assays demonstrated that RRL14 eliminated 99.9
Due to the global shortage and high price of fish meal, replacing fish meal with plant protein sources is essential for the sustainable development of aquaculture. However, plant protein substitution can exert a series of negative effects on cultured animals, including reduced feed intake and growth performance, and impaired intestinal health. Thus, it is necessary to actively explore nutritional strategies to alleviate these negative impacts. In this study, six experimental diets were formulated: a fish meal control diet containing 35
The present study assessed the effects of chitosan nanocapsules loaded with α-lipoic acid (NcLA) on the performance of Penaeus vannamei under nutritional stress induced by high soybean meal (SBM) content. The nanocapsules (with an average size of 183.4 nm) were prepared and incorporated into shrimp feed formulated to contain 44
Pacific white shrimp (Litopenaeus vannamei) raised in intensive aquaculture systems have semi-transparent bodies, small body sizes, and high levels of occlusion. These characteristics pose challenges for existing instance segmentation models, which are constrained by local receptive fields and high computational costs. Therefore, achieving both a lightweight architecture and high segmentation accuracy remains difficult. To address this challenge, we propose NCSSD-YOLO, a lightweight instance segmentation network based on non-causal state space duality. Built upon the YOLO11n-seg architecture, the model reconstructs the feature-processing pipeline from input representation to global modeling. First, the progressive feature extraction stem and fine-grained reorganization downsampling module preserve weak edges and high-frequency textures during input processing and scale transformation, thereby alleviating early feature degradation. Second, the core encoding unit, termed the non-causal duality block, incorporates a non-causal state space duality mechanism and two-dimensional rotary position embedding to model global dependencies and decouple spatial structures in densely populated scenes with linear computational complexity. Gating mechanisms are further used to suppress water-related noise. Experimental results show that NCSSD-YOLO achieves a Mask mAP50-95 of 0.666 and a mask recall of 0.940 with only 2.26 million parameters, corresponding to improvements of 2.5
The aquaculture of the sea cucumber Apostichopus japonicus is threatened by high temperature-induced skin ulceration in northern China. The present study compared the behavioral and physiological responses between ulcerated and non-ulcerated sea cucumbers at 32 °C, and evaluated the anti-ulceration advantages of reef-seeking behavior. Behavioral tests revealed a significantly lower reef-seeking tendency in ulcerated individuals compared to the non-ulcerated ones (P < 0.01), whereas righting, adhesion, and feeding behaviors did not differ significantly. Further, ulcerated sea cucumbers exhibited higher cortisol levels (P = 0.036), and exogenous cortisol injection significantly increased significanfly the ulceration rate (P = 0.018). These findings indicate that skin ulceration greatly impairs reef-seeking behavior, with cortisol mediating ulceration development. Compared to non-reef-seeking individuals, reef-seeking sea cucumbers developed significantly fewer ulcers (P = 0.001) and maintained significantly lower concentrations of cortisol (P = 0.032) and serotonin (5-HT) (P = 0.036). These findings indicate reef-seeking behavior enhances the ulcer resistance by regulating cortisol and 5-HT levels. Collectively, the present study showed that reef-seeking sea cucumbers had better behavioral and physiological traits under heat stress, and were with a markedly lower skin ulceration rate than non-reef-seeking individuals.
Accurate fish population estimates are essential for improving production efficiency and refined management in aquaculture. Although object detection algorithms are widely used for fish counting, they are often limited by fish overlapping, occlusion, and complex environmental conditions. In contrast, density estimation has gradually emerged as an effective approach due to its strong adaptability to varying environments. However, variations in fish size, high-density fish aggregation, and water turbidity pose substantial challenges to the counting accuracy. To tackle these challenges, this study proposes a density estimation model based on multi-scale semantic representations from different network depths. The MSSFNet incorporates three feature extraction modules, including a global feature extractor, a multi-scale feature extractor, and a local feature extractor, which collaboratively improve robustness to scale variation, dense aggregation, and complex background interference. In addition, we propose the Focal Distribution Matching Count Loss (FDMC Loss), which alleviates sample imbalance in density estimation. By down-weighting the contribution of easy samples during training and emphasizing harder ones, FDMC Loss improves sensitivity to irregular distributions and intricate regions, thereby producing more accurate density maps. The experimental results on a large-scale dataset containing 3131 images with approximately 364,000 annotated fish fry (116 fish fry per image on average) demonstrate the effectiveness of MSSFNet. On the test dataset, MSSFNet achieves a Mean Absolute Error of 6.65, Root Mean Square Error of 9.09, relative Root Mean Square Error of 0.085, and a coefficient of determination of 0.9855. Furthermore, deployment experiments on mobile platforms demonstrate the feasibility of MSSFNet for resource-constrained applications, highlighting its potential for practical aquaculture deployment. MSSFNet effectively reduces prediction errors and accurately captures the common features of targets across different scales and environments.
Understanding the effects of salinity on the physiological performance of Heliocidaris crassispina across its life history is imperative for aquaculture. This study investigated the survival, growth, and/or metabolism (oxygen consumption and ammonia excretion) of larval, juvenile, and adult H. crassispina at salinities ranging from 20 to 40. Larval survival and development peaked at an optimal salinity range of 32 to 36, whereas growth stagnated at 24 and lower. Juveniles exhibited optimal growth performance within a range of 28 to 32. They were highly sensitive to extreme salinity, exhibiting significant negative growth at salinities of 20 (− 0.07 ± 0.19
This study aimed to evaluate the effects of Hermetia illucens (black soldier fly) exuviae, as a chitin source (CHI), and lauric acid (LA) on the intestinal physiology of rainbow trout (Oncorhynchus mykiss). Four isoproteic and isolipidic semi-purified diets were tested: a control diet (CTRL), a diet with 1.5
Weight information is essential for grading, growth monitoring, biomass assessment, and harvest decision-making in abalone aquaculture. Image-based morphometric measurement reduces repeated weighing; however, geometric volume models based on external dimensions may retain residual errors due to individual shape variation. This study developed and evaluated interpretable regression models for estimating the weight of cultured abalone (Haliotis discus hannai) from image-based morphometric measurements, with a particular focus on the effect of a morphometric correction variable. After quality control based on measured density and morphometric consistency, 490 of 503 individuals were included in the final analysis. Semi-ellipsoid-based calculated volume (Cv) and a morphometric correction variable (Mc = Cv/PA, where PA is projected area) were calculated from total length, body width, thickness, and PA. Four regression models were evaluated using the same five-fold cross-validation scheme. Predictive performance was assessed using root mean square error (RMSE), mean absolute error (MAE), coefficient of determination (R2), and mean absolute percentage error (MAPE). The Cv-based linear model showed RMSE 4.18 g, MAE 3.20 g, R2 0.969, and MAPE 6.32
The larviculture of Steindachneridion spp. faces low survival rates due to early cannibalism. The literature indicates that the larviculture of this genus is complex due to high intraspecific aggressiveness influenced by factors such as luminosity and food density. Aiming to evaluate practical strategies, a 20-day experimental trial was conducted with "suruvi-bocudo" (S. scriptum) post-larvae (PL) in a completely randomized design (10 PL/L), testing three complementary diets (n = 5): exclusive brine shrimp (Artemia salina) nauplii (AT); Egg Yolk Powder + Artemia (EYP + A); and Milk Powder + Artemia (MP + A). Water parameters and daily mortality were monitored, with causes of death classified via stereomicroscope as with or without injuries. At the end of the experiment, the EYP + A treatment showed higher weight gain and final weight (p < 0.05), although there were no significant differences in survival and cannibalism rates among groups. Mortality was concentrated in the first five days, coinciding with the transition to exogenous feeding. The MP + A treatment had the lowest cannibalism rate in absolute numbers but the highest occurrence of deaths with injuries (p < 0.05). This suggests that a possible nutritional deficiency in this group may have hindered the completion of cannibalistic attacks, resulting in a higher occurrence of deaths with injuries. It is concluded that exclusive feeding with Artemia nauplii or supplementation with egg yolk powder are effective strategies for the initial development of the species, while milk powder proved inefficient in reducing mortality related to aggressiveness.
