Search Results (106)

The Chinese mitten crab (Eriocheir sinensis), as an aquatic food with high economic value, is favored by consumers for its high nutritional value and unique flavor. Its physiological status during temporary rearing and live transportation determines changes in meat quality, nutrition, flavor and food safety. Environmental stresses during this process are prone to inducing physiological disturbances in the crabs, resulting in reduced survival rates and degraded product quality. This paper systematically reviews the impacts of four pivotal environmental factors, namely dissolved oxygen (DO) levels, ambient temperature, water salinity, and ammonia nitrogen concentration, on the survival performance and quality maintenance of E. sinensis during temporary holding and live transport. It comprehensively clarifies the mechanisms through which fluctuations in these factors elicit physiological stress, oxidative damage, and metabolic disorders in the crabs while evaluating effective mitigation strategies such as gradient cooling and precise water quality regulation. In addition, key research gaps in the field are identified, including the lack of real-time vitality monitoring technologies and species-specific standardized transportation protocols, and future directions involving the integration of sensor technologies and adaptive environmental regulation are proposed. In summary, the survival status and quality of E. sinensis during temporary rearing and live transportation are synergistically regulated by various environmental factors. Developing scientific strategies can effectively mitigate the adverse effects of environmental stress, ensure food safety, and provide a theoretical basis for the live preservation, processing, and transportation of aquatic products. Full article

Fine-grained monitoring of aquatic vegetation in crab ponds is essential for regulating water quality, sustaining ecological balance, and optimizing Chinese mitten crab (Eriocheir sinensis) aquaculture. However, owing to the complex water environment, fragmented vegetation morphology, and the absence of dedicated annotated datasets, traditional remote sensing techniques struggle to achieve highly accurate semantic segmentation and classification. In this study, we construct the first unmanned aerial vehicle (UAV) multispectral dataset for crab pond aquatic vegetation, encompassing four species, Alternanthera philoxeroides, Vallisneria natans, Hydrilla verticillata, and Elodea nuttallii, with pixel-level annotations verified by field surveys across typical aquaculture sites in Jiangsu Province, China. Furthermore, we introduce the Multi-scale Frequency–Spatial Collaborative Network (MFSCNet), built upon a MedNeXt backbone and augmented with distributed modules, including Channel Reduction Attention, Spatial Frequency Selection, a spatial–frequency fusion module, and Mobile Graph Convolution that operate cooperatively across the encoder, skip connections, decoder, and output head. This design suppresses complex water-background interference, enhances vegetation texture representation, and preserves the spatial continuity of vegetation patches. Experimental results demonstrate that, with a lightweight parameter size of merely 19.38 M, MFSCNet achieves a remarkable mean Intersection over Union (mIoU) of 0.9044, outperforming various mainstream convolutional neural network (CNN) and Transformer-based architectures. This study not only provides a high-precision remote sensing technical framework for the accurate multi-class identification and quantitative assessment of aquatic vegetation in crab ponds but also establishes reliable data support for refined aquaculture management and aquatic ecological conservation. Full article

This study investigated the effects of choline on endogenous phospholipid synthesis in Chinese mitten crab (Eriocheir sinensis). Chinese mitten crabs (0.40 ± 0.03 g) were fed diets supplemented with 0%, 0.2% or 0.4% choline under low phospholipids (low-PL) or normal phospholipids (normal-PL) for eight weeks. The results showed that feeding the Chinese mitten crab with 0.4% choline in low-PL diets up-regulated significantly the relative mRNA expressions of neuropathy target enzyme 1 (nte1), phospholipase A2 (pla2) and phospholipase B (plb). Moreover, the crabs fed the 0.4% diet at low-PL diets enhanced hepatopancreatic fatty acid binding protein 3 (fabp3), fatty acid transporter protein 4 (fatp4), carnitine palmitoyltransferase-2 (cpt-2), carnitine acetyltransferase (caat), carnitine palmitoyltransferase-1a (cpt-1a) and carnitine palmitoyltransferase-1b (cpt-1b). However, feeding the mitten crabs 0.2% choline in the normal-PL diets diets up-regulated significantly the relative mRNA expressions of nte1, pla2 and plb. These results indicate that 0.4% choline up-regulates the expressions of genes involving in phospholipids synthesis of Chinese mitten crab fed with low-PL diets, while 0.2% choline improved the genes involved in phospholipid decomposition under normal-PL conditions. Full article

Hepatospora eriocheir is a microsporidian parasite of the Chinese mitten crab Eriocheir sinensis, an invasive decapod now widely distributed in European inland and coastal waters. Although the host is common across much of Europe, confirmed European records of H. eriocheir have remained scarce and, until now, have not included the Baltic Sea region. In this study, 15 adult E. sinensis collected from the Vistula Lagoon, southern Baltic Sea, were examined using gross pathological assessment, wet-mount microscopy, histopathology, PCR amplification, Sanger sequencing, and phylogenetic analyses of parasite SSU rRNA and host COI sequences. Hepatopancreatic alterations were observed in several individuals, ranging from pale discolouration and friability to loss of normal tissue organisation. Spores were detected in fresh squash preparations from affected tissue, and histology revealed epithelial disruption, intratubular spore accumulation, and necrotic changes consistent with progressive microsporidian infection. Molecular screening confirmed H. eriocheir in 60.0% of crabs, with positive cases occurring in both females and males. The parasite sequences formed a single, well-supported clade and were highly similar to previously reported H. eriocheir sequences from the United Kingdom and China. Host COI sequences represented three mitochondrial haplotypes, indicating that the infection occurred across more than one host mitochondrial haplotype background. These findings constitute the first record of H. eriocheir in E. sinensis from the Baltic Sea and support the hypothesis that infected crabs reaching the Vistula Lagoon are connected with the wider North Sea invasion system rather than an isolated Baltic lineage. Full article

Massilia varians has potential as a probiotic to inhibit bacterial pathogens in aquaculture, but very limited information is available regarding its use in Chinese mitten crab Eriocheir sinensis for enhancing host immunity, antioxidant ability and intestinal microbiota homeostasis. In this study, a 40-day feeding trial was conducted to evaluate the protective effects of dietary supplementation with M. varians P2-4 on nonspecific immune response, antioxidant status, intestinal microbiota and resistance against Pseudomonas aeruginosa infection in E. sinensis. Results demonstrated that dietary supplementation with M. varians P2-4 at 6.0 × 10⁶ to 6.0 × 10⁸ CFU/g diet significantly boosted nonspecific immunity and improved antioxidant capability of E. sinensis, mainly as evidenced by markedly increased activities of plasma lysozyme, plasma superoxide dismutase, hepatopancreatic superoxide dismutase and catalase. Furthermore, crabs fed M. varians P2-4-supplemented diets exhibited markedly improvements in intestinal microbiota composition and diversity, and showed substantially enhanced survival following P. aeruginosa challenge, with 7-day relative percentage survival ranging from 76.9% to 100.0%. To the best of our knowledge, this is the first study to reveal that M. varians P2-4 supplementation functions as a new biocontrol strategy in E. sinensis by effectively improving the non-specific immunity, antioxidant status and intestinal microbiota to mitigate P. aeruginosa infection. Full article

Monosex culture has been shown to enhance farming productivity in several decapod crustaceans, and it has also been suggested that this approach holds high potential for the sustainable aquaculture of the Chinese mitten crab, Eriocheir sinensis. Pronounced sexual dimorphism in E. sinensis facilitates the implementation of a monosex culture. This study aimed to compare the growth, gonadal development, culture performance, and economic outcomes of two monosex culture modes, i.e., an all-female culture and an all-male culture, as well as a mixed-sex culture (males: females = 1:1) during an 8-month growth period in earthen ponds. The results showed that: (1) Throughout the grow-out period, the average body weight in both monosex culture treatments was consistently higher than in the mixed-sex treatment, with a significantly greater body weight in the all-female and all-male treatments than that of males and females in the mixed-sex treatment being detected during mid-June and October, respectively (p < 0.05). (2) The percentages of both sexes that had finished puberty molting were mostly similar between the monosex and mixed-sex treatments between July 20th to October 10th, although the all-female treatment had a significantly lower puberty molting percentage than the mixed-sex treatment on August 10th (p < 0.05). Gonadosomatic index (GSI) values were similar between the monosex and mixed-sex treatments for both males and females (p > 0.05). (3) At harvest period, the final body weight in the all-male treatment was significantly higher than that of the mixed-sex treatment (p < 0.05). In contrast, the all-female treatment exhibited a significantly higher survival rate and a lower limb injury rate compared with the mixed-sex treatment (p < 0.05). As a result, the yield of the all-male and all-female treatments exceeded that of the males and females in the mixed-sex treatment by 24% and 13%, respectively. Additionally, the mixed-sex treatment also had a significantly higher feed conversion ratio (p < 0.05). Finally, the monosex treatments had a higher proportion of large crabs (males ≥ 200 g, females ≥ 175 g) and a lower proportion of small crabs (males ≤ 150 g, females ≤ 100 g) compared to the mixed-sex treatment. (4) In terms of economic benefits, net profit and return on investment (ROI) were highest under the all-female treatment, while the mixed-sex treatment recorded the lowest total return, net profit, and ROI (p < 0.05). In conclusion, an all-female culture is recommended for the grow-out culture period of E. sinensis, as it led to a higher survival rate, produced larger-sized crabs and generated greater overall economic benefit. Full article

The Chinese mitten crab (Eriocheir sinensis) is widely distributed along eastern China, where northern and southern populations may have evolved different environmental adaptation mechanisms. DNA methylation, as an important epigenetic modification, plays a key regulatory role in environmental adaptation. In this study, muscle and hepatopancreas tissues from E. sinensis populations of the Liaohe River (LH) and Beilunhe River (BLH) were subjected to integrated RNA-seq and whole-genome bisulfite sequencing (WGBS) analyses, generating 12 mRNA libraries and 12 DNA methylation libraries. RNA-seq analysis identified 622 and 783 differentially expressed genes (DEGs) in muscle and the hepatopancreas, respectively, in the LH group compared with the BLH group, with downregulated genes accounting for a larger proportion. WGBS analysis showed that genome-wide DNA methylation in E. sinensis was predominantly in the CG context, with the highest methylation levels observed in gene body regions. A total of 972 and 991 differentially methylated regions (DMRs) were identified in muscle and the hepatopancreas, respectively. Integrated analysis further identified 10 differentially methylated and expressed genes (DMEGs) in muscle and 26 DMEGs in the hepatopancreas. Notably, no single fixed pattern was observed between methylation changes and gene expression changes in either tissue. These findings suggest that DNA methylation may participate in environmental adaptation in northern and southern populations of E. sinensis by modulating gene expression. Our results highlight the important role of epigenetic regulation in the evolutionary adaptation of crustaceans to different environments and provide a theoretical basis for the development of environment-associated molecular markers and the evaluation of adaptive germplasm resources. Full article

Dietary lipid sources critically influence growth, health, and muscle quality in Chinese mitten crab (Eriocheir sinensis), yet how high oleic acid diet (HOA) regulates intramuscular nutrient deposition remains unclear. Here, a 10-week feeding trial compared isonitrogenous and isoenergetic diets, in which soybean oil was replaced with high-oleic peanut oil. HOA significantly improved weight gain, specific growth rate, and protein efficiency ratio, without affecting survival, hepatosomatic index (HSI), or gonadosomatic index (GSI). HOA enhanced antioxidant capacity by increasing catalase activity and reducing malondialdehyde, while key non-specific immune enzymes were unchanged. In muscle, HOA did not increase intramuscular oleic acid (OA) content but reduced linoleic acid and upregulated genes involved in fatty acid transport and β-oxidation. HOA also shifted free amino acids (higher glutamate and lysine; lower proline) without significant transcriptional upregulation of the mechanistic target of rapamycin (mTOR) pathway or changing total protein. Multi-omics analyses indicated altered nucleotide/purine pathways and pronounced glycerophospholipid remodeling, identifying discriminatory lipid species. Overall, oleic-acid-rich lipids promote growth and antioxidant defense while reprogramming muscle lipid metabolism, supporting their targeted use to optimize crab muscle quality. Full article

The fungal pathogen Metschnikowia bicuspidata causes “milky disease” in the Chinese mitten crab (Eriocheir sinensis), which poses substantial challenges to sustainable aquaculture development considering the current lack of effective treatment interventions. To address this issue, in laboratory validation, we developed two rapid recombinase polymerase amplification (RPA) detection methods for M. bicuspidata in E. sinensis targeting the histone acetyltransferase B-type subunit 2 gene (HAT-B2): an electrophoretic assay (RPA-AGE) and a colloidal gold lateral flow dipstick assay (RPA-LFD). We optimized RPA-AGE and RPA-LFD protocols for specific pathogen detection. Target detection was achieved within 35 min using RPA-AGE (30 min amplification at 37 °C followed by 5 min agarose gel electrophoresis), whereas RPA-LFD provided results in 15 min with high specificity (10 min amplification at 37 °C plus 5 min strip reading). Both methods exhibited exclusive specificity to M. bicuspidata, with no cross-reactivity with six pathogens, including Escherichia coli, Staphylococcus aureus, Aeromonas hydrophila, Candida albicans, Saccharomyces cerevisiae, and Microsporidia sp. The detection sensitivity of both platforms reached 4.8 copies/μL in laboratory validation. For field testing, the detection results from 30 field samples showed that although the 70% detection rate was lower than the 83.3% achieved by quantitative PCR, these approaches surpassed the detection rate of conventional PCR (53.3%). Notably, the RPA-LFD platform is applicable under field conditions as no specialized equipment is required. These rapid, sensitive, and specific detection systems provide practical tools for the early diagnosis and containment of M. bicuspidata infections in aquaculture settings. Full article

“Milky disease” of the Chinese mitten crab (Eriocheir sinensis), caused by Metschnikowia bicuspidata, leads to substantial economic losses. Despite extensive research on its pathogenesis, the genetic basis of host resistance and underlying regulatory mechanisms remain unclear, limiting the development of disease-resistant varieties. This study aimed to (1) evaluate resistance differences among 10 E. sinensis families (five highly resistant and five sensitive) via artificial challenge; (2) identify disease-resistance-associated genetic loci using genome-wide association analysis (GWAS). Our findings revealed that the F05 family exhibited the strongest resistance, with a mortality rate of only 3% and a molting rate of 73%, accompanied by superior growth performance. Whole-genome resequencing identified 10,161,545 high-quality SNPs, and GWAS detected 767 loci significantly associated with disease-resistance traits, among which two pleiotropic SNPs (Chr46:18395778 and Chr1:20680490) were simultaneously associated with both “dead or not” and “qPCR fixed amount of fungi”, reflecting their functional relevance in regulating survival and pathogen load. Notably, we propose for the first time that E. sinensis achieves resistance by inducing M. bicuspidata into a viable but nonculturable (VBNC) state, in which the fungal cells remain metabolically active but cannot form colonies on conventional culture media. This study establishes a multidimensional resistance evaluation system, clarifies the genetic basis and novel mechanism of resistance, and provides valuable molecular markers for marker-assisted breeding. The findings contribute to reducing disease-related losses and promoting sustainable development of the E. sinensis aquaculture industry. Full article

Oxidative stress represents a critical threat to aquatic animal health and aquaculture productivity. Allicin, a natural plant extract, has not been systematically investigated for its antioxidant mechanisms in aquatic crustaceans. This study established in vitro and in vivo models of tert-butyl hydroperoxide (T-BHP)-induced oxidative stress in Chinese mitten crabs (Eriocheir sinensis) to evaluate the hepatoprotective effects of allicin. Integrating biochemical, transcriptomic, and ultrastructural analyses, we found that allicin significantly alleviated T-BHP-induced cytotoxicity and oxidative damage in vitro. Mechanistically, allicin up-regulated antioxidant genes including glutathione peroxidase (gpx) and thioredoxin reductase 1 (trxr1), and down-regulated pro-inflammatory cytokines such as interleukin-1 beta (il-1β), suggesting the concomitant activation of the Nrf2 signaling pathway and inhibition of the p38-MAPK/NF-κB pathway. Transcriptomics further indicated its role in restoring proteostasis and mitochondrial function. A 35-day feeding trial validated these findings in vivo; dietary supplementation with 300 mg·kg⁻¹ allicin effectively reversed T-BHP-induced disturbances in antioxidant enzyme activities and immune-related gene expression. These consistent findings demonstrate that allicin alleviates hepatopancreatic oxidative damage through multi-pathway synergism, supporting its potential as a green and effective antioxidant feed additive in aquaculture. Full article

Molting is a critical physiological process for the growth and development of Eriocheir sinensis. Any disruption in this process can significantly affect both survival rates and crab quality. The regulatory mechanisms of molting vary across different stages of the molting cycle and remain poorly understood. In this study, ATAC-seq and RNA-seq were combined to identify the integrated differentially expressed genes (IDEGs) in muscle across adjacent stages of the molting cycle. A total of 17, 491, 84, and 491 IDEGs were identified in the comparisons of inter-molt_vs_pre-molt, pre-molt_vs_molt, molt_vs_post-molt, and post-molt_vs_inter-molt stages, respectively. GO enrichment analysis of these IDEGs revealed several key signaling pathways involved in each adjacent molting stage. The GPCR signaling, steroid hormone-mediated signaling, and smoothened signaling pathways were all active across three molting transitions (pre-molt_vs_molt, molt_vs_post-molt, and post-molt_vs_inter-molt). Among them, the GPCR pathway played a dominant role throughout the process. Further structural analysis and RT-qPCR validation identified eight GPCRs involved in molting regulation: GRM7 and moody were specific to the post-molt_vs_inter-molt stage; Kpna6, ADRB2, and SSTR2 were unique to the pre-molt_vs_molt stage; FMRFaR and gpr161 functioned in both post-molt_vs_inter-molt and pre-molt_vs_molt stages; and mth2 was active in both post-molt_vs_inter-molt and molt_vs_post-molt stages. These findings improve the understanding of molting regulation and provide potential targets for further genetic improvement in E. sinensis. Full article

As an important economic aquatic product in China, the farming method of Eriocheir sinensis significantly impacts its quality and physiological metabolism. In this study, the effects of lake (LK) farm and pond (PD) farm on the gene expression profiles and metabolic pathways in E. sinensis were evaluated by integrating transcriptomic and metabolomic analyses. A total of 812 differentially expressed genes (DEGs) were identified in the hepatopancreas of crabs. The DEGs were mainly enriched in nutrient reservoir activity, regulation of response to oxidative stress, and lipid transporter activity. In addition, LC-MS analysis identified 410 significantly differential metabolites, and KEGG pathway enrichment showed that these metabolites were mainly enriched in the MAPK signaling pathway, HIF-1 signaling pathway, and glycerolipid metabolism. Integrated transcriptomic and metabolomic analyses revealed that the AMPK signaling pathway, cytochrome P450-mediated xenobiotic metabolism, glycerophospholipid metabolism, and the apoptosis signaling pathway collectively exert a significant influence on the growth performance of crabs. Collectively, our findings demonstrated that the crabs in the LK group exhibit enhanced antioxidant and detoxification capacities, concomitant with reduced protein synthesis and energy metabolism, and underwent increased apoptotic events. The finding of this study will provide valuable and novel insight into crab farming practices in different aquaculture environments, providing theoretical foundations for optimizing ecological aquaculture models in Datong Lakes’ crab farms. Specifically, combined supplementation with natural feed organisms and mechanical aeration may effectively mitigate benthic hypoxia and nutritional deficits, thereby promoting sustainable production in the lake-based culture of crabs. Full article

Feeding Chinese mitten crabs with fresh-frozen fish causes nutritional imbalance and increases disease risk. Compound feed offers better nutrient balance but still requires improvements in palatability and growth performance. This study evaluated the effects of replacing fresh-frozen fish with glutamine dipeptide-supplemented formulated diet on growth, hepatopancreas health, and edible quality, aiming to inform feed formulation strategies. A five-month feeding trial (June–October) was conducted with two treatments: the experimental group received only glutamine dipeptide compound feed, while the control group was fed a mix of fresh-frozen fish and compound feed. Crabs in the experimental group showed significantly higher body weight, length, and width. No significant differences were found in the hepatopancreatic index, gonadosomatic index, meat yield, or total edible yield. In October, the experimental group showed lower malondialdehyde (MDA) levels in the hepatopancreas and higher alkaline phosphatase (AKP) and acid phosphatase (ACP) activities in males. In females, hemolymph AKP and ACP were higher in the control, while glutamic pyruvic transaminase (GPT) was higher in the experimental group. Whether this is related to a potential risk of liver damage or a reaction at a special stage remains to be further verified. Digestive enzyme activities (protease, lipase, amylase) were generally higher in the experimental group, particularly in August (p < 0.05). In October, protease activity in females and lipase activity in males were significantly higher than in controls (p < 0.05). Nitrogen and phosphorus retention in muscle was also significantly higher, indicating better nutrient utilization (p < 0.05). Overall, these findings indicate that a glutamine dipeptide-supplemented diet provides a more effective and sustainable alternative to fresh-frozen fish over a five-month rearing period, improving digestive physiology, feed efficiency, growth performance, and edible quality and flavor. Full article

The Chinese mitten crab (Eriocheir sinensis) from Yangcheng Lake is a globally renowned geographical indication product. To characterize changes in stable isotopic signatures in this species in Yangcheng Lake during the year-round culture period, this study investigated the dynamic changes in stable isotopic fingerprints (δ¹³C, δ¹⁵N, δ²H and δ¹⁸O) of the third pereiopod across an annual aquaculture cycle. Isotopic ratios were analyzed via one-way ANOVA, principal component analysis (PCA), linear discriminant analysis (LDA) and Pearson correlation analysis. Results demonstrated that δ¹³C stabilized after six months of cultivation, showing no significant temporal variation (p > 0.05). Multivariate statistical analysis further revealed that the samples cultured in the initial period could be clearly differentiated in both PCA and LDA plots. However, after six months, the monthly sample points became highly overlapping and indistinguishable, indicating that the crabs had developed stable and consistent isotopic “fingerprints” by that time. Pearson correlation analysis indicated significant correlations among all other isotope pairs, with the exception of δ¹⁵N and δ²H. This study confirms that isotopic signatures require prolonged cultivation (≥6 months) to reflect authentic geographical traits. In addition, our findings provide a basis for verifying the origin of Chinese mitten crab and other aquatic taxa in Yangcheng Lake. Full article