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Cyanobacterial blooms (CBs) present significant challenges to Chinese mitten crab (CMC) culture, posing hazards to the aquatic microbial ecology. However, the current focus on the microbial ecological changes within the CMC culture system under the influence of CBs is somewhat insufficient. There’s an urgent need to analyze the microbial ecosystem of the CMC culture system under CBs. This study employed 16S rRNA gene amplicon sequencing to investigate the dynamics of the environmental microbial community in both the rice-crab co-culture (RC) and crab monoculture (CM) models. The results revealed that cyanobacteria reached high levels in the CM water in July, while they began to increase in the RC water in August. Notably, OTU147 (uncultured bacterium g_Planktothrix NIVA-CYA 15), identified as the dominant taxon associated with CBs, showed a significant linear relationship with TP, NO2−-N, and the N:P ratio. TP, TN, NO2−-N, and CODMn had a more pronounced impact on the structure of bacterial communities and cyanobacterial taxa in the water. The bacterial community structure involved in carbon metabolism displayed temporal succession in the water. The co-occurrence network of the bacterial community primarily consisted of Chloroflexi, Proteobacteria, and Firnicutes in the sediment, and Actinobacteria, Proteobacteria, Chloroflexi, and Bacteroidota in the water. In contrast, the co-occurrence network included different peripheral species in the sediment and water. Keystone species were predominantly represented by OTU22 (uncultured actinobacterium g_ hgcI clade) and OTU12 (uncultured Opitutae bacterium g_ norank) in the RC water, and by OTU25 (uncultured bacterium g_ Limnohabitans) in the CM water. TP, TN, NO2−-N, and CODMn were identified as the primary environmental factors influencing these keystone taxa within the culture water. In conclusion, this study on the microbial ecology of the CMC culture system under the influence of CBs provides valuable insights that can be instrumental in subsequent management efforts.

The Chinese mitten crab (Eriocheir sinensis) is an economically important crustacean. With the development of the E. sisnensis industry, precocity has become a significant challenge in juvenile crab culturing. In this study, the eyestalks of female E. sinensis from precocious (PE) and normal juvenile (NE) groups were used for proteome and metabolome analyses. In total, 731 up-regulated and 657 down-regulated differentially expressed proteins (DEPs) were identified in the PE and NE groups. In addition, 110 differentially expressed metabolites (DMs) were up-regulated and 256 were down-regulated in the PE group. An integrated analysis showed 5667 significant correlations between the metabolites and proteins and 109 common pathways in the proteome and metabolome. The proteins were mostly associated with the mechanistic target of rapamycin (mTOR) pathway, longevity regulation, autophagy, and the pyrimidine and purine metabolism pathways. The metabolites were primarily enriched in amino acid and lipid metabolisms. These results demonstrated the differences in the PE and NE groups at two omics levels and will be useful for the E. sinensis industry. [ABSTRACT FROM AUTHOR]

The Chinese mitten crab (Eriocheir sinensis), an economically important crustacean that is endemic to China, has recently experienced high-temperature stress. The high thermal tolerance of E. sinensis points to its promise in being highly productive in an aquacultural context. However, the mechanisms underlying its high thermal tolerance remain unknown. In this study, female E. sinensis that were heat exposed for 24 h at 38.5 °C and 33 °C were identified as high-temperature-stressed (HS) and normal-temperature-stressed (NS) groups, respectively. The hepatopancreas of E. sinensis from the HS and NS groups were used for transcriptome and proteomic analyses. A total of 2350 upregulated and 1081 downregulated differentially expressed genes (DEGs) were identified between the HS and NS groups. In addition, 126 differentially expressed proteins (DEPs) were upregulated and 35 were downregulated in the two groups. An integrated analysis showed that 2641 identified genes were correlated with their corresponding proteins, including 25 genes that were significantly differentially expressed between the two omics levels. Ten Gene Ontology terms were enriched in the DEGs and DEPs. A functional analysis revealed three common pathways that were significantly enriched in both DEGs and DEPs: fluid shear stress and atherosclerosis, leukocyte transendothelial migration, and thyroid hormone synthesis. Further analysis of the common pathways showed that MGST1, Act5C, HSP90AB1, and mys were overlapping genes at the transcriptome and proteome levels. These results demonstrate the differences between the HS and NS groups at the two omics levels and will be helpful in clarifying the mechanisms underlying the thermal tolerance of E. sinensis. [ABSTRACT FROM AUTHOR]

Objective: Fermented feed (FF) has several significant advantages in aquaculture. However, little is known about the characteristics of intestinal and environmental microbiota in the Chinese mitten crab Eriocheir sinensis. Methods: This study was conducted to elucidate the relationship between bacterial communities in the intestine of Chinese mitten crabs and the surrounding environment and to compare the bacterial communities in FF and non‐FF diet modes by using 16S ribosomal RNA high‐throughput sequencing technology. Result: Fermented feed diets mainly influenced the alpha diversity of intestinal microbiomes but could affect microbial community structures of beta diversity in water and sediment. Compared to water and sediment, crab intestines had the lowest operational taxonomic unit (OTU) richness and bacterial community diversity. The OTU richness and Chao richness index values were lower in the intestines of crabs that received FF than in crabs that were given non‐FF. No significant differences were observed in the bacterial diversity and OTU richness of water and sediment between the two feeding modes. The bacterial community structures were significantly different among the three environments. Tenericutes, Proteobacteria, and Actinobacteria were the most abundant phyla in the crab intestine, sediment, and water, respectively. Bacterial functions were also different among the three environments. Proportions of nitrate reduction and fermentation in the crab intestine, proportions of nitrification and sulfate respiration in the sediment, and proportions of chemoheterotrophy and aerobic chemoheterotrophy in the water were higher for the FF feeding mode than for the non‐FF mode. Conclusion: The bacterial community structures were significantly different among the three environments. The microbiome of the crab intestine was partially shared with that of the ambient environment. Additionally, the FF mainly influenced the alpha diversity of intestinal microbiomes but also affected the community structures of beta diversity in water and sediment. These results will help us to devise dietary strategies to influence the crab intestinal microbiota and provide guidance for sustainable crab culture practices. Impact statementAs a new type of feed, fermented feed mainly influenced the alpha diversity of intestinal microbiomes but also affected the community structures of beta diversity in water and sediment. [ABSTRACT FROM AUTHOR]

A linkage map was constructed using highmap software.5 In total, 7931 markers were mapped onto the genetic map in 26 linkage groups spanning 3008.26 cM with an average distance of 0.38 cM (Fig. High-density genetic map and QTL mapping for body color of the yellow catfish (Tachysurus fulvidraco × T. vachellii ) The hybrid yellow catfish ( I Tachysurus fulvidraco i × I Tachysurus vachellii i ), is an important economic species of freshwater fish in China.1 Because of the cross-incompatibility, the body color of hybrid F SB 1 sb has differentiated (Fig. [Extracted from the article]