Salinity is a crucial environmental factor influencing the survival, growth, development, and reproduction of aquatic animals. However, the underlying molecular mechanisms of the shrimp’s response to salinity stress are not yet fully understood. Therefore, we used the Illumina NovaSeq 6000 platform to perform transcriptome sequencing of the hepatopancreas of Litopenaeus vannamei under high-salinity (30 PSU), medium-salinity (10 PSU), and low-salinity (0.5 PSU) conditions. We obtained 63.23 Gb of high-quality data and identified 3589 differentially expressed genes (DEGs), including 1638 upregulated and 1951 downregulated genes. Notably, a comparison between the control group (30 PSU) and the low-salinity group (0.5 PSU) revealed that the BBOX1 and CHE1 genes were significantly upregulated, while the ACOX1, MPV, CYP2L1, GCH, MVK, TREt1, and XDH genes were significantly downregulated. These genes are primarily involved in key metabolic pathways, such as fatty acid oxidation, cholesterol metabolism, and hormone synthesis and metabolism. The key genes involved in fatty acid β-oxidation, such as ACOX1, ACAD, HADH, HSD17B4, PECR, CROT, PIPOX, and CG5009, all showed a downward trend, suggesting that L. vannamei may respond to salt stress by regulating fatty acid oxidative metabolism, optimizing energy utilization, and maintaining cell homeostasis under low-salinity conditions. Functional annotation of gene ontology (GO) and KEGG pathway enrichment analysis highlighted the roles of these significant DEGs in the adaptation of L. vannamei to environments of varying salinity, underscoring the importance of metabolic pathways in their adaptive physiological responses. This study provides a crucial molecular biological basis for understanding the molecular mechanisms and physiological protection strategies of L. vannamei under salinity stress.

This study aimed to evaluate the quality and genetic diversity of farmed Litopenaeus vannamei across three distinct populations from Maoming City (MM), Zhanjiang City (ZJ), and Yangjiang City (YJ) in Guangdong Province. Muscle tissues from L. vannamei were analyzed for phenotypic traits, conventional nutrients, amino acids, and fatty acids, while genetic diversity was assessed using whole genome sequencing techniques. The analysis revealed that the crude protein content in shrimp across the three populations ranged from 20.87 to 21.95 g/100 g, crude fat content ranged from 0.90 to 1.50 g/100 g, essential amino acid content ranged from 5.55 to 5.86 g/100 g, total amino acid content ranged from 14.73 to 15.27 g/100 g, total fatty acid content ranged from 682.73 to 793.97 mg/100 g, total antioxidant capacity (T-AOC) ranged from 2.68 to 2.72 μmol/g, superoxide dismutase (SOD) activity ranged from 1021.97 to 1057.21 U/g, and catalase (CAT) activity ranged from 78.65 to 81.33 μmoL/min. No significant differences were observed in ash and crude fat levels among conventional nutrients, nor in the biochemical indexes T-AOC, CAT, and SOD. Genetic analysis showed that the single nucleotide polymorphism density (SNP/Kb) ranged from 15.323 to 17.461, nucleotide diversity (π) ranged from 2.98 × 10⁻⁵ to 15.84 × 10⁻⁵, polymorphism information content (PIC) ranged from 0.300 to 0.317, heterozygosity (Ho) ranged from 0.033 to 0.048, and inbreeding coefficients (FIS) ranged from 0.834 to 0.887. The genetic differentiation index (FST) values among the three populations ranged from 0.056 to 0.106. This study provides an evaluation of the germplasm resources and genetic diversity of farmed L. vannamei, offering insights for the efficient management and sustainable utilization of this species’ germplasm resources.

Fenneropenaeus merguiensis is one of the largest species of penaeid shrimp. It has a wide distribution of germplasm resources in the South China Sea and the southeastern coastal regions of China, yet its germplasm characteristics remain insufficiently understood. Therefore, we conducted analyses of basic nutritional components, amino acids, fatty acids, antioxidant indices, and genetic diversity in three F. merguiensis populations (FmRP, FmSZ, FmSY). The results showed a significant difference in ash content, with FmSZ having the highest ash content (1.77 g/100 g) (p < 0.05). A total of 17 amino acids were detected, and FmSZ exhibited higher concentrations of most amino acids, especially essential amino acids (p < 0.05). The analysis of fatty acid composition revealed significant differences between the populations, with FmSY potentially having a nutritional advantage overall (p < 0.05). In terms of antioxidant capacity and genetic diversity, there were no significant differences in total antioxidant capacity (T-AOC), catalase (CAT), or superoxide dismutase (SOD) among the populations (p > 0.05). However, genetic analysis indicated that FmSZ had the lowest inbreeding coefficient and relatively higher genetic diversity. In conclusion, among the three F. merguiensis populations, FmSZ has relatively higher nutritional quality and genetic diversity, and F. merguiensis is a high-quality aquatic product worth promoting. The analysis and characterization of various aspects of F. merguiensis from the three locations provide important information and data support for germplasm resources and genetic breeding efforts.

This study comprehensively evaluates the phenotypic traits, nutritional profiles, and genetic diversity of three cultured populations of Portunus pelagicus from Guangdong Province, China, namely from Shenzhen (PpSZ), Zhuhai (PpZH), and Chaozhou (PpCZ). We analyzed key nutritional components, including moisture, ash, crude fat, crude protein, total sugar, amino acids, and fatty acids. Notably, significant differences in total sugar content (p < 0.05) were observed among populations, whereas no substantial variation was detected in the other nutritional parameters. PpSZ exhibited significantly higher levels of specific amino acids, especially essential amino acids (p < 0.05). Fatty acid composition revealed a more favorable nutritional profile in PpZH. Analysis of physiological markers such as total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and catalase (CAT) activities demonstrated comparable levels across populations, with no significant differences. Genetic diversity assessment revealed SNP densities of 6.583, 6.16, and 6.08 SNPs/Kb for PpSZ, PpZH, and PpCZ, respectively. The low polymorphism (PIC < 0.25) indicates limited genetic variation within the species. This study provides valuable insights into the biochemical, nutritional, and genetic characteristics of these populations, offering critical implications for the optimization of aquaculture practices and the conservation of genetic resources for this economically significant species.