The giant freshwater prawn (GFP) is one of the most critical crustacean species cultured in Southeast Asia. Investigation of the genetic structure of current commercial stocks allows GFP breeding programs to better manage crosses and germplasm banks as well as to promote the rational use of GFP. The objective of the study was to characterize genetic diversity in diverse prawn populations with emphasis on those cultured in China. Seventeen microsatellite loci, including 12 novel loci derived from GFP transcriptome data, were screened to assess genetic diversity in one wild (Myanmar) and six cultured populations (i.e., four Chinese (Zhejiang, Guangxi, and Guangdong A and B), one Malaysian, and one Thai population). The results showed that the number of alleles per locus ranged from 3 to 18. The mean observed heterozygosity (0.363 ± 0.048) was less than the expected heterozygosity (0.637 ± 0.048). The mean values of polymorphism information content among the seven populations were >0.5 (ranging from 0.110 to 0.915). These cultured populations exhibited reduced genetic diversity when compared with that of the wild population. Pair-wise genetic differentiation ranged from 0.006 to 0.131 within the seven populations. The dendrogram of the genetic distance shows that the six cultured populations were distributed on the same major branch, suggesting that they have are genetically close, whereas the wild population was distributed on an independent branch. The results provide a basic assessment of genetic diversity in some available stocks and lay a foundation for future research efforts toward genetic monitoring and selective breeding.

Salinity is a crucial factor influencing the growth, development, immunity, and reproduction of aquatic organisms; however, little is known about the molecular mechanism of the response to salinity challenge in larvae of the giant freshwater prawn Macrobrachium rosenbergii. Herein, larvae cultured in three treatment groups with salinities of 10, 13, and 16‰ (S10, S13, and S16) were collected, and then transcriptome analysis was conducted by RNA-seq. A total of 6,473, 3,830 and 3,584 differentially expressed genes (DEGs) were identified in the S10 vs. S13 comparison, S10 vs. S16 comparison and S13 vs. S16 comparison, respectively. These genes are involved in osmoregulation, energy metabolism, molting, and the immune response. qPCR analysis was used to detect the expression patterns of 16 DEGs to verify the accuracy of the transcriptome data. Protein–protein interaction (PPI) analysis for DEGs and microsatellite marker screening were also conducted to reveal the molecular mechanism of salinity regulation. Together, our results will provide insight into the molecular genetic basis of adaptation to salinity challenge for larvae of M. rosenbergii.

The Asian giant soft-shelled turtle, Pelochelys cantorii (Trionychidae), is one of the largest aquatic turtles in China and was designated as a First-Grade Protected Animal in China in 1989. Previous investigation based on a combination of Illumina short-read, PacBio long-read and Hi-C scaffolding technologies acquired a high-quality chromosome-level genome of Pc. cantorii. In this study, comparative genomic analysis between Pc. cantorii and 16 other vertebrate genomes indicated that turtles separated from the ancestor of archosaurians approximately 256.6 (95% highest posterior density interval, 263.6–251.9) million years ago (Mya) (Upper Permian to Triassic) and that Pc. cantorii separated from the ancestor of Pd. sinensis and R. swinhoei approximately 59.3 (95% highest posterior density interval, 64.3–54.3) Mya. Moreover, several candidate genes, such as VWA5A, ABCG2, A2M and IGSF1, associated with tumor suppression, growth and age were expanded, implicating their potential roles in the exceptional longevity of turtles. This new chromosome-level assembly has important scientific value in the study of conservation of Pc. cantorii and also enriches the evolutionary investigation of turtle species.

The spectrum is a key environmental factor, and light‐emitting diodes (LEDs) can influence the growth and development of crustaceans by altering the composition of the spectrum. This study conducted a 30‐day experiment to investigate the effects of five LED spectra (red, yellow, blue, green, and white light) on the growth, antioxidant and immune enzyme activities, stress hormone levels, and the expression of α‐amylase (α-AMY), ecdysone receptor (EcR) and retinoid X receptor (RXR) genes in juvenile redclaw crayfish (Cherax quadricarinatus). The results show that the survival rate of juveniles is markedly higher in the yellow and red‐light groups than in the other three groups (P < 0.05). The green light group exhibits the lowest survival rate, yet it demonstrates the highest weight gain rate and specific growth rate. Regarding enzyme activity and hormone levels, the yellow light group shows the lowest malondialdehyde content, with higher superoxide dismutase and acid phosphatase activity than the other groups; no significant differences are observed in lysozyme activity among the groups (P > 0.05). The melatonin content in the green and blue light groups is significantly higher than that in the other three groups (P < 0.01). In terms of growth gene expression, the expression of α-AMY, EcR, and RXR in juvenile C. quadricarinatus is regulated by the spectrum. In conclusion, when raised under the yellow light spectrum, juvenile C. quadricarinatus displays elevated survival rates, rapid growth, and robust antioxidant and immune defenses. This study provides important technical parameters for optimizing and enhancing the industrial cultivation of juvenile C. quadricarinatus.