Wensheng Li

The red-spotted grouper nervous necrosis virus (RGNNV) exhibits high pathogenicity in larval C. sonnerati, yet the immune molecular mechanism remains unclear. Non-coding RNAs (ncRNAs) are vital in the host’s immune responses during viral infection. However, there has been no study on ncRNA research for this species to date. We systematically identified 105 DE microRNAs (miRNAs), 157 DE long non-coding RNAs (lncRNAs) and 31 DE circular RNAs between the infection group and control group. Functional enrichment analysis revealed that these differentially expressed genes were significantly enriched in pathways associated with innate immune defense, inflammatory, and cell death, such as JAK-STAT signaling pathway, NF-κB signaling pathway, apoptosis, and necroptosis. Furthermore, the lncRNA–miRNA–mRNA interaction network involving miR-93 was constructed, which may represent a promising candidate therapy target for future investigations. This study presents the first comprehensive ncRNA transcriptome dataset of C. sonnerati infected with RGNNV, identifies key antiviral defense and cell death-related genes and hub pathways, and thereby identifies miR-93-involved lncRNA–miRNA–mRNA network and key targeted genes (STAT1, TRIM25, UNC93B, IL12RB1, IRF8, CDKN1A, FCGR1A) as hub molecular regulators in immune response of this species.

Benthic microbial communities are a vital component of coastal subtidal zones, playing an essential role in nutrient cycling and energy flow, and are fundamental to maintaining the stability and functioning of marine ecosystems. However, the response of benthic prokaryotic and eukaryotic microbial communities to environmental changes remains poorly understood. Herein, we conducted a nearly semimonthly annual sampling survey to investigate the temporal patterns and underlying mechanisms of benthic prokaryotic and eukaryotic microbial communities in the subtidal sediments of Sanshan Island, situated in the eastern Laizhou Bay of the Bohai Sea, China. The results showed that the temporal variations in benthic microbial communities followed a distinct seasonal pattern, with turnover playing a more dominant role in community succession. Nonetheless, contrasting temporal variations were observed in the alpha diversity of benthic prokaryotic and eukaryotic microbial communities, as well as in the dominant taxa across different microbial communities. Water temperature, dissolved oxygen, electrical conductivity, salinity, total nitrogen (TN), NH₄⁺, and PO₄³⁻ were identified as the predominant environmental drivers. The assembly of benthic microbial communities was driven by different ecological processes, in which stochastic processes mainly shaped the benthic prokaryotic communities, while deterministic processes dominated the assembly of benthic eukaryotic microbial communities. Interactions within benthic microbial communities were primarily characterized by mutualistic or cooperative relationships, but the ability of prokaryotic and eukaryotic microbial communities to maintain stability under environmental disturbances showed notable differences. These results shed light on the temporal dynamics and potential driving mechanisms of benthic prokaryotic and eukaryotic microbial communities under environmental disturbances, highlighting the distinct roles of prokaryotic and eukaryotic communities in coastal subtidal zones and providing valuable insights for the management and conservation of coastal subtidal marine ecosystems.

This study investigated the impacts of light spectra on oxidative stress and nutrient quality of the fish Plectropomus leopardus in indoor recirculating aquaculture systems. The fish (100 g ± 0.45 g [wet weight]) were cultures in five different light spectra (full-spectrum (400–800 nm), blue (450 nm), green (530 nm), red (630 nm), and dark) for 60 days. After experimentation, blood and muscle tissue were collected and analyzed for biochemical variables and nutritional quality. We demonstrated that the total cholesterol, triglycerides activities of P. leopardus in the dark groups were substantially elevated, relative to other groups (p < 0.05). Glutathione and glutathione peroxidase activities were elevated in the green light group versus other red groups, and cortisol was drastically reduced in the red group relative to other groups (p < 0.05). The crude ash concentration in the blue and full-spectrum group was substantially more elevated than in other groups (p < 0.05). Thr, Glu, Cys, Val, Met, Ile, Leu, Phe, Lys, His, Arg were markedly higher in the blue light versus the red light group (p < 0.05). The muscle of P. leopardus was rich in lysine and its essential AA index was in the order of blue light, full-spectrum, green light, dark and red group. The content of total saturated fatty acids in the blue light group was drastically lower relative to the dark, green and red groups (p < 0.05), and the total polyunsaturated fatty acids and DHA + EPA contents in the blue light group were substantially elevated relative to the other groups (p < 0.05). These results revealed that different light environments had certain effects on blood biochemical, antioxidant capacity, nutrient composition and proportion of P. leopardus. A comprehensive evaluation found that the blue light environment had more positive effects on the physiological, biochemical and nutritional quality of P. leopardus. This result provides a theoretical reference for the lighting strategy of an indoor recirculating aquaculture system.

As a new breed of grouper hybrid breeding, EFT has the advantages of delicious flesh, fast growth, and high deformity rate. We explored the metamorphosis and skeletal development of Epinephelus fuscoguttatus and hybrids (EFT) of E. fuscoguttatus () and E. tukula (). EFT grew slightly slower than E. fuscoguttatus during the larval period but grew faster during the juvenile period. The sequences of skeletal development were similar in EFT and E. fuscoguttatus. Newly hatched larvae did not have skeletons until 5days after hatching (DAH) when head cartilage started to develop and complete at 43days later. The vertebral column started to develop at 11DAH and was completed at 38DAH. Pectoral fin development began at 5DAH and ossification was completed at 48DAH in EFT and at 43DAH in E. fuscoguttatus. Anal fin development started at 11DAH and ossification was completed earlier in EFT than in E. fuscoguttatus. The caudal fins of the two groupers developed at 8DAH and ossified earlier in EFT than in E. fuscoguttatus. In contrast, E. fuscoguttatus had one additional epural than EFT. These results provide important basic biological data for the growth and skeletal development of pure and hybrid grouper.

Sex-specific DNA markers are very helpful for identifying genetic sex and studying sex determination mechanisms in fish. To identify the sex-specific markers of spotted knifejaw (Oplegnathus punctatus), we performed a comparative analysis of the female and male genomes. In this study, an 18 bp insertion was identified in the male genome after verification by sequencing depth and PCR. An effective and rapid method based on PCR was then developed to identify the genetic sex. A male-female-shared primer pair and a male-specific primer were designed for PCR amplification to avoid false-negative phenomena. To examine the primers in practice, we utilized hundreds of spotted knifejaw fish from different groups to identify their genetic sex, and the results were consistent with their phenotypic sex. The male-specific DNA marker would be helpful for artificial breeding, Y chromosome assembly and further study of the sex determination mechanism. This study is the first to identify an effective sex-specific marker in spotted knifejaw.