The Neptunea cumingii (N. cumingii) fishing industry has long relied on expensive and perishable skate (Raja porosa) meat as bait. The unknown chemical attraction mechanism has hindered the development of artificial alternatives. This study employed untargeted metabolomics to analyze the chemical composition of skate meat and combined quantitative behavioral analysis to identify four key attractant compounds. These compounds were taurine, glutamate (Glu), inositol, and lactate. A standardized behavioral assessment system was established using the three parameters of response time, displacement distance, and movement velocity. This system enabled precise quantification of attraction efficacy. Concentration-gradient experiments determined the optimal concentration for all four compounds as 0.1 M. Taurine exhibited the strongest single-compound activity. It reduced response time by 50% and increased displacement distance by 164.5%. The mixture of four compounds at 0.1 M produced significant synergistic effects. The mixture achieved a comprehensive score of 93.6. This score approached that of natural skate meat at 94.8. All behavioral parameters improved by over 69% compared to the best single compound. These findings reveal the key attractant components in skate meat. They provide a scientific basis for developing efficient and stable artificial attractants. This research holds substantial value for promoting sustainable development of the N. cumingii fishing industry.

Water exchange capacity is critical for maintaining marine environmental quality and supporting the sustainable development of aquaculture. This study applies a high-resolution three-dimensional FVCOM hydrodynamic model coupled with the DYE-RELEASE module. The model was validated against tidal, current, and thermohaline observations. Water residence time (Tre) was used as the primary evaluation metric, supplemented by analyses of residual circulation, material diffusion, and regional variability, to systematically quantify the water exchange mechanisms and seasonal variations in the coastal waters of Changhai County under the combined influence of tides, wind forcing, and thermohaline conditions. Results show that overall residual currents in Changhai County are weak (average velocity: 0.032 m s⁻¹). However, local circulations and stagnation zones frequently develop near islands and channels, strongly influencing material diffusion. In summer, water exchange is primarily controlled by thermohaline effects, which strengthen density stratification, suppress vertical mixing, and modify circulation patterns, thereby reducing the efficiency of tide-driven exchange. Water exchange is weakest near Guanglu Island (46.6–48.6 d) and strongest near Haiyang Island (13–14 d). In winter, wind forcing dominates, enhancing vertical mixing and accelerating water renewal. Residence time in the Changshan Archipelago–Guanglu Island region decreases by 30–50% compared with summer. Overall, winter water renewal is 15–25% more efficient than in summer. This study demonstrates that water exchange in Changhai County is regulated by the combined effects of tides, wind forcing, and thermohaline dynamics. The identified spatial heterogeneity and seasonal characteristics provide a scientific basis for optimizing aquaculture planning and mitigating marine environmental risks.

This study was designed to evaluate the genetic parameters of growth, meat yield and foot color in Pacific abalone (Haliotis discus hannai) to support the development of a quality-oriented breeding program. Using data from 141 pedigreed full-sib families, heritabilities and genetic correlations among these traits were estimated. The results indicated that shell length at varying ages (0.45–0.71) and total wet weight (0.48) exhibited moderate-to-high heritabilities, suggesting substantial potential for genetic improvement in growth traits. The heritabilities for foot color (0.26) and meat weight (0.31) were moderate and statistically significant (p < 0.05), whereas the heritability for meat yield (0.14) was low and not statistically significant (p > 0.05). Strong positive genetic correlations were observed between shell length and total wet weight at harvest (0.90), as well as between total wet weight and meat weight at harvest (0.92). In contrast, the genetic correlations between total wet weight and foot color, and between total wet weight and meat yield, were low and not statistically significant (p > 0.05). These findings suggest that direct selection can effectively improve the growth and meat weight of Pacific abalone. However, improving foot color and meat yield may require independent or multi-trait selection approaches. Overall, this study provides crucial data for formulating a comprehensive breeding strategy that integrates both production efficiency and product quality in Pacific abalone aquaculture.

Sea surface temperature (SST) anomalies represent a critical threat to the operational safety and productivity of marine ranching systems. Taking a typical marine ranching area in the Northern Yellow Sea as the study area, this study developed a lightweight two-stage field-to-site forecasting framework. In the first stage, a Convolutional Long Short-Term Memory network (ConvLSTM) was employed to generate 1–5 days regional SST forecasts. Through experiments involving 24 input configurations, the combination of Optimum Interpolation Sea Surface Temperature (OISST), seasonal and trend components, and ERA5 meteorological variables was identified as an optimal configuration, providing spatial-evolution constraints for the target location. In the second stage, the 5-day target-site forecasts were concatenated with OISST to construct a 60-day sequence, which was then used to drive a lightweight Gated Recurrent Unit (GRU) for extended forecasts from days 6 to 15. This strategy reformulates the forecasting task into a spatially constrained 10-day extension forecast, thereby suppressing long-lead error accumulation. The results showed that, in the regional forecasting stage, an RMSE of 0.83 °C and MAE of 0.63 °C were achieved on Day 5, while in the extended-forecasting stage, an RMSE of 0.89 °C and MAE of 0.69 °C were achieved on Day 15. Compared with single-stage ConvLSTM and GRU models performing direct 15-day forecasting, the field-to-site strategy reduced RMSE by approximately 25.21% and 9.18%, respectively, and reduced MAE by approximately 24.18% and 8.00%, respectively. Independent validation against in situ buoy observations further showed that the proposed framework introduced only limited additional errors comparable to the inherent discrepancy between OISST and buoy observations. Additional tests under representative marine heatwave (MHW) conditions showed that the framework retained useful forecasting skill under anomalous warming conditions. Furthermore, its extended application experiments at five additional marine ranching sites in the Northern Yellow Sea produced consistent forecasting performance, with mean RMSE and MAE ranging from 0.71 °C to 0.75 °C and from 0.53 °C to 0.56 °C, respectively. The proposed method can therefore provide a risk-warning window of at least two weeks for marine ranching management and support timely operational decisions for temperature-related risk mitigation and refined aquaculture management.

Heat stress causes severe oxidative damage and immune cell death in marine bivalves, but its upstream regulators remain unclear. This study identified regulators linking heat stress to oxidative damage in Pacific oyster haemocytes. Under 30 °C exposure, the apoptosis rate of oyster haemocytes increased from ~4.54% to 17.40% at 24 h, accompanied by elevated ROS, malondialdehyde, and lipid hydroperoxide and reduced SOD activity. GSEA and protein interaction analysis of the haemocyte transcriptome pinpointed protein disulfide isomerase A6 (CgPDIA6) as the hub gene linking endoplasmic reticulum stress, apoptosis, and oxidative stress. Single-cell in silico knockout placed CgPDIA6 at the head of a coupled SOD–peroxiredoxin relay (CgSOD1, CgSOD2, CgPRDX6) and shifted haemocytes toward a stress-activated state. This prediction was confirmed by RNAi knockdown, in which silencing CgPDIA6 aggravated heat-induced oxidative injury, reduced the expression of antioxidant-related genes (CgSOD1, CgSOD2, and CgPRDX6), and further suppressed SOD activity. Molecular dynamics simulations showed that heat destabilized its catalytic thioredoxin domains, compromising its protective function. These results demonstrate that CgPDIA6 protects haemocytes against heat-induced oxidative damage by sustaining antioxidant enzyme activity, providing insights into redox regulation and heat adaptation in mollusks.