Flatfish species such as Scophthalmus maximus, Paralichthys olivaceus, and Cynoglossus semilaevis can achieve long-term survival under low-temperature anhydrous conditions. However, Verasper variegatus shows poor survival performance under single physical cold acclimation, with a maximum survival rate of only 83.33% after 24 h, which limits its long-distance transport. Thus, we investigated the effects of different dormancy-inducing methods on the nutritional and flavor quality of V. variegatus during waterless preservation and transportation, so as to identify a better preservation method. Based on cold acclimation, we applied additional methods including vitamin C immersion, anesthesia, and light exposure. Then we compared the changes in nutritional composition, flavor, and taste characteristics during 0–18 h of waterless preservation and transportation. Results show that the cold acclimation (CA) group consumed more energy to maintain physiological balance under low-temperature and hypoxic stress, leading to a pH drop to 6.63, as well as an 11.80% increase in color value, and a 21.09% increase in springiness. In the light-assisted (LI) group, color remained stable (p>0.05), total water peak area increased by 30.65%, and free amino acids related to umami and sweet taste (Such as glutamic acid and glycine) increased by 26.34%. The vitamin C (VC) group showed significant increase in pH and color difference (p<0.05), while the anesthetic (MS) group exhibited increasing trends in color difference and flavor substances, though texture parameters did not change significantly. Correlation analysis revealed extremely significant correlations texture characteristics (Springiness, gumminess, chewiness) and taste attributes (Umami, sweet, bitter) of free amino acids (p<0.01). In conclusion, light-assisted induced dormancy is a simple, safe, and residue-free method that effectively alleviates stress response and maintains high nutritional and flavor quality in V. variegatus during waterless preservation and transportation.

Saccostrea malabonensis, a dominant species in tropical high-salinity oyster reefs, is often exposed to drastic temperature and frequent temperature fluctuations. To investigate the effects of temperature variations on the carbon budget capacity and potential ecological carbon sink function of S. malabonensis, five temperature gradients (18, 22, 26, 30, and 34 ℃) were established. Key physiological parameters were measured at each temperature, and the corresponding energy and carbon budget models were constructed. Among them, the filtration rate, ingestion rate, and oxygen consumption rate showed no significant difference between 30 and 34 ℃ groups (p>0.05), but were significantly higher than those in lower temperature treatment groups, specifically 18, 22, and 26 ℃ groups (p<0.05); the fecal pellet production rate at 34 ℃ was significantly higher than that in other temperature treatment groups (p<0.05); except for 26 and 34 ℃ groups, there was no significant difference in ammonia excretion rate among temperature treatment groups (p>0.05). Assimilation efficiency increased first and then decreased with temperature, reaching a peak at 30 ℃ (59.01%), and was significantly higher than that in 18 and 22 ℃ groups (p<0.05); the oxygen-nitrogen ratio (O/N) in the 26, 30, and 34 ℃ treatment groups (20.49–24.62) was significantly higher than that in 18 and 22 ℃ groups (9.18–13.85) (p<0.05). In terms of energy allocation, except for 30 ℃ groups, all treatment groups showed that fecal energy accounted for the largest proportion (40.53%–72.19%), followed by growth energy (21.61%–55.94%), with excretion energy accounting for the smallest proportion (0.21%–0.90%). Carbon budget results showed that fecal carbon increased with rising temperature, while growth carbon was highest at 30 ℃ (1.94 mg·g⁻¹·h⁻¹). The proportions of carbon budget components varied in a pattern similar to energy allocation: the proportion of fecal carbon first decreased and then increased, while the proportion of growth carbon showed the opposite trend. This study shows that 30 ℃ is the optimal temperature for S. malabonensis, at which the species can achieve the most stable metabolism, effective individual growth, and maximal carbon fixation potential.