Changes in temperature and salinity of the marine environment fluctuate continuously, and the effects of these changes on shellfish survival are significant. In this study, the survival rate of adult Asian green mussels (Perna viridis) was measured after short-term treatments (7 days) for a range of temperature (20 °C, 25 °C, 30 °C) and salinity (23‰, 28‰, 33‰). The digestive (amylase, lipase, trypsin and pepsin activities) and antioxidant performance (SOD and GPX gene expression; SOD, GPX and CAT activities; GSH and MDA Concentration) were measured and MANOVA results were obtained using a generalized linear model between certain factors (temperature (T), salinity (S) and temperature × salinity (T × S)) and survival rate. Both T and T × S significantly affected the survival rate of Asian green mussels. The overall relationship between the survival rate of P. viridis and T and S within the experimental range can be summarised by the equation: ln(Survival rate) = 54.9282 − 2.5627 × T − 3.6180 × S + 0.1857 × T × S + 0.0156 × T2 + 0.0520 × S2 − 0.0012 × T2 × S − 0.0023 × T × S2. The optimal temperature–salinity combination was 23.698 °C/30.760‰. T, S and T × S all had a significant impact on amylase and lipase activities of Asian green mussels. In the hepatopancreas, gill, mantle, adductor muscle, gonad and foot tissues of Asian green mussel, the SOD and GPX gene expression were responsive to temperature–salinity changes. The antioxidant performance of the combinations far from the optimal temperature–salinity combination were significantly improved. Our results suggest that combined temperature and salinity effects have a regular impact on the survival of Asian green mussels and that there is a link between survival and digestive and antioxidant performance.

A water environment can impact many physiological processes of aquatic animals. The antioxidant response of immune system of the pearl oyster to temperature and salinity is of great significance to health. This study analyzed the physiological changes and immune responses under different temperature and salinity levels (temperature: 20, 25, and 30 °C; salinity: 23, 28, and 33‰) in the short term (7 d) in the hepatopancreas and other tissues of 405 pearl oysters. The combined effects of temperature and salinity on antioxidants in the immune system of the pearl oyster were evaluated via response surface methodology and Box–Benhnken design (BBD) under laboratory conditions. The secondary effects of salinity on the activities of glutathione peroxidase (GSH-PX), catalase (CAT), and superoxide dismutase (SOD) were significant, and CAT and SOD showed an inverted U-shaped trend with the increase in salinity. Temperature significantly impacted GSH-PX, CAT, glutathione (GSH), and SOD in primary and secondary effects, and the maximum values of CAT, GSH, and SOD were observed. The phenoloxidase (POX) and alkaline phosphatase (AKP) activities increased with the increasing temperatures. The interaction of temperature and salinity was significant on CAT and SOD, but was not significant on GSH-PX. The interaction between salinity and temperature on AKP was significant, which was contrary to the results of AKP in the hemolymph. The expression levels of antioxidant genes varied between tissues, and the expression levels of different genes in the same tissue were different. Appropriate immunity and antioxidant index models were established under the combined temperature and salinity conditions. The optimal combination of temperature and salinity was 24.95 °C and 28.11‰, respectively, and the desirability was 0.803. This study provides theoretical reference points for the pearl oyster to respond to temperature and salinity changes and can be used to establish an index model for shellfish aquaculture.

Bosten Lake and Taitema Lake are important inland lakes in arid Northwest China, but recent fish-assemblage variation in these systems remains poorly resolved. We surveyed fish communities at 10 sites in Bosten Lake and four sites in Taitema Lake from 2023 to 2025 using standardized conventional capture methods. Across the three years, 20 species from 7 orders and 12 families were recorded in Bosten Lake and 12 species from 6 orders and 9 families in Taitema Lake; Cyprinidae was the most species-rich family in both lakes. The cumulative observed species pool and effort-standardized richness were higher in Bosten Lake, but year-specific site-level richness contrasts were not significant after Holm adjustment. Community composition differed between lakes after adjustment for year using exact whole-site permutations (Bray–Curtis PERMANOVA: pseudo-F1,38 = 37.92, partial R² = 0.499, p = 0.0010), although multivariate dispersion also differed (PERMDISP: F = 5.46, p = 0.030). Site-restricted PERMANOVA detected year effects in Bosten Lake (pseudo-F2,18 = 29.37, partial R² = 0.765, p < 0.001) and Taitema Lake (pseudo-F2,6 = 156.36, partial R² = 0.981, exact p = 0.0046). Bosten Lake had higher Margalef richness (Taitema minus Bosten: −0.818, 95% CI −1.451 to −0.185, p = 0.016) and Pielou evenness (−0.056, 95% CI −0.105 to −0.008, p = 0.027), whereas Shannon–Wiener diversity did not differ detectably between lakes (−0.169, 95% CI −0.673 to 0.335, p = 0.478). After controlling for site and year, no diversity–environment correlation remained significant after false-discovery-rate correction, and the partial RDA test of within-site temporal environmental–community covariation was nonsignificant (pseudo-F2,24 = 1.285, partial R² = 0.097, p = 0.1754). Thus, the study documents clear spatial separation between lakes and interannual variation within lakes, but does not identify the retained environmental variables as statistically robust drivers of those patterns.