为了探索大鳞鲃经盐度驯化后的血液生理生化、免疫应激的适应性变化，选择体长为(15.09±3.54) cm，体重为(13.66±1.26) g的幼鱼，设置了3个组别，空白组始终处于淡水中养殖，驯化组经4 g/L的盐度适应性驯养168 h后再放入8 g/L的盐度水体中，未驯化组直接放入8 g/L的盐度水体中，分别测定并比较放入8 g/L盐度水体中第0、6、12、24、48、96和168 小时幼鱼血液生理生化和免疫应激相关指标变化。结果显示，① 驯化组和未驯化组幼鱼血液中的血常规指标[白细胞(WBC)、淋巴细胞(Lymph)、单核细 胞(Mon)、中性粒细胞(Gran)、红细胞(RBC)、血红蛋白(HGB)含量]、血浆生理生化指标[尿素(UREA)浓度、血清葡萄糖(GLU-G)和白蛋白(ALB)含量、血浆渗透压)、鳃组织中的天门冬氨酸氨基转移酶(ACP)、碱性磷酸酶(AKP)、乳酸脱氢酶(LDH)和肝脏组织中抗氧化指标[超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽酶(GSH-Px)、丙二醛(MDA)含量]在盐度为8 g/L的水体中，均随着胁迫时间的延长呈现出先升高后降低的现象。② 胁迫初期，驯化组和未驯化组幼鱼的各生化指标在相同组织内到达峰值的时间相同，但驯化组幼鱼血浆中的生理生化指标(WBC、Lymph、Gran、Mon、UREA、GLU-G、ALB、渗透压)和转氨酶(AST、ALT)、肝组织中的抗氧化酶(SOD、CAT、GSH-Px、MDA)上升幅度和峰值大小均显著性小于未驯化组。③ 在8 g/L NaCl盐度胁迫168 h后，驯化组和未驯化组均能够恢复到对照组水平，但驯化组的大鳞幼鱼血浆渗透压、血浆ALB含量均早于未驯化组恢复到对照组水平。研究表明，经4 g/L的盐度驯化后的大鳞鲃幼鱼遭受8 g/L NaCl盐度环境胁迫时，显示出较好的生理生化自我调节和恢复能力。

In saltwater fish culture, directly releasing freshwater-cultured fry into medium to high salinity water typically results in high mortality due to environmental adaptation challenges. However, prior adaptive acclimation in low to medium salinity environments can enhance fry resistance and improve survival rates. This study investigated the physiological, biochemical, and immune stress responses of Luciobarbus capito following salinity acclimation. Juvenile fish, averaging (15.09±3.54) cm in length and (13.66±1.26) g in weight, were divided into three groups: a control group maintained in freshwater, an acclimated group preconditioned at 4 g/L salinity for 168 hours before exposure to 8 g/L saltwater, and a non-acclimated group directly introduced in 8 g/L saltwater. Physiological, biochemical, and immune stress indicators were measured at 0, 6, 12, 24, 48, 96 and 168 h in all groups. The results indicated that, (i) the blood routine indexes (WBC, Lymph, Mon, Gran, RBC, HGB contents), plasma physiological and biochemical indexes (UREA concentration, GLU-G and ALB contents, plasma osmotic pressure), ACP, AKP, LDH in gill tissue and antioxidant indexes (SOD, CAT, GSH-Px, MDA content) in liver tissue of acclimated group and non-acclimated group all showed an increasing first and then decreasing with the extension of stress time. (ii) In the early stage of salinity stress, the biochemical indexes of juveniles in both acclimated and non-acclimated groups reached their peak at the same time. However, the amplitude and peak size of the physiological and biochemical indexes (WBC, Lymph, Gran, Mon, Urea, GLU-G, ALB, osmotic pressure), transaminases (AST, ALT) and antioxidant enzymes (SOD, CAT, GSH-Px, MDA) of liver tissue were significantly lower than those of non-acclimated group (P<0.05). (iii) After 7 days of 8 g/L NaCl salinity stress, both the acclimated and non-acclimated could recover to the level of the control group, but the plasma osmotic pressure and plasma ALB content of the L. capito juvenile in the acclimated group recovered to the level of control group earlier than those in the non-acclimated group. The study's findings suggest that L. capito juveniles acclimated at 4 g/L salinity exhibit superior physiological and biochemical self-regulation and recovery ability when subjected to 8 g/L salinity stress.

S 917.4

国家重点研发计划(2020YFD0900402，2019YFD0900405)；中国水产科学研究院基本科研业务费专项(2020TD56)