Abstract：
Se is an essential trace element associated with animal growth and antioxidant and metabolic processes. However, whether Se, especially organic Se with higher bioavailability, can alleviate the adverse effects of low salinity stress on marine economic crustacean species has not been investigated. Accordingly, juvenile Pacific white shrimp (Litopenaeus vannamei) were reared in two culture conditions (low and standard salinity) fed diets supplemented with increasing levels of l-selenomethionine (0·41, 0·84 and 1·14 mg/kg Se) for 56 d, resulting in four treatments: 0·41 mg/kg under standard seawater (salinity 31) and 0·41, 0·84 and 1·14 mg/kg Se under low salinity (salinity 3). The diet containing 0·84 mg/kg Se significantly improved the survival and weight gain of shrimp under low salinity stress and enhanced the antioxidant capacity of the hepatopancreas. The increased numbers of B and R cells may be a passive change in hepatopancreas histology in the 1·14 mg/kg Se group. Transcriptomic analysis found that l-selenomethionine was involved in the regulatory pathways of energy metabolism, retinol metabolism and steroid hormones. In conclusion, dietary supplementation with 0·84 mg/kg Se (twice the recommended level) effectively alleviated the effects of low salinity stress on L. vannamei by regulating antioxidant capacity, hormone regulation and energy metabolism.
摘要：
硒（Se）是与动物生长，抗氧化和代谢过程相关的必需微量元素。然而,是否Se，特别是有机硒具有较高的生物利用度，能否缓解低盐度胁迫对海洋经济甲壳类动物的不利影响尚未被研究。因此，幼年太平洋白虾（凡纳滨对虾）在两种培养条件（低盐度和标准盐度）饲喂饮食中饲养56天，补充了L-硒代蛋氨酸（0.41、0.84和1.14mg/kgSe）。导致四种处理：标准海水（盐度31）下的0.41mg/kg和低盐度（盐度3）下的0.41、0.84和1.14mg/kgSe。饲粮含0.84mg/kg硒显著提高了低盐度胁迫下对虾的存活率和增重,增强了肝胰腺的抗氧化能力。在1.14mg/kgSe组中，B和R细胞数量的增加可能是肝耳蜗组织学的被动变化。转录组学分析发现,L-硒代蛋氨酸参与能量代谢的调控途径,视黄醇代谢和类固醇激素。总之,饲粮补充0.84mg/kg硒(推荐水平的两倍),通过调节抗氧化能力,有效缓解了低盐度胁迫对南美白对虾的影响,激素调节和能量代谢。
