Cobalt (Co) is an important component of vitamin B₁₂, but is toxic to aquatic animals at a high level. In this study, the Pacific white shrimp, Litopenaeus vannamei were exposed to three Co concentrations (0, 100, and 1000 μg/L) for 4 weeks. The survival and condition factor in shrimp exposed to the Co treatments were not different from the control, but the shrimp exposed to 100 μg Co/L gained more weight than in other two groups, and the shrimp exposed to 1000 μg Co/L gained less weight than in other groups. The SOD and GSH-PX activities were higher in shrimp exposed to 100 μg Co/L, but lower in the shrimp exposed to 100 μg Co/L compared with the control, respectively. The MDA contents in the hepatopancreas decreased in the 100 μg Co/L, but increased in the 1000 μg Co/L. The serum lysozyme decreased with ambient cobalt, was lower in the shrimp exposed to 1000 μg Co/L than in other two groups. The expression of C-type lectin 3 was down-regulated by Co concentrations. The Toll and immune deficiency in shrimp exposed to 100 μg Co/L was higher than in other two groups. The mucin-1 was lower in the 1000 μg Co/L group than in other two groups, but mucin-2 and mucin-5AC were higher in the 1000 μg Co/L group than in the control. With increasing Co concentration, Shannon and Simpson indexes of the intestinal microbial communities were decreased. The abundance of pathogenic bacteria (Ruegeria and Vibrio) increased in both Co groups. This study indicates that chronic exposure to waterborne cobalt could affect growth, cause oxidative stress, stimulate the immune response, damage intestinal histology, and reshape intestinal microbiota community L. vannamei.

钴（Co）是维生素B ₁₂的重要成分，但对水生动物的毒性很高。在这项研究中，太平洋白对虾凡纳滨对虾暴露于三种Co浓度（0、100和1000μg/ L）达4周。暴露于Co处理的虾的存活率和条件因子与对照无差异，但是暴露于100μgCo / L的虾比其他两组体重增加，而暴露于1000μgCo / L的虾的体重减少。体重要比其他人群高。与对照相比，暴露于100μgCo / L的虾中SOD和GSH-PX活性较高，但是暴露于100μgCo / L的虾中SOD和GSH-PX活性较低。肝胰腺中的MDA含量在100μgCo / L中降低，但在1000μgCo / L中升高。血清溶菌酶随环境钴而降低，暴露于1000μgCo / L的虾中的溶菌酶低于其他两组。Co浓度下调C型凝集素3的表达。暴露于100μgCo / L的虾的Toll和免疫缺乏症高于其他两组。1000μgCo / L组的mucin-1低于其他两组，但是1000μgCo / L组的mucin-2和mucin-5AC高于对照组。随着钴浓度的增加，肠道微生物群落的香农和辛普森指数下降。致病菌丰富（两个Co组的Ruegeria和弧菌（Vibrio）均增加。这项研究表明，长期暴露于水合钴可能会影响生长，引起氧化应激，刺激免疫反应，破坏肠道组织学并重塑肠道微生物群南美白对虾。