Serpins have been characterized from varieties of organisms by their inhibitory roles on serine or cysteine proteases.However,research for the functional study of serpins in crustacean is relatively small.To fully clarify the immune characterizations of serpin,a novel serpin (named Lvserpin8) encoding 414 amino acids with a 19-amino acid signal peptide and a serpin domain was identified from the Pacific white shrimp Litopenaeus vannamei.