Haemocyanin content of shrimp (Fenneropenaeus chinensis) associated with white spot syndrome virus and Vibrio harveyi infection process.

Haemocyanin (Hc) is frequently reported to vary significantly by physiological status and environmental stress in Crustaceans. In this paper, the shrimp Fenneropenaeus chinensis was infected with different concentrations of white spot syndrome virus (WSSV) and Vibrio harveyi. Then, the variation of Hc and total protein content of the haemolymph (TPCH) were investigated using the established double antibody sandwich enzyme linked immunosorbent assay (DAS-ELISA) and Coomassie brilliant blue method, respectively. The results showed that the Hc content peaked at 12xa0h post-infection (PI) in the 10(-2), 10(-4) and 10(-6) viral supernatant (VS) groups, and the maximum was 93.03xa0±xa02.55xa0mgxa0ml(-1), 77.57xa0±xa06.02xa0mgxa0ml(-1) and 70.25xa0±xa03.96xa0mgxa0ml(-1), respectively. TPCH reached the maximum of 108.18xa0±xa01.36xa0mgxa0ml(-1) and 103.49xa0±xa01.33xa0mgxa0ml(-1) at 12xa0h PI in the 10(-2) and 10(-4) VS groups, respectively. The maximum was 96.94xa0±xa01.06xa0mgxa0ml(-1) at 24xa0h PI in the 10(-6) VS group. In the V.xa0harveyi infection groups, the Hc content reached a maximum of 87.97xa0±xa04.39xa0mgxa0ml(-1) at 36xa0h PI in the 10(6)xa0CFUxa0ml(-1) group, 73.74xa0±xa04.38xa0mgxa0ml(-1) and 72.47xa0±xa02.09xa0mgxa0ml(-1) at 12xa0h PI in the 10(7) and 10(8)xa0CFUxa0ml(-1) groups, respectively. TPCH reached a maximum of 111.16xa0±xa00.86xa0mgxa0ml(-1) at 36xa0h PI in the 10(6)xa0CFUxa0ml(-1) group, 100.41xa0±xa00.51xa0mgxa0ml(-1) and 101.94xa0±xa00.47xa0mgxa0ml(-1) at 12xa0h PI in the 10(7) and 10(8)xa0CFUxa0ml(-1) groups, respectively. These data showed that both Hc content and TPCH varied as the same extent after infection. The up-regulation of the Hc content at 6-36xa0h PI might be a reference threshold for shrimp infection.