The effect of yeast immunity polysaccharide (YSP) on the immunity function in sea cucumber, Apostichopus japonicus selenka

Among a series of dose of Yeast immunity polysaccharide (YSP, 0.2%,0.5% and 1%), the time of the experiment was 21d and the index of immunity was measured at different stages. The result showed that YSP had positive effect on the immunity of Apostichopus japonicus at normal states, which it could hold for some time. Immunity function of most tested groups reached the highest level at the 14th day. The index of the dose (0.5%) was higher than that of control group: the activity of phagocyte, LSZ, ALP and ACP (p<;0.05). On the 21st day, immunity function of most tested groups had decreased. But the index of the dose (0.5% and 1%) was higher than that of the control group (p<;0.05).