中文摘要：

以初始体重为（6.77±0.01） g的仿刺参（Apostichopus japonicus Selenka）为实验对象，在基础饲料中添加1%不同分子量的壳聚糖，分子量分别为35 kDa和400 kDa，进行为期56 d的养殖实验，研究低分子壳聚糖（LMWC）和高分子壳聚糖（HMWC）对仿刺参生长和免疫相关酶活性的影响。结果显示，不同分子量的壳聚糖对仿刺参的生长均有促进作用，且LMWC能显著促进刺参的特定生长率（SGR）（P〈0.05）。饲料中添加不同分子量壳聚糖，刺参体腔细胞中的总超氧化物歧化酶（T-SOD）活性比对照组均显著增高（P〈0.05）。LMWC可显著增强刺参体腔细胞中酸性磷酸酶（ACP）活性（P〈0.05），并能提高碱性磷酸酶（AKP）和一氧化氮合酶（NOS）活性。HMWC对刺参体腔细胞中AKP和NOS活性均有显著增强作用（P〈0.05）。研究表明，在刺参饲料中添加一定量的壳聚糖，对其生长和相关免疫酶活性有促进作用。

英文摘要：

In this study we designed an 8-week experiment to determine the effect of dietary chitosan with low molecular weight （LMWC, 35 kDa） or high molecular weight （HMWC, 400 kDa） on the growth and immunity of the sea cucumbers （Apostichopus japonicus Selenka）. The initial average weight of the sea cucumbers was （6.77±0.01） g. The basic diet was used as control and the experimental diets were supplemented with 1% of chitosan. The results showed that both LMWC and HMWC promoted the growth of sea cucumbers, and that the specific growth rate （SGR） of the LMWC group was significantly higher than the control group （P〈0.05）. Compared to the control, the activity of the total superoxide dismutase （T-SOD） in coelomocytes was significantly increased in experimental groups （P〈0.05）. LMWC enhanced the activities of acid phosphatase （ACP） （P〈0.05）, alkaline phosphatase （AKP）, and nitric oxide synthase （NOS）. The activities of AKP and NOS in the HMWC group were also significantly higher than those in the control group （P〈0.05）. These data suggested that dietary chitosan might enhance the growth and the activities of immunity-related enzymes in sea cucumbers.