不同养殖模式对尼罗罗非鱼（Oreochromis niloticus）生长、免疫性能及水质的影响

为探讨循环水养殖模式(RAS组)和池塘养殖模式(池塘组)对尼罗罗非鱼生长、免疫性能及水质影响的变化规律,开展了为期8周的养殖试验。结果表明：(1)RAS组中鱼体增重率(WGR)(597.36±169.79)显著高于池塘组(470.98±142.99)(P < 0.05),但饲料转化率(FCE)(1.17±0.02)却显著低于池塘养殖系统(1.47±0.03)(P < 0.05)。特定生长率(SGR)和肥满度(CF)也高于池塘养殖系统,但差异不显著(P > 0.05)；(2)在第4周和第8周分别测定了鱼体胃和肠中消化酶活性显示,第4周时,RAS组中肠蛋白酶活性值(1387.56±278.43)显著高于池塘组(1129.99±382.67)(P < 0.05)；第8周时,肠脂肪酶活性(18.11±4.28)显著高于池塘组(12.89±8.00)(P < 0.05)；(3)在第4周和第8周分别测定了鱼体肝胰脏、头肾和血清中碱性磷酸酶(ALP)、溶菌酶 (LSZ)和总超氧化物歧化酶(T-SOD)活性,显示整体上RAS组免疫性能低于池塘组；(4)每周测定水体氨态氮和亚硝态氮含量显示,RAS组氨态氮维持在0.0067 ~ 0.0212 mg / L区间内,亚硝态氮含量位于0.0027 ~ 0.0087 mg / L范围内,均低于池塘组。

Comparison of Growth Performance and Immune Activity of Nile Tilapia (Oreochromis niloticus) and Water Quality in Two Aquaculture Systems

An 8-week experiment was conducted to investigate the growth performance, immunity activity and water quality of Nile tilapia (Oreochromis niloticus) in a recirculating aquaculture system (RAS group) and a pond system (Pond group) respectively. The main results were listed as follows: 1) weight gain rate (WGR) (597.36±169.79) in the RAS group was significantly higher than the Pond group (470.98±142.99) (P < 0.05), whereas feed coefficient rate (FCR) was significantly lower at the meantime (P < 0.05). Besides, specific growth rate (SGR) and condition factor (CF) were also higher with no significant differences (P > 0.05). 2) Stomach and intestine digestive enzyme activity were measured at 4th week and 8th week respectively, which showed that in the 4th week, intestine protease activity in RAS group (1387.56±278.43) was significantly higher than the Pond group (1129.99±382.67) (P < 0.05), and intestine lipase activity in RAS group (18.11±4.28) was significantly higher than the Pond group (12.89±8.00) in the 8th week (P < 0.05). 3) Alkaline phosphatase (ALP), Lysozyme (LZM), and the total superoxide dismutase (T-SOD) in hepatopancreas, head kidney, and serum were determined at the 4th week and 8th week respectively showing that immunity activity in RAS group was subordinated to the Pond group. 4) Ammonia nitrogen and nitrite were measured weekly, and the outcome indicated that ammonia nitrogen maintained at 0.0067 - 0.0212 mg / L, and nitrite sustained at 0.0027 - 0.0087 mg / L respectively. Moreover, both were lower than the Pond group.