杂交黄颡鱼与普通黄颡鱼幼鱼生长性能及耐低氧能力的比较

实验以杂交黄颡鱼(Pelteobagrus fulvidraco)和普通黄颡鱼幼鱼为实验对象, 拟通过8周的投喂生长和低氧胁迫实验, 比较研究杂交黄颡鱼与普通黄颡鱼的生长性能及耐低氧抗逆性。投喂生长实验: 经过8周的养殖, 杂交黄颡鱼平均体重为(19.60±0.88) g/尾, 显著高于普通黄颡鱼平均体重为(15.74±0.42) g/尾(P<0.05), 杂交黄颡鱼幼鱼较普通黄颡鱼幼鱼体重生长快24.52%; 杂交黄颡鱼幼鱼存活率为(87.78±1.92)%, 显著高于普通黄颡鱼幼鱼存活率(67.78±1.92)% (P<0.05), 杂交黄颡鱼幼鱼比普通黄颡鱼幼鱼存活率高 29.51%; 杂交黄颡鱼的饲料系数为1.18±0.14, 普通黄颡鱼饲料系数为1.36±0.21。低氧胁迫实验: 同时将杂交黄颡鱼和普通黄颡鱼置于在溶氧量(1.48 ± 0.27) mg/L的水体中, 分别在低氧胁迫0、6h、12h和24h后, 检测血清和肝脏中抗氧化酶活性以及脑和肝脏中缺氧诱导基因(HIF-1α)的相对表达量发现: 杂交黄颡鱼和普通黄颡鱼血清和肝脏中乳酸脱氢酶(LDH)活性、超氧化物歧化酶(SOD)活性和过氧化氢酶(CAT)活性在低氧胁迫后 6h以及总抗氧化能力(T-AOC)在低氧胁迫后 12h较低氧胁迫 0均出现显著性变化(P<0.05)且在低氧胁迫6h、12h和24h杂交黄颡鱼抗氧化酶活性均高于普通黄颡鱼; 杂交黄颡鱼和普通黄颡鱼脑和肝脏中缺氧诱导基因(HIF-1α)的相对表达量均在低氧胁迫后出现显著性上升(P<0.05)且在低氧胁迫6h、12h和 24h杂交黄颡鱼缺氧诱导基因(HIF-1α)的相对表达量均高于普通黄颡鱼。从无氧代谢能力、抗氧化能力以及缺氧诱导基因相对表达量3方面分析表明杂交黄颡鱼和黄颡鱼低氧胁迫短时间均具有一定的低氧耐受能力但随着胁迫时间延长均会出现氧化损伤且杂交黄颡鱼的耐低氧能力要显著性高于普通黄颡鱼。

THE GROWTH CHARACTERISTICS AND HYPOXIA TOLERANT ABILITY OF YELLOW CATFISH AND HYBRID CATFISH

This study investigated growth performance and hypoxia tolerant ability of the yellow catfish and the hybrid catfish called “Huangyou No. 1” for an 8-week trial. The results showed that the average weight of the hybrid catfish was (19.60±0.88) g/tail at week 8, which was significantly higher than that of the yellow catfish was (15.74±0.42) g/tail (P<0.05) with a 24.52% increase. The feed coefficient of the hybrid catfish and the yellow catfish were 1.18±0.14 and 1.36±0.21, respectively. The survival rate of young hybrids catfish was 87.78±1.92, which was significantly higher than that of the yellow catfish at 67.78±1.92 (P<0.05). The survival rate of the hybrid catfish was 29.51% higher than that of the yellow catfish. The hybrid catfish and yellow catfish were placed in water with dissolved oxygen content of (1.48±0.27) mg/L and then hypoxia stress for 0, 6h, 12h and 24h before collecting serum and liver for measurements. Hypoxia stress significantly regulated the LDH activity, SOD activity, CAT activity at 6h and the T-AOC at 12h in the serum and liver of both hybrid catfish and yellow catfish (P<0.05). The brain and liver HIF-1α mRNA level of both hybrid catfish and yellow catfish increased significantly by hypoxic stress (P<0.05) with higher level in hybrid catfish at 6h, 12h and 24h. These results indicated that long-term hypoxic stress may cause oxidative damage to hybrid catfish and yellow catfish, but hypoxia tolerance of hybrid catfish is higher than that of yellow catfish.