生物絮团系统中不同低盐度条件对水质及凡纳滨对虾生理指标的影响

为探讨生物絮团养殖系统在低盐度条件下对凡纳滨对虾生理健康的影响，本研究以凡纳滨对虾为养殖对象，在生物絮团养殖系统中设置5‰（S5组）、10‰（S10组）和15‰（S15组）3个不同的低盐度组，进行为期4周的养殖实验。结果表明，各处理组间的水质指标没有明显区别(P>0.05)，均在适合对虾养殖的范围内。凡纳滨对虾的生长、肌肉水分、粗蛋白和粗脂肪含量在各组间没有明显区别(P>0.05)，但S10组的灰分含量显著高于S5组和S15组(P<0.05)。在S5组的盐度条件下，凡纳滨对虾肠道的淀粉酶和胰蛋白酶活性显著提高(P<0.05)，S15组的盐度条件下对虾的血清抗氧化水平显著提高(P<0.05)。由此可见，凡纳滨对虾在低盐度生物絮团养殖系统中的生长不受显著影响，但抗氧化水平和消化酶活会受到显著影响。本研究可为对虾生物絮团养殖系统的盐度调控提供参考。

Effects of Different Low Salinity Conditions on Water Quality and Physiological Indexes of Litopenaeus vannamei in Biofloc Technology System

In order to study the effect of biofloc technology system on the physiological health of Litopenaeus vannamei under low salinity condition, this paper took Litopenaeus vannamei as the culture object, and set up 3 different low salinity groups of 5‰ (S5 group), 10‰ (S10 group) and 15‰ (S15 group) in the biofloc technology system for 4 weeks. The results showed that there was no significant difference in water quality indicators among the three groups (P>0.05), which were within the range suitable for shrimp culture. The growth, and muscle moisture, muscle crude protein and muscle crude fat contents of Litopenaeus vannamei were not significantly different among the groups (P>0.05), but the muscle ash content of S10 group was significantly higher than that of S5 group and S15 group (P<0.05). Under the salinity condition of S5 group, the amylase and trypsin activities of Litopenaeus vannamei intestinal tract were significantly increased (P<0.05), and the serum antioxidant activities of Litopenaeus vannamei were significantly increased under the salinity condition of S15 group (P<0.05). It can be seen that the growth of Litopenaeus vannamei in the low salinity biofloc technology system will not be significantly affected, but the antioxidant level and digestive enzyme activities will be significantly affected. This study can provide reference for salinity regulation of shrimp culture in biofloc technology system.