Dawood Mahmoud A O, Sewilam Hani
Animal Production Department, Faculty of Agriculture, Kafrelsheikh University, Kafr El-Sheikh, Egypt.
The Center for Applied Research on the Environment and Sustainability, The American University in Cairo, Cairo, Egypt.
J Exp Zool A Ecol Integr Physiol. 2023 Jan;339(1):74-82. doi: 10.1002/jez.2654. Epub 2022 Sep 11.
One of the most critical factors affecting aquaculture efficiency is the capability of releasing ammonia from the water. By applying a high salinity strategy, this study provides a prompt approach for removing high ammonia levels and relieving its adverse impacts on common carp. The study investigated five groups with triplicates where the control was kept with fresh water, and the remaining four groups stressed with different salinity levels (5, 10, 15, and 20 ppt) for 8 weeks. Then fish were exposed to unionized ammonia (NH ) stress (0.5 ppm) for 6 h. The final weight (FBW) and weight gain (WG) showed lower values in fish stressed with 15 and 20 ppt salinity levels than fish reared in 0 and 5 ppt salinity levels (p < 0.05). The lowest FBW and WG and the highest feed conversion ratio were shown in fish grown in 20 ppt (p < 0.05). The survival rate was markedly lowered by 15 and 20 ppt salinity levels (p < 0.05), while no significant differences were observed among 0, 5, and 10 ppt salinity levels (p > 0.05). Liver condition-related indices (alanine aminotransferase, aspartate aminotransferase, and alanine aminotransferase) were markedly increased in fish grown in 15 and 20 ppt before or after ammonia stress (p < 0.05). The results showed higher creatinine levels in fish raised in 15 and 20 ppt than the remaining salinity levels, with the highest value in fish of 20 ppt salinity before and after ammonia stress (p < 0.05). Markedly the blood glucose and cortisol levels were upraised in fish reared in 10, 15, and 20 ppt before and after ammonia stress (p < 0.05). The glucose level was not significantly different in fish reared in 5 ppt than 0 and 10 ppt salinity levels (p < 0.05). Generally, the blood glucose and cortisol levels were decreased markedly after ammonia stress than before ammonia stress (p < 0.05). Interestingly, total protein, albumin, and globulin levels were increased in common carp reared in different salinity levels after ammonia stress (p < 0.05). In conclusion, ammonia toxicity combined with high salinity resulted in a regulatory effect on the hepato-renal function and stress-related markers in common carp.
影响水产养殖效率的最关键因素之一是水体释放氨的能力。通过采用高盐度策略，本研究提供了一种快速去除高氨水平并减轻其对鲤鱼不利影响的方法。该研究调查了五组，每组重复三次，对照组保持在淡水中，其余四组在不同盐度水平（5、10、15和20 ppt）下胁迫8周。然后将鱼暴露于非离子氨（NH）胁迫（0.5 ppm）下6小时。与在0和5 ppt盐度水平下养殖的鱼相比，在15和20 ppt盐度水平下胁迫的鱼的终末体重（FBW）和体重增加（WG）值较低（p < 0.05）。在20 ppt盐度下养殖的鱼显示出最低的FBW和WG以及最高的饲料转化率（p < 0.05）。15和20 ppt盐度水平显著降低了存活率（p < 0.05），而在0、5和10 ppt盐度水平之间未观察到显著差异（p > 0.05）。在氨胁迫前后，在15和20 ppt盐度下养殖的鱼的肝脏状况相关指标（丙氨酸转氨酶、天冬氨酸转氨酶和丙氨酸转氨酶）显著升高（p < 0.05）。结果显示，在15和20 ppt盐度下养殖的鱼的肌酐水平高于其余盐度水平，在氨胁迫前后，20 ppt盐度的鱼的肌酐水平最高（p < 0.05）。在氨胁迫前后，在10、15和20 ppt盐度下养殖的鱼的血糖和皮质醇水平显著升高（p < 0.05）。在5 ppt盐度下养殖的鱼的血糖水平与0和10 ppt盐度水平相比无显著差异（p < 0.05）。一般来说，氨胁迫后血糖和皮质醇水平比氨胁迫前显著降低（p < 0.05）。有趣的是，氨胁迫后，不同盐度水平下养殖的鲤鱼的总蛋白、白蛋白和球蛋白水平升高（p < 0.05）。总之，氨毒性与高盐度相结合对鲤鱼的肝肾功 能和应激相关指标产生了调节作用。
