Effects of dietary calcium levels on regulation of serum osmolality and ion levels in Japanese seabass Lateolabrax japonicus in freshwater
SONG Jun-ying,WANG Ling,ZHANG Chun-xiao,SONG Kai,HU Shui-cheng,ZHANG Lu
1. Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Key Laboratory for Feed Quality Testing and Safety Evaluation, Jimei University, Xiamen 361021, China; 2. Tongwei Co. Ltd. , Chengdu 610041, China
Abstract: A feeding trial was conducted to investigate effects of dietary calcium（Ca） levels on serum osmolality,serum ion levels and activities of relative enzymes regulating osmolality in Japanese seabass Lateolabrax japonicus cultured in freshwater.Japanese seabass juveniles with body weight of（12.47 ± 0.01） g were fed six iso-nitrogenous and iso-energetic diets containing calcium（Ca） of 0.29%（D1）,0.42%（D2）,0.65%（D3）,0.79%（D4）,1.02%（D5） and 3.10%（D6） for 8 weeks.The results showed that there was significantly higher serum osmolality in groups D1 and D2 than that in groups D3,D4 and D5（P 〈 0.05）,without significant difference among groups D1 and D2 and group D6（P 〉 0.05）.Serum Na＋and Cl-levels were shown to be increased and then decreased as dietary Ca levels increased（P 〈 0.05）,lower in D1,D2 and D6 groups than those in other treatments.The maximal serum Ca2 ＋level was observed in group D5 and the minimal value in group D6,without significant difference among other groups（P 〉 0.05）.With the elevation of dietary Ca level,the Na＋/ K＋-ATPase（NKAase） activity in gill was decreased and then increased,the maximum in group D1（P 〈 0.05）,while the Ca2 ＋-ATPase（CAase） activity was significantly decreased and the maximum also in group D1（P 〈 0.05）; the intestinal NKAase activity was increased first and then decreased and reached the highest value in group D3（P 〈 0.05）,and the higher intestinal CAase activity appeared in groups D1 and D3 and the minimum in group D6.The activities of NKAase and CAase in kidney were all decreased first and then increased as dietary Ca levels increased,the maximal kidney NKAase activity in group D1 and the minimum in group D4,however the higher CAase activity was in groups D1 and D3 and the minimum in group D4.Japanese seabass fed the low Ca diets（0.29%,and 0.42%） and the high Ca diet（3.10%） both showed high osmotic regulation,and the diets containing 0.65%-1.02% Ca will be benefit for the osmotic
宋俊英, 王玲, 张春晓, 宋凯, 胡水城, 张璐. 饲料钙水平对淡水养殖鲈血清渗透压和离子调节的影响[J]. 大连海洋大学学报, 2015, 30(6): 653-659.
SONG Jun-ying, WANG Ling, ZHANG Chun-xiao, SONG Kai, HU Shui-cheng, ZHANG Lu. Effects of dietary calcium levels on regulation of serum osmolality and ion levels in Japanese seabass Lateolabrax japonicus in freshwater. Journal of Dalian Ocean University, 2015, 30(6): 653-659.
2015, Vol. 30 
