Maoxiao Peng, Bo Ye, Xiaojun Liu, Donghong Niu, Tianyi Lan, Zhiguo Dong, Jiale Li
Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China.
Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Huaihai Institute of Technology, Lianyungang, China.
Front Physiol. 2018 May 18;9:552. doi: 10.3389/fphys.2018.00552. eCollection 2018.
In order to clarify the possibility of rearing razor clams () in inland saline water (ISW) and to facilitate their breeding under these stressful conditions, we performed semi-static acute and chronic toxicity tests to determine the effects of carbonate alkalinity (CA) and pH on the survival and growth rate, and critical metabolic enzyme activity in juvenile of (JSC). (1) Acute toxicity test. As the water increased from 1.22 to 45.00 mmol L, the survival rate decreased significantly, which was exacerbated by the increase in the pH. When the water was set at 2.5 mmol L, the 48 h lethal concentration 50% (LC) for JSCs with respect to pH was 9.86. When the water pH was 9.0, 9.5, and 10.0, the 48 h LC values for JSCs with respect to were 10.38, 8.79, and 3.11 mmol L, respectively. (2) Chronic toxicity test. Four experimental groups comprising the control, CAS, pHS, and CA-pHS were designated according to the target ISW data. After 3 months of stress, the JSC survival rate in each group exceeded 85%, but survival was significantly lower in the CA-pHS group than the control group ( < 0.05) in the first month. For the JSCs in various groups, the shell length growth rate (SGR) and weight gain (WG) rate were significantly lower in the CA-pHS group than the other groups ( < 0.05 for SGR; < 0.001 for WG) in the first month. However, the difference in the growth rate among groups decreased in the next 2 months. For the JSCs in the CA-pHS group, the oxygen consumption, ammonia-N excretion, Na/K-ATPase, aspartate aminotransferase, and superoxide dismutase levels were significantly higher than those in the other groups during the first month, but there were no significant differences between the groups subsequently. The acetylcholinesterase and lysozyme levels did not differ significantly among groups during stress for 3 months. The integrated biomarker response index showed that stressors comprising high pH and could be tolerated well by JSCs over long periods of stress. These results indicate that water and pH together affect the survival, growth, and physiological activity of JSCs. is suitable for culture in ISW.
为了阐明在内陆咸水（ISW）中养殖缢蛏的可能性，并促进其在这些应激条件下的繁殖，我们进行了半静态急性和慢性毒性试验，以确定碳酸碱度（CA）和pH对缢蛏稚贝（JSC）的存活、生长率以及关键代谢酶活性的影响。（1）急性毒性试验。随着水体CA从1.22 mmol/L增加到45.00 mmol/L，存活率显著下降，且pH升高会加剧这种情况。当水体CA设定为2.5 mmol/L时，JSC在48小时的半数致死浓度（LC50）对应的pH为9.86。当水体pH为9.0、9.5和10.0时，JSC在48小时的LC值对应的CA分别为10.38、8.79和3.11 mmol/L。（2）慢性毒性试验。根据目标ISW数据设定了包括对照组、CAS组、pHS组和CA - pHS组在内的四个实验组。应激3个月后，各组JSC的存活率均超过85%，但在第一个月，CA - pHS组的存活率显著低于对照组（P < 0.05）。对于各组JSC，在第一个月，CA - pHS组的壳长生长率（SGR）和体重增加率（WG）显著低于其他组（SGR的P < 0.05；WG的P < 0.001）。然而，在接下来的2个月中，各组间生长率的差异减小。对于CA - pHS组的JSC，在第一个月，其耗氧量、氨氮排泄量、钠钾ATP酶、天冬氨酸转氨酶和超氧化物歧化酶水平显著高于其他组，但随后各组间无显著差异。在3个月的应激期间，各组间乙酰胆碱酯酶和溶菌酶水平无显著差异。综合生物标志物响应指数表明，在长时间应激下，高pH和CA等应激源能被JSC较好地耐受。这些结果表明，水体CA和pH共同影响JSC的存活、生长和生理活性。缢蛏适合在ISW中养殖。
