pH胁迫对刺参存活、生长及抗氧化酶活性的影响

Effects of pH Stress on Survival Rate, Growth and Antioxidant Enzyme Activities of the Sea Cucumber, Apostichopus japonicus Selenka

关键词:  刺参  pH  存活  生长  抗氧化酶

Key words:  Apostichopus japonicus Selenka  pH  Survival  Growth  Antioxidant enzyme

摘要:

本研究比较分析了在对照组(pH为8.4)、低pH胁迫组(pH为6.8、7.0、7.2、7.4、7.6和7.8)和高pH胁迫组(pH为8.6、8.8、9.0、9.2、9.4和9.6)的养殖水环境下，胁迫36 d对刺参(Apostichopus japonicus Selenka)存活、生长及抗氧化酶活性的影响。结果显示，不同pH对刺参存活、生长及抗氧化酶活性有显著影响。在pH 7.4~9.0范围内，刺参存活率为100%，随着pH胁迫强度和胁迫时间的增加，刺参存活率逐渐降低，当pH为6.8、7.0和9.6时，自第3天起，刺参处于过度应激状态，继而有死亡个体出现，至30 d时刺参死亡率为100%。不同pH显著影响刺参生长，刺参特定生长率随pH胁迫程度增加呈下降趋势，当pH为9.0时，刺参出现负增长。各pH胁迫组刺参超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性均高于对照组，且随pH胁迫程度的增加呈先升高后下降的变化趋势。在低pH组中，以pH=7.4时刺参SOD和CAT活性最高，分别达到(74.92±2.24) U/ml和(14.99±2.38) U/ml，显著高于对照组；而在高pH组中，SOD和CAT活性分别以pH 8.8和9.0时最高，分别达到(72.90±1.10) U/ml和(15.68±0.89) U/ml，显著高于对照组。结果表明，pH在7.4~9.0范围内是刺参存活与生长的适宜水环境，过高或过低均会引起刺参不同程度的应激反应，进而导致刺参的死亡。

Abstract:

pH is an important environmental factor affecting the survival, growth, and immunity of aquatic animals. In general, alteration of environmental conditions often results in pH fluctuation in the aquaculture water of Apostichopus japonicus Selenka. However, little is known about the physiological response of sea cucumbers under pH stress. Therefore, the survival rate, growth, and antioxidant enzyme activities of sea cucumbers (7.02±0.81 g) were analyzed under different pH (control group, pH=8.4), low pH (pH 6.8, 7.0, 7.2, 7.4, 7.6, and 7.8), high pH (pH 8.6, 8.8, 9.0, 9.2, 9.4, and 9.6)) stress for 36 days. The survival rate of sea cucumbers decreased gradually with pH intension increasing and time extension, which in the groups ranging from pH 7.4 to pH 9.0 were 100%. There appeared to be a stress response and then death of individuals in the groups of pH 6.8, 7.0 and 9.6 from the third day, in which the whole group of sea cucumbers died after 30 days. Under different pH stress, the growth of the sea cucumbers differed significantly. The specific growth rate decreased with pH intension increasing and growth was negative growth in the group of pH 9.0. The superoxide dismutase (SOD) and catalase (CAT) activity of sea cucumbers among the pH treatment groups increased and was significantly higher than those of the control group, which increased at first and then decreased with pH intension increasing. The activity of SOD and CAT of sea cucumber in low pH groups increased to (74.92±2.24) U/ml and (14.99±2.38) U/ml peaking at pH 7.4, which was significantly higher than the control group. While in high pH groups, the activity of SOD and CAT of sea cucumber increased to (72.90±1.10) U/ml and (15.68±0.89) U/ml, peaking at pH 8.8 and pH 9.0 respectively. The results indicate that the pH range from 7.4 to 9.0 is appropriate for survival and growth of sea cucumbers, otherwise stress responses and even death of sea cucumbers are imminent.