pH处理时间对刺参生长、摄食及消化酶活性的影响

为研究不同pH处理时间对刺参Apostichopus japonicus Selenka生长、摄食及消化酶活性的影响,本实验以平均体重为(20.32±0.15)g的刺参为研究对象,以自然海水(pH=8.1±0.3)为对照组,设计pH=7.3,8.9两个梯度,在这两种pH条件下每日分别处理1,3,6,9,12h,随后换水并恢复正常pH,养殖实验周期为30d。研究结果表明,当养殖水pH为7.3时,刺参的特定生长率(SGR)、食物转化率(FCR)和摄食率(FR)随着处理时间的增加均呈现先上升后下降的变化趋势,当处理时间为6h时,各项指标达到峰值,显著高于对照组(P0.05);而当养殖水pH为8.9时,刺参的SGR、FCR和FR随着处理时间的增加而逐渐下降,但与对照组差异不显著(P0.05)。在养殖水pH为7.3时,刺参蛋白酶和淀粉酶活性随着pH处理时间的增加而先上升后下降,其高活性拐点出现每日6h处理组;而在养殖水pH为8.9时,蛋白酶和淀粉酶活性随着pH处理时间的增加而下降。实验结果表明,短时间的pH波动在一定程度上可促进刺参的生长和消化能力,但pH波动持续时间较长时则会抑制刺参的生长和消化。

Effects of pH with Different Durations on Growth,Feeding and Activity of Digestive Enzyme of Sea Cucumber,Apostichopus japonicus Selenka

In order to study the effects of different pH treatment time on the growth,feeding and digestive enzyme activities of Apostichopus japonicus Selenka,the average weight of sea cucumber (20.32±0.15) g was used as the research object and fed for 30 d.The sea cucumber was remained in seawater at pH 7.3 and 8.9 for 1,3,6,9,12 h respectively every day and then placed in natural seawater at pH 8.1±0.3 as the same as the control group.The results showed that when the pH value of the culture water was 7.3,the specific growth rate (SGR),food conversion rate (FCR) and feeding rate (FR) of the sea cucumber showed a trend of increasing first and then decreasing as the treatment time increased.When the treatment time was 6 h,the indexes reached the peak value,which was significantly higher than that of the control group (P<0.05).When the pH value of the culture water was 8.9,the SGR,FCR and FR of the sea cucumber gradually increased with the treatment time.There was no significant difference with the control group (P>0.05).When the pH value of the culture water was 7.3,the protease and amylase activities of sea cucumber increased first and then decreased with the increase of pH treatment time,and the high activity turning point appeared in the 6 h treatment group per day.While the culture water pH value was 8.9,the protease and amylase activity decreased with the increase of pH treatment time.The results of the experiment show that the short-term fluctuation of pH can promote the growth and digestion ability of sea cucumber to a certain extent,but if the pH fluctuation lasts for a long time,it will inhibit the growth and digestion of sea cucumber.