盐度和pH对细角螺耗氧率和排氨率的影响

Effects of Salinity and pH on Oxygen Consumption and Ammonia Excretion of Whelk Hemifusus ternatanus

在实验室条件下测定16、20、24、28、32、36、40等盐度和pH 7.0、8.0、9.0等pH水平下细角螺（Hemifusus ternatanus）成贝的耗氧率和排氨率。结果显示,随盐度升高,细角螺的耗氧率呈先升高后下降趋势,盐度28和32时的耗氧率高于其他盐度处理组,差异有统计学意义（P〈0.05）;随着盐度降低,排氨率在盐度28-20时升高,差异有统计学意义（P〈0.05）,盐度24、20组差异有统计学意义（P〈0.01）,至盐度16降低,差异有统计学意义（P〈0.01）,且出现死亡。pH 7.0时细角螺的耗氧率低于pH 8.0（P〈0.01）和pH 9.0处理组（P〈0.05）;pH 9.0组排氨率高于pH 8.0组,差异有统计学意义（P〈0.01）。氧氮比值显示,细角螺在适宜条件下更多依靠脂肪和碳水化合物维持机体代谢,在盐度和pH胁迫条件下消耗机体的蛋白质来维持机体生理代谢需要。细角螺可适应一定范围的盐度和pH变化,盐度16可能是其生长存活的最低盐度。

The oxygen consumption and ammonia excretion rates of adult whelk Hemifusus ternatanus at different salinity（ 16, 20, 24, 28, 32, 36, 40） and pH levels（ 7.0, 8.0, 9.0） were measured in the lab. The results showed that the oxygen consumption rate of the whelk first increased and then decreased with the increasing of the salinity. And the whelks in group of salinity 28 and 32 presented significant higher oxygen consumption rates than those in other treatment groups（P〈0.05）. With the decline of salinity, the ammonia excretion rate was significantly increased in group of salinity 28, 24 and 20（P〈0.05）, and presented an statistical difference from the group of 32, 36 and40 at salinity 24（P〈0.01）, and then significantly decreased at salinity 16（P〈0.01）, and then some whelks died. The oxygen consumption rate of whelks at pH 7.0 was significantly lower than that of those at pH 8.0（P〈0.01） and pH 9.0（P〈0.05）. At pH 9.0, the ammonia excretion rate was significantly increased（P〈 0.01）. The ratio of atomicity O/N suggested that under suitable conditions, the whelk mainly relied on fat and carbohydrate to maintain body metabolism, but the whelk would consume protein to meet the energy needs of body when they were under stresses of salinity and pH. The experiment showed that H. ternatanuscould could adapt to salinity and pH changes in a limited range, and salinity 16 might be the minimum for its growth and survival.