盐度对企鹅珍珠贝耗氧率和排氨率的影响

Effects of salinity on oxygen consumption and ammonia-N excretion rates in winged pearl oyster,Pteria penguin

研究了企鹅珍珠贝在不同盐度下（22、26、30、34、38）耗氧率和排氨率的变化规律，旨在为其养殖管理提供科学依据。所用贝的体质量规格平均为7．46g（A组）、17．61g（B组）和28．57g（C组）。结果显示，当盐度为18时企鹅珍珠贝出现死亡，在盐度22～38范围内，耗氧率和排氨率与体质量呈负幂函数关系，可表示为Y=aW^b。随着盐度的增加，企鹅珍珠贝的耗氧率也在逐步增加，当盐度为34时，耗氧率达到峰值，当盐度继续增加时，耗氧率会降低。随着盐度的增加，排氨率一直呈上升趋势，盐度为38时，排氨率最高。当盐度在22～34之间时，3种规格企鹅珍珠贝的O：N值随盐度的升高而逐步增大，在盐度34时达到最大值，然后开始下降。根据耗氧率和O：N值的变化幅度推测其适宜盐度范围为26～34。上述结果表明，企鹅珍珠贝对低盐度适应较差，在养殖生产中应根据盐度变化调整吊养水层。

The oxygen consumption and ammonia-N excretion rates of Pteria penguin under different salinities （22, 26, 30, 34 and 38） were studied in order to provide information for management of culture practice. Mean body weights of the oysters tested were 7.46 g （group A）, 17.61 g （group B） and 28.57 g （group C）. The results showed that the oxygen consumption rate and ammonia-N excretion rate in P. penguin were negatively correlated with its body weight under salinity ranging from 22 to 38, and their relationships could be expressed by a power function as Y=aWb. When salinity was lower than 18, the oysters began to die. With the increasing of salinity, the oxygen consumption rate also increased gradually. When the salinity was 34, the oxygen consumption rates reached the highest, respectively. When salinity was over 34, the oxygen rate gone down. With the increasing of salinity, ammonia excretion rates rose up. When salinity was 38, the ammonia excretion rates in the three groups reached the highest. When the salinity ranged from 22 to 34, the O： N increased with the increasing of salinity. When salinity was 34, the O：N reached the highest, then gone down when salinity was over 34. According to oxygen consumption rate and O：N ratio, its adaptive salinity range was from 26 to 34. These observations suggested that winged pearl oyster was vulnerable to low salinity, thus it was necessary to adjust the culturing water depth according to variation of salinity in the process of production.