河川沙塘鳢早期发育过程中耗氧率及NH_3-N排泄率的变化

Variation of the Oxygen Consumption Rate and NH_3-N Excretion Rate During the Early Development of Odontobutis potamophila

为研究河川沙塘鳢(Odontobutis potamophila)在早期发育过程中的生理代谢和能量利用状况,在20.8～24.6℃的水温条件下连续测定了河川沙塘鳢早期发育过程中的耗氧率和NH3-N排泄率。结果显示,河川沙塘鳢受精卵的耗氧率较低,机体代谢维持较低的水平;随着胚胎的发育耗氧率逐渐升高,至孵化前期,耗氧率急剧增加,由0.3151μg·h-1上升至0.7055μg·h-1(p<0.05),此后耗氧率随发育呈线性增加;此外,NH3-N排泄率随发育进行整体呈上升趋势,但在胚胎发育早期没有显著性差异,眼黑色素出现期开始明显增加(p<0.05),至眼晶体形成期达到胚胎发育阶段的最大值,仔鱼刚孵出时稍有下降,之后缓慢增加,从8日龄仔鱼到16日龄稚鱼,NH3-N排泄率呈显著性增加(p<0.05),此后NH3-N排泄率维持在一个恒定水平。研究揭示河川沙塘鳢在早期发育过程中随发育时间推进,机体代谢强度逐步增加,且在发育过程中以蛋白质作为氧化底物,为胚胎发育提供了主要的能量。

To investigate the metabolism and energy utilization during the early development of Odontobutis potamophila,the oxygen consumption rate and NH3-N excretion rate were measured between 20.8 ℃ and 24.6 ℃ in this paper.The results showed that the oxygen consumption rate was very low during the early embryonic development,and the metabolism was kept at a low level.But it increased significantly at the prehatching stage from 0.315 1 μg·h-1 to 0.705 5 μg·h-1（p 0.05） .Thereafter,oxygen consumption rate increased linearly with the development of O.potamophila;In addition,the NH3-N excretion rate increased with the development of O.potamophila too,while it had no significant difference during the early embryonic development.When the embryo reached the eye pigmentation stage,the NH3-N excretion rate increased rapidly （p 0.05） and achieved maximum value of embryonic stage,yet a slightly decreased after hatching.It increased from 8 d to 16 d after hating （p 0.05） ,and then NH3-N excretion rate keeps still.The results indicated that the metabolism improved gradually during the early development of O.potamophila.As a substrate oxidation,protein provided major energy during the embryonic development.