Study On Physiological Energetics Of Hyriopsis Cumingii (Lea)

The relationships between the oxygen consumption, ammonia-N excretion, ingestion rates and assimilation efficiency of Hyriopsis cumingii (Lea) and some ecological factors including body weight, temperature and density of alga were determined in the lab environments. By using static water equipments ,the components of energy budget equations of Hyriopsis cumingii(Lea) were researched too. The main results are as follows:1 , Respiration energy was converted through the oxygen consumption quantity by the formula: 1mgO₂= 14.5J. The results show that temperature and body weight influence the oxygen consumption rate of Hyriopsis cumingii(Lea) significantly , which is negatively correlated with their body weights: Y = aW^b , while positively correlated with water temperature in optimum temperature(10²6℃), and decrease obviously at 30℃.2, Excretion energy was converted through the ammonia-N excretion quantity using the formula: lmgNH4-N=19.4J. The experiments show that body weight is the important influence factor on ammonia-N excretion rate , which is negatively correlated with their body weights under various temperature, can be expressed to Y =aW^b, while positively correlated with water temperature in optimum temperature(10²6 ℃). Excretion energy is often lower than 5% in the energy allocation.3, Ingestion rate was determined according to the change of the alga density between before and after experiment. Ingestion energy was calculated by the formula: 1mgPOM=20.78J. Ingestion rate enhances with the temperature increasing in optimum temperature(10²6℃) , but too high temperature(30℃) results in its decrease , and it trends to a relatively stable value (5.32mg.h^-1) when the alga density reaches to a certain value(1.0×l0⁶ind.ml^-1). The individual ingestion rate is positively correlated with its body weight.4, Assimilation efficiency was determined through the change of POM/TPM...