The Comparative Study on Two Measuring Methods of Respiratory Metabolism in Fish

It is an important index of physiology of fish to respiratory metabolism level.There is the important signification for studying physiology of fish to set up accurate measurement method. Results indicated that the respiratory metabolism was investigated comparatively at different temperature by close-flow type and open still water type.When temperature was lower, oxygen consumption rate of trail fish was relatively lower.There was less difference by two methods.With temperature rising,the level of metabolism of the fish also raised.So the result demonstrated certain difference.This represented that oxygen consumption rate was higher by close-flow type,and oxygen consumption rate rose sharply,having an obvious peak at 28℃;the oxygen consumption rate rose slowly by open-still type,and having no distinct peak.The results were lower obviously by open-still type than those by close-flow type.The difference may be induced that because pressure difference of oxygen in the water and oxygen in the air became large,with the consumption of the oxygen in the water,the quantity of oxygen in the air entering the water by the interface was large at open-still type condition.Comparatively speaking,it is more accurate to measure oxygen consumption rate by close-flow type.