effect of nitrite on the respiratory response of grass carp ctenopharyngodon-idella (val.) with relation to chloride

Abstract

1. The oxygen consumption rates of C. idella decrease when exposed to nitrite but return to normal in the presence of chloride, reaching similar values to those of the control groups. 2. A quadratic polynomial model describes the relationship between metabolic rate, wet weight and chloride concentration in the environment, both with nitrite fixed (cL(50)-96hr=1.71mg N-NO2-/l) as chloride varied (3-6mg/l) and chloride fixed (3mg/l) as nitrite varied from lethal to sublethal concentration (1.71, 1.0, 0.5 and 0.3 mg N-NO2-/l). 3. The metabolic rate is a very useful indicator of stress caused by nitrite.