Blood sugar as an indicator of stress in the freshwater fish, Labeo capensis (Smith)

Abstract

Factors involved in the determination of the blood sugar level of L. capensis have been studied. The stress of capture and transportation produces a marked increase in the blood sugar concentration. The relationship between blood sugar concentration and oxygen saturation of water and between blood sugar concentration and ammonium ion concentration was also investigated. Increases in ammonium ion concentration and decreases in oxygen saturation of water produce increases in the blood sugar concentration. The results are discussed in relation to the phenomenon of ‘asphyxiation hyper‐glycemia’.