Evaluation of simple instruments for the measurement of blood glucose and lactate, and plasma protein as stress indicators in fish

Responses of rainbow trout, Oncorhynchus mykiss, to handling and confinement stress were used to validate the efficacy of portable instruments for measuring blood glucose and lactate, and plasma protein. Glucose and lactate increased with time and showed good linear correlation with time after disturbance. The Advantage(TM) blood glucose and Accusport(TM) lactate meters were similarly correlated, except that values were consistently lower than those obtained by established laboratory techniques. Refractometry gave higher plasma protein values than results from biuret reagent but with excellent correlation. These findings indicate a potential role for portable instruments in field and hatchery locations where relative rather than absolute values may be used to evaluate responses to stressors.