Validating a Diabetic Glucose Meter to Assess Walleye Glucose Concentrations

Abstract

Fisheries biologists have long been interested in monitoring stress in fish by observing changes in glucose concentrations. However, measuring glucose in the field is difficult, time consuming, and expensive. Diabetic glucose meters may provide a rapid, cost-effective monitoring tool that can be used in the field or laboratory, but they need to be evaluated for a particular species before they can be integrated into monitoring programs. Our objective was to evaluate the FreeStyle Lite diabetic glucose meter across a broad range of glucose concentrations exhibited by advanced fingerling Walleyes Sander vitreus (197 ± 20 mm [mean ± SD]; 73.5 ± 18.8 g). Eleven groups of five advanced fingerling Walleyes were chased for up to 10 min with a dip net, sequentially removed at 5-min intervals, and blood samples were collected. Glucose concentrations were determined using both the FreeStyle Lite diabetic glucose meter and the traditional colorimetric laboratory method for individual samples. The percent difference in glucose concentrations (glucose meter minus colorimetric laboratory glucose) was nearly always (95% of observations) within 2 SDs of the average glucose concentration reported by both methods. Costs associated with the use of the glucose meter as well as the required sample size were less for the glucose meter than the colorimetric laboratory method. Combined, results from this study suggest the glucose meter detected changes in glucose concentrations of advanced fingerling Walleyes and offers an alternative method that is cheaper, faster, and less invasive than the traditional colorimetric laboratory method.

Received December 2, 2016; accepted March 20, 2017 Published online May 24, 2017

ACKNOWLEDGMENTS

This research was supported through an Iowa State University Presidential Wildlife Funding grant. J. Morris and two anonymous reviewers provided useful comments to a previous version of this manuscript. We thank the Iowa Department of Natural Resources Rathbun Fish Hatchery staff for providing the fingerling Walleyes and facilities for this experiment. The use of trade names or products does not imply endorsement by Iowa State University or Iowa Department of Natural Resources. The previously described research was completed in accordance with Iowa State University’s institutional animal care and use committee (IACUC) permit 7-15-8051-I.