Dissertation Research: Mechanisms and Significance of Ontogenetic Changes in Respiratory Function During Insect Locomotion

Arizona State University, Scottsdale AZ

Investigators

Abstract

Dissertation Research: Mechanisms and Significance of Ontogenetic Changes in Respiratory Function During Insect Locomotion Jon Harrison and Scott Kirkton The goal of this research is to examine how body size affects the respiratory physiology of active insects. Initial results show that larger/older grasshoppers fatigue quicker during repeated jumping, which suggests possible problems with oxygen delivery to the muscle. This project utilizes American locusts (Schistocerca americana) to determine how structural changes in both the respiratory tracheal system and the jumping muscle vary with body size during development. The tracheal structure will be measured using light and electron microscopy, while the leg muscle metabolic biochemistry will be measured using enzymatic assays. The amount of oxygen consumed during jumping will be measured for the whole animal using flow-through respirometry and leg muscle oxygen levels will be measured with electron paramagnetic resonance. The results of this project will help understand the general relationship between body size and tracheal function and provide a test of the hypothesis that gigantic insects of the Paleozoic Era were made possible by increased atmospheric oxygen levels.