Meeting Abstract
P1.16 Tuesday, Jan. 4 Ventilatory response to temperature extremes in the grass shrimp, Palaemonetes pugio. MIKA, T.L.*; REIBER, C.L.; University of Nevada, Las Vegas; University of Nevada, Las Vegas mikat@unlv.nevada.edu
Metabolic rate increases in poikilothermic animals exposed to increased temperature. The systems responsible for oxygen uptake and distribution must keep pace with this increased rate if these animals are to maintain aerobic metabolism. Analyses were performed on grass shrimp, Palaemonetes pugio, acclimated to 20° C exposed to a range of temperatures (5° – 40° C) in both normoxic and hyperoxic environments to determine response of the oxygen delivery system to this increased demand. Animals placed in a hyperoxic environment had a higher CTmax than animals in a normoxic environment, suggesting a physical limitation in oxygen delivery. Previous work has detailed the contribution of cardiac parameters to the maintenance of oxygen distribution. Current work investigates the contribution of ventilatory parameters to the oxygen delivery system. Lactate levels and oxygen consumption were measured. Ventilatory rates and an index of ventilatory flow were measured using high-speed video analysis. Ventilatory rates are approximately double the heart rate at respective temperatures and increase in a temperature dependent manner.
