Meeting Abstract

P1.75  Monday, Jan. 4  Effects of Atmospheric Oxygen on Body Size, Development Time, Growth Rate, and Tracheal Systems in Blatella germanica, the German Cockroach MUNOZ, Elyse E*; VANDENBROOKS, John M; HALE, Jennifer A; HARRISON, Jon F; Arizona State University; Arizona State University; Arizona State University; Arizona State University elyse.munoz@asu.edu

Unlike some giant insect species that lived during the high oxygen period of the Paleozoic era, maximum cockroach body size has remained relatively unchanged over the last 300 million years. To better understand this phenomenon, 350 Blattela germanica were reared in seven different oxygen levels ranging from 12%-40% from hatch to adulthood. Adult mass, growth rate, and development were measured. Mild hyperoxia (up to 31% oxygen) showed no effect on body size, while oxygen levels above 31% reduced body size and growth rates, though extended development times. Hypoxia reduced size, growth rate and extended development time. Thus 21% oxygen is the optimal condition for Blatella germanica. The lack of a positive effect of hyperoxia on size may explain why historical hyperoxia did not stimulate gigantism in this group of insects. A subset of these cockroaches (12 from each oxygen) were imaged at Argonne National Labs using phase contrast x-ray synchrotron imaging, with emphasis on the dimensions of their leg tracheal system which are currently being analyzed. This research was partially supported by NSF EAR07463522 to JFH.