Meeting Abstract

P2.111  Jan. 5  Normoxic Drosophila larvae like it deeper ALBERT, T.W.*; PIERCE, N.; KLOK, C.J.; HARRISON, J.F.; Arizona State University; Arizona State University; Arizona State University; Arizona State University toddwalbert@yahoo.com

Rearing in hypoxic atmospheres decreases the size of fruitflies and other insects. The mechanisms responsible for this effect remain unclear. One way that varying atmospheric oxygen levels may influence body size in Drosophila is by affecting the oxygen gradient within the nutritional medium in which Drosophila larvae are reared. As larvae progress deeper into the medium, less oxygen may be available for respiration, thus hypoxic atmospheres may limit the depth at which larvae can feed. To test this hypothesis, Drosophila larvae were reared in 10% or 21% (normoxic) oxygen atmospheres in glass containers (1 mm x 20 mm x 75 mm) that forced larvae to tunnel in only two dimensions, allowing us to quantify their tunneling behavior. Images of the containers were taken twice a day and analyzed for digging depth, tunnel size, and total volume of food eaten. Hypoxic larvae averaged 12% lighter than normoxic-reared larvae, and consumed approximately 14% less food. Tunnel depths for normoxic-reared larvae were approximately 50% deeper than for hypoxic-reared larvae. Thus hypoxia caused larvae to tunnel more extensively in the upper regions of the media to obtain their food. These data demonstrate that atmospheric oxygen level influences larval feeding behavior. If restriction of foraging to shallower depths provides lower quality food (perhaps due to drying of the media, oxidation of the media, or mixing media with feces), then this oxygen-limitation on foraging depth may restrict larval growth. This research was funded by NSF grant IBN-0419704 awarded to JFH.