Hypoxia-induced compression in the tracheal system of the tobacco hornworm caterpillar, Manduca sexta.

ABSTRACT: Abdominal pumping in caterpillars has only been documented during molting. Using synchrotron X-ray imaging in conjunction with high-speed flow-through respirometry, we show that Manduca sexta caterpillars cyclically contract their bodies in response to hypoxia, resulting in significant compressions of the tracheal system. Compression of tracheae induced by abdominal pumping drives external gas exchange, as evidenced by the high correlation between CO2 emission peaks and body movements. During abdominal pumping, both the compression frequency and fractional change in diameter of tracheae increased with body mass. However, abdominal pumping and tracheal compression were only observed in larger, older caterpillars (>0.2 g body mass), suggesting that this hypoxic response increases during onto

SUBMITTER: Greenlee KJ 

PROVIDER: S-EPMC3667129 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature