QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Komai, Y. Search for Related Content PubMed PubMed Citation Articles by Komai, Y.

The Journal of Experimental Biology 204, 2999-3007 (2001)
© 2001 The Company of Biologists Limited

Direct measurement of oxygen partial pressure in a flying bumblebee

Yutaka Komai^*

ERATO, Kawachi Millibioflight Project, Park Building, 4-7-6 Komaba, Meguro, Tokyo, Japan

*Present address: Department of Vascular Physiology, Research Institute, National Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka 565, Japan (e-mail: miesha{at}tani.sd.keio.ac.jp)

Accepted June 13, 2001

The gas transport system of a bumblebee was investigated by measuring the oxygen partial pressure P_O2 in the wing muscle. In the resting bee, P_O2 showed a regular pattern of fluctuation with a typical period of 70–120s. Fluctuations in muscular P_O2 were associated with intermittent abdominal pumping. Ventilation by abdominal movements may not be necessary during rest because P_O2 is high (8.5–9.2kPa) in the anaesthetised bee. Thermal effects on muscular P_O2 were examined by cooling the bee, causing the amplitude of P_O2 fluctuations to increase. In most flight experiments, the bee started to fly after elevating muscle P_O2 by abdominal pumping; muscle P_O2 then decreased at the onset of flight. However, when a flight began without pre-flight ventilation, P_O2 increased monotonically. During flight, muscle P_O2 reached a mean level (6.36±1.83kPa) that was much higher than the lowest value recorded during discontinuous ventilation during rest. The bumblebee effectively uses abdominal movements to assist in convective gas transport not only during flight but also at rest.

Key words: oxygen microelectrode, gas transport, insect, bumblebee, Bombus hypocrita hypocruta, flight, metabolic rate.

This article has been cited by other articles:

				F.-O. Lehmann and N. Heymann Unconventional mechanisms control cyclic respiratory gas release in flying Drosophila J. Exp. Biol., October 1, 2005; 208(19): 3645 - 3654. [Abstract] [Full Text] [PDF]