spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online January 16, 2009
Journal of Experimental Biology 212, 424-428 (2009)
Published by The Company of Biologists 2009
doi: 10.1242/jeb.024091
This Article
Right arrow Summary Freely available
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Related articles in JEB
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Contreras, H. L.
Right arrow Articles by Bradley, T. J.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Contreras, H. L.
Right arrow Articles by Bradley, T. J.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

Metabolic rate controls respiratory pattern in insects

H. L. Contreras* and T. J. Bradley

University of California Irvine, Ecology and Evolutionary Biology, 5205 McGaugh Hall, Irvine, CA 92697, USA


Figure 1
View larger version (22K):
[in this window]
[in a new window]

  		Fig. 1. Examples of (A) discontinuous, (B) cyclic and (C) continuous respiration in male Rhodnius prolixus. The experimental trial lasted 55 min with three 5 min baselines (where an empty chamber was read) at 0–5 min, 25–30 min and 50–55 min (blue line) and two 20 min experimental readings at 5–25 min and 30–50 min (black line). CO2 bursts were observed in all treatments although the overall pattern seemed to differ as metabolic rate increased.

 

Figure 2
View larger version (28K):
[in this window]
[in a new window]

  		Fig. 2. Four experimental traces for a single insect under (A) dry unfed, (B) dry fed, (C) humid unfed and (D) humid fed conditions. The experimental trial lasted 55 min with three 5 min baselines (where an empty chamber was read) at 0–5 min, 25–30 min and 50–55 min. CO2 bursts were observed in all treatments although the overall pattern seemed to differ between fed and unfed individuals. Bursts were defined as values above twice the VCO2 average (dashed line) for that trial, which were preceded or followed by at least a minute of values falling below the VCO2 average (red solid line).

 

Figure 3
View larger version (6K):
[in this window]
[in a new window]

  		Fig. 3. A diagrammatic representation of the PO2 in the tracheal lumen of an insect during the open (O), closed (C) and flutter (F) phases of the discontinuous gas-exchange cycle (DGC). The partial pressure of O2 increases during the open phase and decreases during the closed phase. The closed phase is terminated when the partial pressure of oxygen reaches a critically low level (3.5% in this example). During the flutter phase the insect regulates the spiracles to maintain a steady but low PO2. When the insect is experiencing a low metabolic rate (A) the closed phase is relative long. At higher metabolic rates (B) the closed phase is shorter because the oxygen present in the tracheae and tissues is more rapidly depleted.

 

Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?



© The Company of Biologists Ltd 2009