|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Metabolic rate and respiratory gas-exchange patterns in tenebrionid beetles from the Negev Highlands, Israel
1 School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown 2193, South Africa,
2 Ramon Science Center, Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Mizpe Ramon 80600, Israel and
3 School of Botany and Zoology, University of Natal, Private Bag X01, Scottsville, Pietermaritzburg 3209, South Africa
*e-mail: 127fra{at}chiron.wits.ac.za
Accepted 8 January 2002
This study correlates the pattern of external gas exchange with the diel activity of nine species of tenebrionid beetle from the Negev Desert, Israel. The study species are active throughout the summer months when daytime temperatures are high and no rain falls. There were no differences in standard metabolic rate, determined by flow-through respirometry, among the nine species. All the nocturnally active beetles exhibited a form of continuous respiration, whereas the two diurnally active and one crepuscular species exhibited a cyclic form of respiration referred to as the discontinuous gas-exchange cycle (DGC). The DGCs recorded have a long flutter period consisting of miniature ventilations, and 29–48 % of the total CO2 output occurred during this period. In this study, the flutter period played an important role in the modulation of metabolic rate, in contrast to other studies in which the burst period has been shown to be important. We suggest that the long flutter period is important in reducing respiratory water loss in arid-dwelling arthropods. This study lends support to the hypothesis that discontinuous gas exchange is important in reducing respiratory water loss from beetles that need to minimise dessication because of the high water vapour pressure gradient they experience. If the use of underground burrows were responsible for the evolution of discontinuous gas exchange, then we would expect all nine tenebrionid species to use DGCs since both the nocturnally and diurnally active species bury in the sand during periods of inactivity. We conclude that the activity patterns of the beetles are more important than their habitat associations in designating the type of respiration used.
Key words: discontinuous gas-exchange cycle, diel activity, habitat association, Tenebrionidae, desert.
This article has been cited by other articles:
|
|
 |
|
  C. R. White, T. M. Blackburn, J. S. Terblanche, E. Marais, M. Gibernau, and S. L. Chown Evolutionary responses of discontinuous gas exchange in insects PNAS, May 15, 2007; 104(20): 8357 - 8361. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Marais, C. J. Klok, J. S. Terblanche, and S. L. Chown Insect gas exchange patterns: a phylogenetic perspective J. Exp. Biol., December 1, 2005; 208(23): 4495 - 4507. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. D. Duncan and M. J. Byrne The role of the mesothoracic spiracles in respiration in flighted and flightless dung beetles J. Exp. Biol., March 1, 2005; 208(5): 907 - 914. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Marais and S. L. Chown Repeatability of standard metabolic rate and gas exchange characteristics in a highly variable cockroach, Perisphaeria sp. J. Exp. Biol., December 15, 2003; 206(24): 4565 - 4574. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. L. Chown and A. L. V. Davis Discontinuous gas exchange and the significance of respiratory water loss in scarabaeine beetles J. Exp. Biol., October 15, 2003; 206(20): 3547 - 3556. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. Byrne and F. D. Duncan The role of the subelytral spiracles in respiration in the flightless dung beetle Circellium bacchus J. Exp. Biol., April 15, 2003; 206(8): 1309 - 1318. [Abstract] [Full Text] [PDF]
|
|
