Cyclic Gas-exchange in the Chilean Red Cricket: Inter-individual Variation and Thermal Dependence.
From: Instituto de Ecología y Evolución, Universidad Austral de Chile, Casilla 567, Valdivia, Chile. robertonespolo@uach.cl
The Journal of experimental biology
- Publish Date: Feb 2007
- ISSN: 0022-0949
- Volume: 210
- Issue: Pt 4
- Pages: 668-75
- Medium: Print
- Language: English
- Citation (JAMA): Nespolo Roberto F, Artacho Paulina, Castañeda Luis E, et al. Cyclic Gas-exchange in the Chilean Red Cricket: Inter-individual Variation and Thermal Dependence.. J. Exp. Biol. Feb 2007;210:668-75
Abstract
One of the most puzzling features of respiration in insects is cyclic gas exchange (CGE, the extreme form of discontinuous gas exchange-cycles, DGC), a periodic respiratory pattern that appeared independently several times in the evolution of arthropods. Although it is a striking feature of insects and some non-insect species, to date there is no clear knowledge of how widespread it is, or its adaptive significance. Here we show for the first time that a cricket (Cratomelus armatus) from the Stenopelmatidae family exhibits CGE. C. armatus shows a conspicuous, convective O-phase, with significantly repeatable ventilatory period and O-phase duration (intraclass correlation coefficients of 0.51 and 0.74, respectively). Also, C. armatus exhibits high variation in the CGE patterns, ranging from continuous to highly periodic records, sometimes including the classic F-phase. No record went to zero and we found significant (inverse) effects of ambient temperature on O-phase duration but not on the ventilatory period. Average VCO2 and O-phase amplitude (i.e. mean VCO2 of the peaks) increased with temperature whereas the amplitude of the interburst did not change significantly with ambient temperature. C. armatus is a species that lives below ground in humid forests, so our results support the chthonic-hygric hypothesis (i.e. facilitation of gas exchange under hypoxic and hypercapnic conditions, minimizing evaporative water loss), although this assertion needs to be confirmed statistically by a strong inference approach.
Mesh Headings (Keywords): Adaptation, Physiological, Analysis of Variance, Animals, Carbon Dioxide, Chile, Gryllidae, Respiratory Transport, Temperature, Time Factors
Check for Full Text / PubMed Unique Identifier (PMID): 17267652
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.