Exchanges of oxygen, carbon dioxide, nitrogen and water in the caecilian Dermophis mexicanus |
| |
Authors: | D F Stiffler C R Talbot |
| |
Institution: | (1) Biological Sciences Department, California State Polytechnic University, Pomona, CA 91768, USA e-mail: dfstiffler@csupomona.edu Tel.: +1-909-8694061; Fax: +1-909-8694078, US;(2) Department of Biology, California State University, San Bernardino, CA 92407, USA, US |
| |
Abstract: | Oxygen consumption was measured in five Dermophis mexicanus and averaged (±SEM) 0.047 ± 0.004 ml O2 g−1 h−1. Carbon dioxide production averaged 0.053 ± 0.005 ml CO2 g−1 h−1 in the same five animals 1 week later. This metabolic rate is similar to metabolic rates of other Gymnophionans but lower
than metabolic rates reported for Anurans and Urodeles. Total nitrogen excretion averaged 1.37 μmol N g−1 h−1 which is higher than that found for other amphibians. Of this, 82.5% (1.13 μmol N g−1 h−1) was in the form of urea while 17.5% (0.24 μmol N g−1 h−1) was in the form of NH3 + NH+
4. Such ureotelism is typical of terrestrial amphibians like D. mexicanus. Osmotic water flux averaged 0.0193 ml g−1 h−1 in control (sham injected) animals and was not significantly altered by injection of either arginine vasotocin or mesotocin.
This osmotic flux is similar to osmotic fluxes found for other terrestrial amphibians. The combined data suggest that metabolism
in D. mexicanus is, like most other Gymnophionans, lower than other amphibians. The high rates of nitrogen (especially urea) excretion suggests
that this fossorial animal accumulates urea like other burrowing amphibians.
Accepted: 27 June 2000 |
| |
Keywords: | Ammonotelism Ureotelism Osmotic flux Arginine vasotocin Mesotocin |
本文献已被 PubMed SpringerLink 等数据库收录! |
|