|
Title
|
|
|
|
Trade-offs between speed and endurance in the frog **Xenopus laevis** : a multi-level approach
|
|
|
Author
|
|
|
|
|
|
|
Abstract
|
|
|
|
| One of the most interesting trade-offs within the vertebrate locomotor system is that between speed and endurance capacity. However, few studies have demonstrated a conflict between whole-animal speed and endurance within a vertebrate species. We investigated the existence of trade-offs between speed and endurance capacity at both the whole-muscle and whole-animal levels in post-metamorphs of the frog Xenopus laevis. The burst-swimming performance of 55 frogs was assessed using a high-speed digital camera, and their endurance capacity was measured in a constant-velocity swimming flume. The work-loop technique was used to assess maximum power production of whole peroneus muscles at a cycle frequency of 6 Hz, while fatigue-resistance was determined by recording the decrease in force and net power production during a set of continuous cycles at 2 Hz. We found no significant correlations between measures of burst swimming performance and endurance capacity, suggesting that there is no trade-off between these two measures of whole-animal performance. In contrast, there was a significant negative correlation between peak instantaneous power output of the muscles at 6 Hz and the fatigue-resistance of force production at 2 Hz (other correlations between power and fatigue were negative but non-significant). Thus, our data support the suggestion that a physiological conflict between maximum power output and fatigue resistance exists at the level of vertebrate muscles. The apparent incongruence between whole-muscle and whole-animal performance warrants further detailed investigation and may be related to factors influencing both whole-muscle and whole-animal performance measures. |
|
|
|
Language
|
|
|
|
English
|
|
|
Source (journal)
|
|
|
|
The journal of experimental biology. - London, 1930, currens
|
|
|
Publication
|
|
|
|
London
:
2002
|
|
|
ISSN
|
|
|
|
0022-0949
[print]
1477-9145
[online]
|
|
|
Volume/pages
|
|
|
|
205
:8
(2002)
, p. 1145-1152
|
|
|
ISI
|
|
|
|
000175323300010
|
|
|
Full text (publisher's version - intranet only)
|
|
|
|
|
|