You are in the accessibility menu

Please use this identifier to cite or link to this item: http://acervodigital.unesp.br/handle/11449/21149
Title: 
Seasonal changes in daily metabolic patterns of tegu lizards (Tupinambis merianae) placed in the cold (17 degrees C) and dark
Author(s): 
Institution: 
  • Univ British Columbia
  • Universidade Estadual Paulista (UNESP)
  • Univ Aarhus
ISSN: 
1522-2152
Abstract: 
Oxygen consumption rate was measured continuously in young tegu lizards Tupinambis merianae exposed to 4 d at 25 degrees C followed by 7-10 d at 17 degrees C in constant dark at five different times of the year. Under these conditions, circadian rhythms in the rate of oxygen consumption persisted for anywhere from 1 d to the entire 2 wk in different individuals in all seasons except the winter. We also saw a progressive decline in standard oxygen consumption rate (at highly variable rates in different individuals) to a very low rate that was seasonally independent (ranging from 19.1 +/- 6.2 to 27.7 +/- 0.2 mL kg(-1) h(-1) across seasons). Although this degree of reduction appeared to take longer to invoke when starting from higher metabolic rates, tegu lizards reduced their metabolism to the low rates seen in winter dormancy at all times of the year when given sufficient time in the cold and dark. In the spring and summer, tegus reduced their standard metabolic rate (SMR) by 80%-90% over the experimental run, but only roughly 20%-30% of the total fall was due to the reduction in temperature; 70%-80% of the total fall occurred at constant temperature. By autumn, when the starting SMR on the first night at 25 degrees C was already reduced by 59%-81% (early and late autumn, respectively) from peak summer values, virtually all of the fall (63%-83%) in metabolism was due to the reduction in temperature. This suggests that the temperature-independent reduction of metabolism was already in place by autumn before the tegus had entered winter dormancy.
Issue Date: 
1-Mar-2008
Citation: 
Physiological and Biochemical Zoology. Chicago: Univ Chicago Press, v. 81, n. 2, p. 165-175, 2008.
Time Duration: 
165-175
Publisher: 
Univ Chicago Press
Source: 
http://dx.doi.org/10.1086/524148
URI: 
http://hdl.handle.net/11449/21149
Access Rights: 
Acesso restrito
Type: 
outro
Source:
http://repositorio.unesp.br/handle/11449/21149
Appears in Collections:Artigos, TCCs, Teses e Dissertações da Unesp

There are no files associated with this item.
 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.