ISSN:
1573-8477
Keywords:
animal coloration
;
body temperature
;
ectotherm
;
evolution
;
Orthoptera
;
poly-morphism
;
Tetrix subulata
;
thermoregulation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Ectothermic animals rely on external heat sources and behavioral thermoregulation to control body temperature, and are characterized by possessing physiological and behavioural traits which are temperature dependent. It has therefore been suggested that constraints on the range of body temperatures available to individuals imposed by phenotypic properties, such as coloration, may translate into differential fitness and selection against thermally inferior phenotypes. In this paper, I report an association between thermal preferences and thermal capacity (the ability to warm up when insolated) across different genetically coded color morphs of the pygmy grasshopper Tetrix subulata. Data on behavioral thermoregulation of individuals in a laboratory thermal gradient revealed a preference for higher body temperatures in females than in males, and significant variation among colour morphs in preferred body temperatures in females, but not in males. The variation in females was in perfect accordance with estimates of morph-specific differences in thermal capacity. Thus, dark morphs not only attain higher temperatures when exposed to augmented illumination, but also prefer higher body temperatures, compared to paler morphs. This intra-population divergence probably reflects an underlying variation among colour morphs in temperature optima, and is consistent with the notion that coloration, behaviour and physiology evolve in concert.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1011024320725
