Ectotherm
Thermoregulation in animals |
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An ectotherm (from the
Some of these animals live in environments where temperatures are practically constant, as is typical of regions of the abyssal ocean and hence can be regarded as
In contrast to ectotherms, endotherms rely largely, even predominantly, on heat from internal metabolic processes, and mesotherms use an intermediate strategy.
As there are more than two categories of temperature control utilized by animals, the terms warm-blooded and cold-blooded have been deprecated as scientific terms.
Adaptations
Various patterns of behavior enable certain ectotherms to regulate body temperature to a useful extent. To warm up, reptiles and many insects find sunny places and adopt positions that maximise their exposure; at harmfully high temperatures they seek shade or cooler water. In cold weather, honey bees huddle together to retain heat. Butterflies and moths may orient their wings to maximize exposure to solar radiation in order to build up heat before take-off.
In addition to behavioral adaptations, physiological adaptations help ectotherms regulate temperature. Diving reptiles conserve heat by heat exchange mechanisms, whereby cold blood from the skin picks up heat from blood moving outward from the body core, re-using and thereby conserving some of the heat that otherwise would have been wasted. The skin of bullfrogs secretes more mucus when it is hot, allowing more cooling by evaporation.[citation needed]
During periods of cold, some ectotherms enter a state of torpor, in which their metabolism slows or, in some cases, such as the wood frog, effectively stops. The torpor might last overnight or last for a season, or even for years, depending on the species and circumstances.
Owners of reptiles may use an ultraviolet light system to assist their pets' basking.[10]
Pros and cons
Ectotherms rely largely on external heat sources such as
Because ectotherms depend on environmental conditions for body temperature regulation, as a rule, they are more sluggish at night and in early mornings. When they emerge from shelter, many
In ectotherms, fluctuating ambient temperatures may affect the body temperature. Such variation in body temperature is called poikilothermy, though the concept is not widely satisfactory and the use of the term is declining. In small aquatic creatures such as Rotifera, poikilothermy is practically absolute, but other creatures (like crabs) have wider physiological options at their disposal, and they can move to preferred temperatures, avoid ambient temperature changes, or moderate their effects.[2][12] Ectotherms can also display the features of homeothermy, especially within aquatic organisms. Normally their range of ambient environmental temperatures is relatively constant, and there are few in number that attempt to maintain a higher internal temperature due to the high associated costs.[13]
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American alligators basking in the sunlight around noon
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Junonia lemonias basking under the sun
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A 1.8m southern black racer basking in the Inverness, Florida, sunshine on a cool morning
References
- ^ "Ectotherm | Definition, Advantages, & Examples | Britannica".
- ^ ISBN 978-0412403507
- ISBN 978-0-226-73538-2.)
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: CS1 maint: multiple names: authors list (link - ISBN 978-0-471-29505-1.)
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: CS1 maint: multiple names: authors list (link - S2CID 85188708.
- from the original on 2017-11-15.
- .
- ^ Loewy, Katrina. "Life History Traits And Rearing Techniques For Fall Webworms (Hyphantria Cunea Drury) In Colorado" (PDF). Journal of the Lepidopterists' Society. Archived from the original (PDF) on 2018-05-06. Retrieved 2017-11-15.
- ISSN 1600-0706.
- ^ "Best Reptile UVA/UVB Light Bulbs (Reviewed + Best Deals From Amazon) – BuddyGenius". buddygenius.com. 4 January 2018. Archived from the original on 17 January 2018. Retrieved 6 May 2018.
- PMID 22877672.
- .
- ^ Willmer, Pat; Stone, Graham; Johnston, Ian. Environmental Physiology of Animals. Hoboken: Wiley, 2009. Ebook Library. Web. 01 Apr. 2016.