from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun An organism that depends on external sources for its body heat.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun biology a cold-blooded animal which regulates its body temperature by exchanging heat with its surroundings

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun an animal whose body temperature varies with the temperature of its surroundings; any animal except birds and mammals


Sorry, no etymologies found.


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  • That's why several zoos are participating in a sort of sperm bank for snot otters, says Dale McGinnity, ectotherm curator for the Nashville Zoo.

    Green Movement's New Mascot: the Slimy Snot Otter Leslie Eaton 2011

  • Whereas an endotherm expends a tremendous amount of energy just to maintain a constant body temperature, a cold ectotherm can pass months at a time requiring little food or oxygen.

    Amphibian 2008

  • Endotherms differ from an ectotherm because they typically have core temperatures above that of the surrounding environment, whereas the core temperatures of ectotherms depend on external sources of heat – primarily from solar radiation.

    Endotherm 2008

  • Turtle • Endotherm / ectotherm - Migration to northern water • Problems - Stagnant ocean -

    Recently Uploaded Slideshows 2009


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  • "Commonly known as being cold-blooded and in need of sunshine, the world's fish and reptiles may be struggling to keep cool in the future. The finding raises concerns about how ectotherms - animals that regulate their body heat using air temperature - will cope in a warmer world predicted by climate change. Writing in today's issue of Proceedings of the National Academy of Sciences, a team of Australian and US researchers say the impact of climate change on ectotherms will depend on how global warming-induced changes in habitat alter the ability to access shade."

    - Dani Cooper, Cold comfort for reptiles in warmer world

    February 19, 2009