Also found in: Thesaurus, Medical, Encyclopedia, Wikipedia.


An organism, such as a fish or reptile, having a body temperature that varies with the temperature of its surroundings.

[Greek poikilos, spotted, various; see peig- in Indo-European roots + -therm.]

poi′ki·lo·ther′mi·a (-thûr′mē-ə), poi′ki·lo·ther′my (-thûr′mē) n.
poi′ki·lo·ther′mic (-mĭk) adj.


(Animals) an organism with poikilothermic qualities
(Zoology) a variant form of poikilothermic
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.poikilotherm - an animal whose body temperature varies with the temperature of its surroundings; any animal except birds and mammals
animal, animate being, beast, creature, fauna, brute - a living organism characterized by voluntary movement
References in periodicals archive ?
marinum can infect poikilotherm animals in addition to aquatic animals.
Effects of temperature on rates in poikilotherm nervous systems: evidence from the calling songs of meadow katydids (Orthoptera: Tettigoniidae: Orchelimum) and reanalysis of published data.
Among reported poikilotherm predators of Steller sea lions, only the Pacific sleeper shark (Somniosus pacificus) is known to have body core temperatures that are near ambient.
Cadmium effects on mitochondrial function are enhanced by elevated temperatures in a marine poikilotherm, Crassostrea virginica Gmelin (Bivalvia: Ostreidae).
Their analysis demonstrates that cold exposure of a poikilotherm that naturally experiences environmental cooling involves the regulation of a very large number of genes.
Lindsey, "Body sizes of poikilotherm vertebrates at different latitudes," Evolution, vol.
The word homeotherm is used to describe the opposite of poikilotherm. Poikilothermic animals' body temperature varies in accordance with the ambient temperature of their environment.
(52) It is noteworthy that both the mammalian as well as the bird embryo have poikilotherm metabolism till birth (homoeothermic condition is provided by parent organism).