Ectothermic

Infrared image : an ectothermic reptile eats an endothermic mouse

Behaviors such as sunbathing can cause ectothermal lizards to heat up significantly

In biology, animals whose body temperature is completely dependent on the ambient temperature and is normally not influenced by their metabolism are referred to as ectothermic (synonyms, alternating warmth , poikilothermic ) . Therefore ectothermic animals are also called cold blood animals . The opposite property is called endothermic or uniformly warm or homoiothermic . The vast majority of living things are not necessarily endothermic.

• In deep-sea fish , the body temperature depends solely on the outside temperature. Since the water in the deep sea always has a temperature of 4 ° C, the fish found there always have this temperature; but since they cannot regulate them, they are not classified as homoiothermic but as ectothermic.

• All invertebrates , fish , amphibians and reptiles are ectothermic or poikilothermic . Your body temperature depends solely on the outside temperature. At most, it can be regulated to a certain extent through their behavior (e.g. sunbathing, retreating into a hiding place, high level of physical activity). For example, some insects warm up for a few minutes on cool mornings due to muscle tremors in order to be able to fly.

• Some endothermic animals temporarily lower their core body temperature, so that less energy is used during the cold season. The core body temperature during this hibernation is, unlike in winter rigor , controlled by the hypothalamus and, in the event of disturbances, is immediately raised to normal temperature by the release of norepinephrine .

Web links

• The term ektotherm www.wasser-wissen.de

Individual evidence

1. ↑ David J. Randall: Animal Physiology. Georg Thieme Verlag, 2002, ISBN 978-3-136-64004-3 , pp. 792ff.