the.com/ectotherm
A creature that outsources its thermostat to the entire planet.
means An animal whose body temperature is set by its surroundings rather than its own metabolism — what we loosely call cold-blooded.
from Built from Greek ektos, 'outside,' plus thermē, 'heat' — literally 'outside-heat,' naming the fact that the warmth comes from out there, not in here. It's a 20th-century scientific coinage, part of a tidy pair with 'endotherm' (endon, 'within'), minted to replace the older and clumsier 'cold-blooded,' which was never quite true since a basking lizard's blood can run plenty warm.
- fuel economy
- Needs roughly a tenth the food of warm-blooded animals
- sun powered
- Basking is literally how they charge up
- cold shutdown
- Too chilly and their bodies simply stop working
- size kings
- All largest land animals ever were ectotherms
- frozen frogs
- Some survive winter with ice inside them
komodo dragon — indonesian reptile that basks in sun to raise body temperature before hunting, weighs up to 366 pounds
leatherback sea turtle — cold-water ocean reptile that maintains elevated body temperature through metabolic heat retention in deep dives
great white shark — fish that relies on environmental water temperature, found hunting in waters from 12-24°c