Endoterma

Endoterma is a term used in speculative biology and some science fiction to describe organisms that sustain internal heat generation within core tissues, enabling a regulated body temperature. It is not a standard scientific term in mainstream biology, but is used to discuss alternative thermoregulatory strategies and energy budgets in hypothetical taxa.

The name derives from Greek endo- "inside" and therma/therm- "heat." The concept is positioned between ectothermy (external heat dependence) and endothermy (internal regulation at a high level), sometimes described as a gradation or distinct mechanism.

Endoterma may involve metabolic heat production localized to core organs, with regulatory circuits adjusting heat output in response to ambient conditions. It may rely on specialized mitochondria, shivering-like muscle activity, or non-shivering thermogenesis, and could imply high basal metabolic rates and significant energy demands, influencing behavior, habitat preference, and activity windows.

In fictional contexts, endotermic species might inhabit extreme climates or niche environments, leveraging internal heat to survive or outcompete ectothermic rivals. Evolutionary pathways are speculative and would require trade-offs such as greater resource requirements or heat management challenges.

In real-world science, endoterma is not established as a biological category; it may be discussed as a theoretical construct, a model for studying thermoregulation, or a narrative device. Further interdisciplinary work would be needed to formalize its definitions and implications.