chemosynthesis
It’s like photosynthesis but with heat (and maybe so other type of inoganic stuff idk) instead of sunlight. It typically appears in the abyss or other places with not a lotta sunlight and there’s this neat article somewhere that I found actually explaining it instead of using sciency words.
“Tube Worms use chemosynthesis to absorb the heat of underwater volcanoes to thrive in the abyss”
Chemosynthesis
The Opposite Of Photosynthesis
If You Know What Photosynthesis Is. Chemosynthesis Is The Opposite.(: