Answer:
Hydro-thermal Vents.
Explanation:
'Hydro-thermal Vents' are described as the fissure or opening area in the seafloor from where the geo-thermally heated mineral-rich water gushes into seawater out of Earth's interior. These vents are often discovered near places that are active in volcanoes and in seamounts. These vents produce a dark and hot oxygen-deficient environment that is home to various communities of chemoautotrophic prokaryotes along with other organisms and unique ecosystems lying inside the deep ocean. Thus, 'hydro-thermal' vents is the answer.