Around hydrothermal vents at depths of more than 2,500 m, scientists have found colonies of giant tube-dwelling worms. The worms contain symbiotic prokaryotes that are able to use hydrogen sulfide as an energy source for the synthesis of organic matter from carbon dioxide. The bacteria are .

chemoautotrophic

Explanation:

The bacteria in this environment are chemoautotrophs. These are organisms that are able to manufacture their own food in the presence of chemical substances in their environment.

They are different from photoautrophs that uses light or solar energy to manufacture their food.

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs