14. Mussels
Mussels clump together around the entry points of the vents, gobbling up the bacteria swirling around in the water. They can also be found in the cracks along the sea floor doing the same thing, as the cracks also let gases seep out when the vents aren’t spewing out material.
They have a symbiotic relationship with the bacteria that live in their gills, which absorb the chemicals from the water and turn them into nutrients. When this isn’t going on, mussels can also filter out food from the water itself to survive.