1. Vent Tube Worm
These bizarre red-and-white worms can be two metres (six feet) tall and have no mouth or stomach. They rely on bacteria living inside them to convert chemicals into food.
3. Vent crab
Adult vent crabs have eyesight similar to military night-vision goggles to help them see at ocean depths of 2.7 kilometres (1.7 miles). They are the top predators around vents.
4. Vent shrimp
These blind invertebrates have simple light detectors on their backs instead of eyes, which may work like infrared heat vision to help them spot glowing vents in the gloom.
5. Scaly-foot gastropod
The metal scales protecting these snails from crab attack are unique – other snails have soft, slimy feet. Their body armour could inspire designs of motorcycles or flak jackets.