When was the giant tube worm discovered at deep-sea hydrothermal vents?

Giant tube worms were first discovered by scientists in 1977 during exploration of hydrothermal vents on the deep seafloor. These animals, later identified as Riftia pachyptila, can grow more than 2 meters long and live around vent fields in the eastern Pacific. They do not have a mouth or gut as adults; instead, they house symbiotic bacteria that provide food through chemosynthesis. Their discovery became a famous example of how strange and specialized deep-ocean life can be.