Giant tube worm: (Riftia pachyptila) These annelids weren’t known prior to the 1970s. Scientists didn’t even believe they could exist. The hydrothermal vents they inhabitat were thought too extreme to support life. These vents are like underwater geysers.
Giant tube worm facts
Scorching hot water from inside the earth wells up through the ocean floor along with other chemicals. These extreme environments are situated more than a mile (1,600m) in the depths of the ocean. Temperatures at hydrothermal vents can be as warm as bath water to boiling water. The hydrothermal vents that giant tube worms inhabit are rich in sulfide and are known as “black smokers” for the dark material they produce.
It was so firmly believed that life couldn’t exist in these volcanic habitats that biologists weren’t even on the first expeditions to observe them. Now, it’s well known that hydrothermal vents support all kinds of fascinating deepsea lifeforms like giant tube worms. Giant tube worms have, so far, only been found in the Pacific Ocean.
Where do hot vent worms live?
They’re classified in the segmented worm phylum just like earthworms or leeches. They can reach more than five feet (150cm) in length which means a giant tube worm would be almost as tall as most people! These worms live inside a chitinous tube that can reach ten feet (3m) tall. This tube is made out of the same material as human fingernails and is where the giant tube worm gets its name.
When distrubed, these worms retreat into their tube for protection. Giant tube worms lack a stomach and a mouth, at least as adults. They gain nutrients through a symbiotic relationship with bacteria that live inside their bodies. These bacteria are collected during the tube worm’s early life and become trapped in the tube worm’s body – not unlike the shrimp.
Giant tube worms collect oxygen and other chemicals from the surrounding water through the blood-red, gill-like structures at the top of their body. These plumes are red because they contain a lot of hemoglobin which is a protein in red blood cells that transports the oxygen and other nutrients to the bacteria living inside the tube worm. Here, the bacteria process the sulfides taken in by the tube worm’s red filaments and release organic molecules that provide the tube worm nutrition.
Riftia pachyptila
Giant tube worms begin life as an egg. Sperm is released into the water column which meets with eggs. The eggs may also be released or they may be retained in the worm’s tube. Tubeworm larvae have a mouth, and, during the process of finding a place to settle, they eat the bacteria that will remain with them for the rest of their lives. These free living juvenile worms travel along seafloor currents.
This travel may last longer than a month and cover hundreds of miles until they find a new hydrothermal vent site on which to settle. It’s believed that giant tube worm larvae find a place to live based on the chemical composition surrounding hydrothermal vents. Here they’ll settle, much like a sessile sea pen, and may take as little as two years to reach adult size.
Giant tube worms have their giant tube to keep them safe from predators, but deep sea crustaceans may pick at their red plumes for food. They’re also at risk of shifts in the earth’s crust. An earthquake may completely cut off the flow of heated water and chemicals from below the seafloor thus rendering the entire vent dead.
Reference: Giant tube worm video
