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How Volcano Vent Tubeworms Work

        Science | Oceanography

Of Worms and Subs
In the 1970s, the adorable Alvin submersible played a key role in helping scientists discover tubeworms.
In the 1970s, the adorable Alvin submersible played a key role in helping scientists discover tubeworms.
Bettmann/CORBIS

Let's start by talking about Alvin. Not the beloved 70's toy aardvark, and not that singing chipmunk either, but the three-person, robotic-armed, deep-sea submersible that has starred in a series of spectacular discoveries on the ocean floor since the mid-1960s. Alvin's most famous find was the wreck of the Titanic back in the 1980s.

Nearly a decade earlier, in 1977, scientists were piloting Alvin around a vent in the sea floor in the neighborhood of the Galapagos Islands when they stumbled upon, or rather floated over, a field of very weird beings. They had expected to see nothing but a barren seascape. Instead, their headlights picked up a lush oasis of hitherto unseen organisms. The most prominent new species was our friend the tubeworm [source: Trivedi].

This discovery was like a bomb dropped on a whole set of biological assumptions. These creatures were living in an environment where nobody thought life was possible. At the bottom of our familiar land-dwelling food chain are photosynthetic plants that eat sunlight. So how can anything live where there's no sun?

Different world, different food chain. Instead of a photosynthetic foundation to the local diet, there's a chemosynthetic one. That means the organisms at the bottom of the food chain on the bottom of the ocean are eating chemicals. In fact, as Tim Shank, one of the leading researchers in the field of deep-sea vent life has said, the vents host the largest "chemosynthetic community" on Earth [source: Nevala]. And that community has been around for a long time. The fossil record shows that the ancestors of modern tubeworms and their vent neighbors were getting their start at the same time as the dinosaurs [source: Shank].

But the giant tubeworms aren't the only worms down there. Keeping them company are little straw-length guys called Jericho worms, bristly orange worms, wriggling benthic worms and red palm worms the size of your finger [source: Stover].

Interestingly, while there are tubeworms at vents all over the Pacific Ocean, there are none in the Atlantic where creatures like deep-sea shrimp dominate the scene. Nobody knows for sure why this is, but there are many factors that could be behind it. One theory suggests that when the Atlantic Ocean was forming, it was extremely salty, a condition that shrimp tolerate better than tubeworms. Once the shrimp were firmly established, they never let the tubeworms move in. That's because shrimp scrape the surfaces around vents for the bacteria they like to dine on, meaning they probably eat up any tubeworm larvae before they have a chance to grow [source: Shank].