The giant tube worm has no eyes, mouth, or stomach.
Courtesy of Woods Hole Oceanographic Institution
In the Pacific Ocean near the Galapagos Islands, deep below the surface in the black and silent depths, there lives an animal so strange, so peculiar, so fundamentally different than all other animals that it could be an alien from another world. And in a way, it is.
Its name is Riftia pachyptila (riff-TEE-ya pak-ihp-TIL-ay) – the giant tube worm – and until 1977 scientists didn't even know it existed. Capable of growing eight feet long, the giant tube worm has no mouth, stomach, or intestines. It has no eyes, but it doesn't really need them – it lives in pitch darkness. Its soft body is housed inside a protective white tube made of chitin (kahy-tin), the same substance found in the shells of shrimp and crabs.
The worm's most distinctive feature is its bright red plume. Like a fish's gills, it is a specialized organ that absorbs chemicals from the surrounding seawater. The plume's feathery tissues are filled with a special hemoglobin, which is a protein that helps blood cells carry oxygen. Iron dissolved in the hemoglobin gives the plume its color.
Giant tube worms don't crawl like backyard worms. They anchor their bottoms to rocks and extend their red plumes into the current. Gathering in thousands atop rocky outcroppings, giant tube worms form dense colonies.