Cold seep tubeworms are fascinating animals. Unlike most animals, tubeworms do not have a mouth, gut, or anus. They completely lack a digestive system! Instead of “eating,” these animals get their food from a special symbiotic bacteria that live within their body in an organ called the trophosome. The trophosome is a large sac that is teeming with bacteria. These bacteria are chemosynthetic, so they make food by converting the seeping hydrocarbons into sugar. This food is shared with the tubeworm while the bacteria gets a safe home in return.
Cold seep tubeworms can grow quite large, with some over 10 feet long! They are also often found in large clusters with many other tubeworms. It is estimated that these worms can easily live for more than 200 years. This estimate was made by dying tubeworm clusters blue and tracking how much the worms grew over time. These measurements were then converted into growth rates which allows scientists to estimate how old the largest tubeworms are.