Hydrothermal Vent and Cold Seep Worms: Vestimentifera

Hydrothermal vent species mature within a few years, but those living near cold seeps may take 100 years or more to reach adulthood.

There is no contact between males and females. Males release sperm or sperm packets into the water, and the sperm find their way into the tubes of the females. Large numbers of eggs are fertilized inside or just outside the female's reproductive ducts and released into the water. The young larvae (LAR-vee) swim with the help of a band of hairlike cilia (SIH-lee-uh) on the front of their bodies. In order to feed, the larvae take in bacteria that eventually settle in their bodies as they grow. These mutualistic (MYU-chu-eh-LIH-stihk) organisms benefit from their relationship with each other.