Explore the Deep Sea

Life in the Deep


Mouthless, gutless, legless animals that rely on microbes for food.

Tubeworm basics

Tubeworms. Image courtesy T. Shank, WHOI

There are many different types of tubeworm in the ocean. Some are found at cold seeps (where chemicals leach out of the seafloor in the absence of volcanic activity), some on decomposing whale carcasses, and some near volcanoes and vents in the deep ocean.

Each individual tubeworm consists of a soft body surrounded by a tough outer tube of whitish chitin (the same substance that makes up the shells of lobsters and crabs). This tube supports the inner body and protects it from predators (in some species, the tube is leathery, in other species, it is hard). Like plants, adult tubeworms are sessile: they are anchored to one spot, although their top end can move around in the water and can be withdrawn into the tube. Some tubeworms even have "roots": extensions of their body that extend into the sediment.

Tubeworms "eat" without a mouth

Tubeworms. Image courtesy of R. Lutz, Stephen Low Productions and WHOI

Unlike most other animals, a tubeworm lacks a mouth, gut and anus. Instead, it gets its food from millions of microbes living inside it (a bit like a plant gets its food from the choloroplasts which give it its green color). The tubeworm's body reflects the symbiotic (living together) relationship it has with its microbes:

Tough cookies

Tubeworms growing near a vent. Image courtesy D. Kelley and J. Delaney

Not only can they live under immense pressures deep in the ocean, tubeworms living around volcanoes and vents can tolerate a wide range of temperatures. An individual tubeworm can often experience a range of tens of degrees over the length of its body (or a change in the same place on its body over the course of just a few seconds): from the background chill of most deep water (a few degrees above freezing), to warm fluids drifting out of vents in the seafloor.


Next: Other animals