Sand Worms Clam Worms and Tubeworms: Polychaeta

Physical characteristics: The body of a fire worm is flat and long, measuring up to 4.7 to 5.5 inches (120 to 140 millimeters). The head has one pair of eyes, tentacles, and a pair of fleshy lobes associated with the mouth. The fleshy side flaps are well developed and have stiff, hollow bristles filled with defensive toxins. The bristles easily break off and cause a burning, stinging sensation when they come into contact with human skin. The fire worm also has blood red gill tufts, a part of the breathing system.

Geographic range: Fire worms live in all tropical seas.

Habitat: Fire worms live in crevices under and between rocks or in dead coral. They are also found in sand and mud.

Diet: Fire worms are omnivorous and will scavenge both dead plants and animals. They use their mouthparts to scrape and squeeze bits of food into their mouths. Prey is located by touch and also by special sensors that detect chemicals produced by other animals.

Fire worms have venomous bristles that cause swelling and burning if touched. (Photograph by Leslie Newman and Andrew Flowers. Reproduced by permission.)

Behavior and reproduction: Males and females are not always required for reproduction. Some individuals may break up into one or more parts, with each part growing into a new individual.

Fire worms and people: Fire worms get their name because of their stings that cause burning and swelling.

Conservation status: Fire worms are not considered endangered or threatened. ∎