Tube This hard cylinder, which varies in thickness between and even within species of tubeworm, is basically like the shell of a lobster or crab. (Scientists call it a "chitin proteoglycan/protein complex.") It grows as the worm grows, providing a safe home for the animal. The delicate plume, which is the tubeworm's only exposed part, can be retracted into the tube at a moment's notice, such as when a hungry fish happens by, hoping to nibble the plume. (back to illustration) Living at Extremes | Inside a Tubeworm | Deep-Sea Bestiary The Mission | Life in the Abyss | The Last Frontier | Dispatches E-mail | Resources | Table of Contents | Abyss Home Editor's Picks | Previous Sites | Join Us/E-mail | TV/Web Schedule About NOVA | Teachers | Site Map | Shop | Jobs | Search | To print PBS Online | NOVA Online | WGBH © | Updated October 2000