Lancelets are small fish like creatures that live in the sandy bottom of shallow tropical oceans. unlike tunicates, adult lancelets have a definate head. They have a mouth that opens into a long pharyngeal region with up to a hundred pairs of gill slits. Lancelets feed by passing water through their pharynx, where food particles are caught in a sticky mucus. This music is swallowed into a digestive tract that starts at one end of the pharynx and continues straight through the animal to the anus. They have a simple, primative heart that pumps blood through vessels in a closed circulatory system. Unlike most vertibrates, lancelets have no jaw. Their mouth is composed of soft tissues. Lancelets also lack appendages and can move only by bending their bodies back and forth.
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