Input (grade 11): Sipunculans are worm-like animals ranging from 2 t in length, with most species being under 10 c/O. The sipunculan body is divided into an unsegmented trunk and a narrower, retractable anterior section, called the "introvert".
Output (grade 8): Sipunculans are worm-like animals ranging from 2 t in length, with most species being under 10 c/O. The body consists of a narrow front section, called the introvert and a larger trunk section.