Practice question

Nemertea comprise elongate unsegmented soft-bodied highly contractile predatory worms known as ribbon worms due to extremely long flattened ribbon-like body capable of enormous extension, some species like Lineus longissimus reaching over 30 meters longest animal known, often brightly colored. Dorsoventrally flattened marine benthic predominantly few freshwater terrestrial forms. Characterized by unique eversible muscular proboscis housed in separate rhynchocoel cavity, complete tubular gut and closed circulatory system. Active hunters employing proboscis often armed with stylet to spear polychaete prey and crustaceans, hence also called proboscis worms reflecting hunting apparatus.