The term 'Marine Worm' encompasses four different species of invertebrates. TEREDO is a genus of saltwater clams, also known as shipworms, that bore into wood and can cause extensive damage to wooden structures in the ocean. Sipunculid is a type of marine worm that lives in burrows in the sand or mud and has a retractable proboscis. Seamouse is a type of bristleworm that lives in the intertidal zone and has a segmented body with bristles. Nemertean is a type of ribbon worm that lives in the ocean and has a slimy, mucous-covered body. All four species are important components of the marine ecosystem.