Definition
Aplacophora is a group of small, worm-like mollusks that lack shells. They are marine organisms found in various depths of the ocean. Aplacophorans are often covered in calcareous scales or spicules. They move along the seafloor, feeding on microorganisms or small invertebrates. The term Aplacophora literally means "without shell." They are closely related to chitons and other mollusks.