Tusk Shells: Scaphopoda

The tubelike shells of scaphopods (SKAF-oh-pods) measure up to 7.8 inches (200 millimeters) in length. They are long, tusk-shaped, and open at both ends. The broadest end of the shell is considered the front. A muscular foot and slender feeding tentacles reach out from the front opening. The mouthparts are made up of a radula (RAE-jeh-leh) that is short, thick, and has five extremely hard teeth. The opening at the narrow end, or at the rear of the shell, is where oxygen-carrying water flows in and waste, eggs, or sperm flow out. The shell is usually white, but in some species the shells are green or have red or yellow bands. The shells of other species are clear, and the internal reproductive organs are sometimes clearly visible.