Nautilus is a marine creature that belongs to the cephalopod family. Here’s a description of a Nautilus diagram with points:

• Shell: Nautilus has an external hard shell that is spiral in shape. The shell is divided into several chambers.
• Mantle: It is a soft, muscular tissue that secretes the shell and is enclosed by it. The mantle can contract and expand to help the nautilus move.
• Tentacles: Nautilus has around 90 tentacles that are used for sensing, grasping prey, and locomotion.
• Eye: Nautilus has two large eyes that can detect light and movement. They are situated on the sides of the head.
• Siphuncle: It is a tube-like structure that runs through the chambers of the shell and helps in controlling buoyancy by adjusting the amount of gas in the chambers.
• Funnel: The funnel is a muscular tube that is used for propulsion by expelling water from the mantle cavity.
• Head: The head of a nautilus contains the eyes, tentacles, and beak, which is used to crush the prey.
• Mouth: Nautilus has a small beak-like mouth that is used to crush the prey before ingesting it.
• Anus: It is a small opening located near the funnel through which the waste material is expelled from the body.