What Are the Suction Cups on an Octopus Called?

By Vivian Crosswhite; Updated April 24, 2017
Octopuses have arms lined with suction cups.

An octopus is a cephalopod. Cephalopods are the largest of mollusks. They are extremely fast and intelligent. Their eyes are very good at focusing in on prey. All cephalopods have either arms or tentacles. Octopuses have arms that are lined with suction cups for gripping and moving around. These suction cups are also commonly referred to as suckers.

Suckers

Suckers are made up of special muscles.

Octopuses use their suckers to latch onto objects, the same way a suction cup does. These suckers can also move the objects around because they are made of special muscles.

Outer Infun­dibu­lum

The outer infun­dibu­lum is the muscle that controls the rim of the sucker. It changes shape so that it can create a seal around an object.

Inner Acetabulum

The inner acetabulum muscle forms the wall of the sucker. It contracts, causing negative pressure to build up. This creates the suction. The amount of grip a sucker has depends on how many of these muscles are flexed. More flexed muscles mean a tighter grip.

Extrinsic Muscles

The extrinsic muscles allow the rim of the sucker to spin an object in a complete circle. This can be done at any angle to the arm without losing suction.

About the Author

Based in Atlanta, Vivian Crosswhite has been writing for over 15 years, with work appearing on various websites. Crosswhite has been a writing coach for high-school students in the Atlanta area. She holds a Bachelor of Arts in creative writing.