Common name: Giant Acorn Barnacle
Scientific name: Balanus Nubilus

Kingdom: Animalia
Phylum: Arthropoda
Class: maxillopoda
Order: sessilia
Family: Balanidae
Genus: Balanus
Species: B. nubilus


Balanus nubilus aka, Giant Acorn Barnacle, are the worlds biggest barnacles. They are very common near pears. Also, these hard-shelled animals mostly live on rocks.

Balanus Nubilus is huge in size for a barnacle. It has a width of 5.9 inches, and a height of 12 inches. They range from bright to dark colors. They contain the largest known muscle fibers. They look different from others of there kind and are easily spotted with there bright colors.

This barnacle can be found in places like this, Alaska, and California. Mostly found on rocks, tropical waters, and legs of piers. found mostly at depths of 90 meters. There are many in the population. Balanus Nubilus is a thriving creature.

Balanus Nubilus eats plankton, and filter feeds. They eat plankton by, sticking out there feather like legs and sweep the near water for them. They are prey for sea otters, who eat them often. There abandoned shells are used by other organisms. One way they protect themselves from not getting eaten is their hard shells.

This giant barnacle is an important food source for many other species like sea otters. A fun fact is they live in groups. And they have both female and male parts.


Author: Madison M.
Date published: 4/13

Sources:, Race Rocks .com, Monterey Bay Aquarium .com
Picture credit:,%201854,%202.jpg