Hermit Crab

Category: Sea Life

Popular as family pets, hermit crabs are found in family aquariums, tide pools, and oceans around the world.

Hermit Crab

Hermit Crab

Scientific & Common Names

These critters are usually just called hermit crabs because when they are disturbed they withdraw into their shells, barricading the entrance with their front claws. All hermit crabs are from the family Paguroidea, but there are over 500 species of hermit crabs in the world.


Even though a hermit crab resembles a crab and is called a crab, it really isn't a true crab. They are closer to lobsters than crabs. Hermit crabs have soft coiled bodies with no external protection. Because they have such soft bodies, hermit crabs use the discarded shells of other sea creatures as their homes. Hermit crabs can be from one-half inch long to four inches long, and they weigh between 7 and 18 ounces. Hermit crabs have eyes perched atop long slender stalks, four short antennae, and six visible legs.


Usually, hermit crabs reproduce in January or February. However, in the deeper parts of the ocean where the water temperature is less variable, hermit crabs may reproduce all year. After mating, the female hermit crab carries large masses of eggs attached to her body. After about 8 weeks, the eggs hatch. The tiny hermit crabs stay with their mothers for a few weeks before becoming independent. Hermit crabs are sexually mature around the age of one year.


Hermit crabs are omnivores that eat almost anything. Typically, a hermit crab will make a meal of worms, small fish, and plankton found in the water. Because hermit crabs are so small, they are prey to many other sea creatures. Octopuses, cuttlefish, squid, sharks, and fish may all eat hermit crabs. Therefore, hermit crabs typically hide around other sea creatures such as anemones. When a hermit crab grows, it moults. Eventually, the crab will outgrow its shell and have to discard it, seeking out a new home.


Hermit crabs play important roles in the ocean. They inhabit the bottom of the sea, cleaning up dead animals, and recycling organic matter. They are also filter feeders, straining algae and other microscopic creatures from the water.

Present status

There are over 500 species of hermit crabs, and they are distributed in oceans all across the globe. These interesting crustaceans are commonly found in tide pools and shallow waters, but they may also be found in deeper waters scuttling around on the ocean floor searching for food.


  1. http://www.edc.uri.edu/restoration/html/gallery/invert/hermit.htm

  2. http://a-z-animals.com/animals/hermit-crab/

  3. http://www.waza.org/en/zoo/choose-a-species/invertebrates/other-aquatic-invertebrates/pagurus-bernhardus

  4. http://www.montereybayaquarium.org/animal-guide/invertebrates/hermit-crab