Hermit Crab Giant: Life Cycle, Habitat & Feeding

Hermit Crab Giant
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What do you know about Hermit Crab Giant? Is it as easy to raise as advertised? Check out the detailed article below to know more useful information about it.

Hermit Crab Giant: Life Cycle, Habitat & Feeding

In the Caribbean P. Diogenes, many people are pretty familiar with the Hermit crab giant. This is the largest crab species of hermit species discovered in the sea. 

They have a body up to 30cm with blue or green color and long red and white antennae that are unusual and eye-catching. Today, we will learn exciting information about the Hermit crab giant!


As shared above, this is a giant crab whose forks are of different sizes. Usually, the right side will be slightly larger than the left. The textures of tomorrow will overlap.

Several species of crabs that are thought to be hermaphroditic will persist in size with adults. According to research, males grow faster, more significantly than females.

The maximum length of the forks will be up to 40mm for males and about 32mm for females.

However, the Hermit crab giant is found when they live inside the shells of animals with large bellies, combined with sharp claws to increase their size significantly.

Males will not only grow larger in width but also weigh more than their counterparts. The average weight of the Hermit crab giant is about 95g for males and only about 50g for females.

Life Cycle

It is said that the Hermit crab giant uses its sharp claws to defend and attack in battles for territory or mates.

Hermit crab giants reproduce through the transfer of spermatogenesis from males to females. After undergoing fertilization, the female holds the eggs to her abdomen and begins developing for them.

After the eggs hatch and enter the aquatic environment, they will go through 5-6 stages of glaucophane before turning into an adult crab.

The total spawning time of the Hermit crab giant will be around 31 – 84 days, depending on the food source and the water temperature.

According to research, when carrying the baby, the female will have the abdomen expand about 10mm. Many people believe that this is the transition size from baby crabs to adult crabs.

Habitat and Activity

According to observations of scientists or ocean researchers, the Hermit crab giant can be found offshore, estuaries during their formation and development. As for the large animals, you can easily see them in the coral reefs. Sometimes this crab is also found in areas with shallow water or about 30m deep.

Hermit crab giant shells are used for many different functions and purposes. All these crabs depend on a shell to protect them from attack by other predators.

The claws and shells are the parts that help the Hermit crab giant to move quickly in any terrain. Their carapace can store water, allowing them to survive in arid regions.

In addition, the shell of the Hermit crab giant will also affect its reproduction and development. When the cover has fully developed, the crabs begin to think about finding a more significant “new home”, with enough capacity to help them survive and thrive.

Factors such as scent or water levels will also help them find a new home sooner. With the perfume element, they will identify “new home” through the shells of dead animals or calcium in the shells.

The Hermit crab giant does not kill snails to compete for new shells, they use a more civilized way of fighting to see who wins and that shell will go to the right person.

Once the Hermit crab giant has found a new shell, it will carefully examine the inside and outside by rolling over and using its claws to explore.

The process of “moving to a new home” is done relatively quickly, and it is at this time, the crabs are also easily endangered by other predators.

Food and Feeding

Hermit crab giant is considered “opportunistic” and intelligent when they hunt based on the carcasses of other invertebrates or scavenge, foraging in the macroalgae.

There are some of the shellfish that the Hermit crab giant loves, like the queen conch. The shells of this species are also beautiful to crabs.

Population Ecology

The population organization of the Hermit crab giant depends on factors such as sex ratio, morphological relationships, and reproductive period. In general, males are more numerous than females. It is also why the appearance of hermaphroditic species is becoming more and more popular due to enjoying more benefits than females. In addition, males can fertilize multiple females at once.

The size of the Hermit crab giant will depend on two main factors: season and life expectancy due to changes in weather conditions, mortality rates, migration, and food reserves within a year.

Hermit Crab Giant
Hermit crab giant – Source: Wikimedia

The density of this crab species is highest around June – August. It is the time when the temperature is quite suitable for reproduction and development.


According to the study, Hermit crab giant reproduction occurs sexually by mating from where sperm is transferred from the male to the female.

After successful fertilization, the eggs will be kept in the female’s womb to form and develop.

After a while, the number of eggs will start to grow to become what the crabs become.


Juvenile behaviour

To “transform” into an adult crab, they must shed their outer shell. This process is named molting or ecdysis.

This growth stage is relatively rapid, and they will quickly change the shell about 5-6 times in the first month.

When reaching adulthood, crabs will go looking for shells that are suitable for them.

Antipredator behavior

Strong claws are not only a weapon to help them find prey quickly, but also help them protect themselves from other enemies.

Hermit crab giant is relatively well protected when it has a strong shell. This crab also has an ability called autotomy.

It is a reflex action in response to trauma when a “leg” is nearly separated from the body. Hermit crab giants can easily automate and regenerate body parts.

The communication between crabs is generally divided into 2 main types: mating or fighting with enemies.

Hermit Crab Giant
Hermit crab giant – Photographer: Jasper Nance

Applied Ecology

In general, the Hermit crab giant does not have too many threats or hunting rules because it is considered a rather lovable animal.

This crab can be caught and kept as a pet, but the owner must create a space, a natural environment like the sea, to help them survive and develop.

Hermit Crab giant and Human Interaction

Humans have been exerting many direct and indirect effects on the existence of the Hermit Crab giant. The degraded and polluted living environment makes them face many dangers in finding their “new home”.

Pollution can make them confused and disoriented in their search for a replacement shell.

In addition, the human harvest of shells has caused them to struggle with each other to find a suitable home.


With Hermit Crab giant species that have been domesticated for many years and become pets, many people consider this crab species to be semi-domesticated because humans have bred them for a long time.

However, this hybrid Hermit Crab giant is selectively or will be bred for some purpose. In addition, a few species of Hermit Crab giants that usually live on land are also kept as pets.

Does the Hermit Crab giant Make a Good Pet?

Taking care of the Hermit Crab giant is not too difficult, but it must be cared for properly. The crabs can be captured and handled, but only to the extent allowed.

Therefore, quite a few people consider the Hermit Crab giant like a family pet. However, if your family has young children, you need to ensure adult supervision.

Hermit Crab Giant
Giant hermit crab (Petrochirus Diogenes) I caught off the coast of Belize – Source: Wikimedia


Suppose you are planning to keep the Hermit crab giant as your pet. It would help if you prepared a tank with a lid to live in a sea-like environment (as shared above).

You’ll need to give this crab about 2-3 inches of sand or a reptile-like substrate for it to dig and have plenty of places to hide, as it usually does.

In addition, you must make sure to provide more oversized covers so your pet can find “new homes” for themselves when needed.

You might consider feeding the Hermit crab giant commercial pellets and supplementing their diet with fruits and vegetables.

Beliefs, Superstitions, and Phobias About the Hermit Crab giant

Many people think that the Hermit Crab giant is just like a regular pet and nothing too special. They can be played, sightseeing in a few months can be exchanged.

However, this animal needs careful care and specific nutrition to live a long time. According to many reports, Hermit Crab giants will usually live for about ten years, and if you know how to take care and “love” them, they can live about 32 years.



Thus, today’s article has shared with you helpful information about the Hermit crab giant. Hopefully, the above sharing has helped to understand better and know a few more tips if you plan to “receive” them as pets!

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