The New Quirky Pet: The Halloween Moon Crab

The New Quirky Pet: The Halloween Moon Crab
Getty Images
Getty Images

Have you ever seen a Halloween Moon Crab? They have the most incredible appearance of any crabs in the world, with their wild colors and adorable faces.

The most remarkable thing about these curious, clacking creatures is that they thrive in captivity and, as a result, make fantastic pets! Let me acquaint you with the wondrous world of Halloween Moon Crabs. In this article, we will give you some tips on how to give these pets a wonderful life.

A Halloween Moon Crab As a Pet, Really?

Halloween Moon Crabs (also known as the Halloween Hermit Crab) are gaining notoriety for their remarkable ability to tolerate captivity exceptionally well. In the company of crabs of the same species, they appear to enjoy a longer and healthier life. If you intend to keep a Halloween Moon Crab as a pet, you might as well acquire a pair.

Keep in mind that they enjoy fighting, sometimes to the point of death, so the best course of action would be to place them in separate tanks and allow them to play together while under surveillance.

This will allow you to admire their beautiful blackish carapace with brilliant jack-o’-lantern orange legs and their “dangerous-appearing” purple claws, which they raise into a sparring position if any uninvited fingers approach: in fact, they appear to be begging for a hug.

What about Halloween crab care?

Now let’s examine how to care for a healthy Halloween Moon Crab, which, despite their apparent docility, requires constant attention.

Some pet store employees will tell you that crabs don’t require any special food, heat, or substrate other than newspaper, water, and table scraps, but don’t listen to them: they’re here to sell. Halloween Moon Crabs require special attention and care. You will discover, however, that they are so adorable that it may be difficult to allow them to sleep quietly.


When adopting one of these magnificent creatures, keep in mind that they have a relatively long lifespan: 8 to 10 years! Prepare yourself for a long-term pet companionship. Take care of the care sheet for your Halloween moon crab in order to provide it with a better life.

Reproducing the Halloween crab habitat

Halloween Moon Crabs are land crabs native to the Pacific coast; they are typically found from Mexico to Panama in mangroves, sand dunes, and rain forests, but must return to the ocean to breed.

In order to reproduce in their tropical habitat, they require a constant supply of water, as well as the proper temperature and lighting. They are nocturnal, so if you never see them moving during the day, they are not dead; they are simply sleeping. They also enjoy climbing and digging; in their natural habitat, they can dig as deep as 4 feet to create a network of underground burrows where they can shelter, mate, and molt.

Choosing An Appropriate Tank Size

Minimum enclosure size for a single crab is a 15- to 20-gallon aquarium (count at least 30 gallons for a pair). Even though they are not the largest crabs, they can still grow between 2 and 2.5 inches (5 and 6.5 centimeters) in length and require space to be happy.

The environment you provide for them must be able to sustain them in both time and space, especially if you intend to acquire a pair as suggested. Remember that your Halloween crab tank size must be adequate for him, and do not listen to the pet store employee who will recommend a 10-gallon tank.

Providing a Proper Substrate

Now, we will discuss the setup for the Halloween crab tank. Approximately 4 to 6 inches (10 to 15 cm) of sand and an additional 3 to 6 inches (8 to 15 cm) of moist peat moss is the optimal substrate for your crabs’ tank.

Again, some may argue that using standard newspaper as a substrate is sufficient. Wrong! This is inadmissible. As previously stated, crabs enjoy digging: to molt, they require sufficient space to burrow deeply into a moist (but not wet) substrate. They can also undergo a brumation phase in which they hibernate underground (see “About Molting and Brumation” below).

Because of this, you must choose a substrate that will allow them to dig freely, such as fine sand or loose soil.

Crabs Love Climbing

As previously stated, crabs enjoy climbing, so you must provide them with places to do so, such as rocks, rough wood or branches, plastic plants or foliage, and, even better, cork bark, which is readily available at pet stores.

Cork bark is practical because it is inexpensive, lightweight, and durable. It is also recommended because it is known to retain water very efficiently, which helps maintain the humid environment crabs require (see below, “They require constant moisture”).

It also serves as a shelter, which is never in short supply for nocturnal creatures that must hide during the day. Additionally, coconut shells can be used as aboveground housing.

They Need Constant Moisture

You must always provide freshwater and saltwater in separate pools: one for drinking and the other to keep their grills moist, which is essential. The pools must be wide enough for crabs to climb in and out of, but also shallow, as crabs cannot swim and therefore can easily drown!

Add small rocks or shells to the bottom of the pools to aid crabs in entering and exiting safely. Ensure that you change the water daily so that it does not run dry, remains clean, and prevents the growth of bacteria (crabs are very sensitive to it). To avoid the chemicals added to tap water, the best option is to use filtered or spring water.

In addition, they require a constant humidity level (around 70%). It is generally recommended to obtain a psychometer or other device for measuring humidity and to spray the aquarium regularly in order to maintain the ideal level.

Lightning and Heat

The optimal temperature to keep Moon Crabs alive and healthy is between 26 and 27 degrees Celsius (80 and 85 degrees Fahrenheit). The temperature must never fall below 25°C (75°F) or rise above 30°C (85°F).

A low-wattage light bulb is ideal for crabs because it helps maintain a high level of humidity while keeping the terrarium darker. Less light will make the crab feel more secure while still providing sufficient light for visibility and heat for evaporation.

What do moon crabs eat?

If you recently purchased a Halloween crab, you may be wondering what captive sea crabs eat. Moon Crabs are predominantly herbivorous, consuming primarily leaf litter and young plants.

You can also feed them exotic fruits such as mangoes, papayas, and coconuts, as these are the types of fruits they would encounter in their natural habitat. Vegetables are also sufficient because they contain the necessary nutrients. Meat is acceptable so long as it is thoroughly cooked; otherwise, your crab may develop health problems.

Regarding quantities, keep in mind that crabs do not consume food when they are not hungry. On the other hand, they can perish rapidly from malnutrition.

Therefore, it is best to provide extra food and remove leftovers the following day (always clean the dish properly before adding more food; again, crabs are very sensitive to bacteria and mould).

Also, remember to give them saltwater, as it provides the salt they need in their natural diet, and to give them a lot of calcium after they molt (see below).

About Molting and Brumation

Molting is the annual process by which a crab sheds a layer of its exoskeleton and replaces it with a new one (depending on the crab and its environment, it may be twice a year or once every two years).

It may take several days to accomplish. When the crab’s colors become drab and white appears around its eyes, it is about to molt. In their natural environment, crabs would molt underground; therefore, it is recommended that darkness be maintained during the process and that no attempts be made to observe or disturb the crab if it is hiding.

After the procedure, the crab’s shell will be extremely fragile for a few days; therefore, you should handle it with extreme caution.

Upon completion of the procedure, your crab will require a new skin. For this, it will require a great deal of calcium and other nutrients, which it will obtain by… consuming its old skin! Ensure that it remains in the tank. Only if it has not been consumed within two days may it be removed from the container.

Additionally, you can grind up the remainder of the exoskeleton and add it to the next meal for a complete, healthy diet; this will help him strengthen his new carapace. Food supplements are also available in exotic pet stores.

Regarding brumation, note that it is not a normally occurring process in crabs. They can enter a phase of dormancy, but it is not the same as hibernation.

It frequently results from an insufficient environment (to cold for example). Just be aware that if he is not moving, he may not be dead, but you should likely reevaluate how you are caring for him.

Give Your Moon Crab Lots of Love!

Know that, similar to humans, crabs vary in their attitudes and behaviors. Some will enjoy being handled, while others will not. If yours is constantly pinching or hiding, you should spend time with him every day to help him adjust to human interaction.

After some time, you may be able to change its “crabby” disposition into a more human-friendly one, and who knows, he may become extremely attention-seeking and not at all sky-oriented, like other Moon Crabs. The best piece of advice is to study your crab’s behavior and respond accordingly.