The Red Apple Crab – All You Need To Know in One Article!




Red Apple Crab

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The Red Apple crab is a generally unknown crab in the aquarium world. The Red Apple crab isn’t completely aquatic but is terrestrial. If you’re planning a paludarium, these crabs are a great choice.

These crabs are easy to care for which even makes them great for a beginner. They’re also fairly small and hardy.

Read on to find out more about how to care for this crab species.

Overview of The Red Apple Crab

Red Apple Crab Info
NameRed Apple Crab
Other NameChameleon crab
Scientific NameMetasesarma aubryi
Minimum Tank Size5 gallons
BreedingVery Difficult
Body Size1 – 1.6 inches
Leg Span Size3 – 4 inches
Water Temperature71 – 79 °F
Water typeFreshwater
Moisture70% and up
Lifespan6 years

Natural Habitat of The Red Apple Crab

The Red Apple crab originates from Indonesia. They live in areas near rivers and streams in dense forests. They prefer heavily wooded areas close to water.


Red Apple crabs are very small crabs. The average shell width is 1 to 1.6 inches, and their legs reach around 3 to 4 inches.

Despite their name, their carapace color can be red or dark blue, or purple lined with orange. They can also have a horizontal yellow line on both sides between the eyes. They have round red claws, brown legs, and yellow or green eyes.

They have red round claws, yellow to green eyes, and brown legs. They are also called Chameleon crabs due to their ability to display different colors depending on their surroundings.


In captivity, they can live 3 to 4 years although some have lived up to 5 or 6 years if the proper care is given. There isn’t much data about their lifespan in the wild.


Red Apple crabs are nocturnal, meaning they will often hide during the daytime. Although they are slightly aggressive, they are still fairly social. The larger the colony of crabs, the safer they will feel in a tank setup. These terrestrial crabs are territorial, however.

It’s best not to keep them with another crab species. They are larger and more aggressive than Vampire crabs, Tangerine-Head crabs, and Marble crabs so it’s best not to keep these species together.

Red Apple crabs enjoy digging in the substrate and making small dens.


In nature, Red Apple crabs are scavengers. They eat vegetables, roots, stems, dead insects, worms, larvae, and tadpoles. They are omnivores.

In captivity, Red Apple crabs need a mix of meat and veggies with a protein content that makes up 20 to 30 percent of their diet.

Foods To Feed Your Red Apple Crab

  • Vegetables such as lettuce, spinach, broccoli, peas, corn, or carrots
  • Fruits like sweet apples, mango, melon, bananas, etc.
  • Leaves like Oak or Almond leaves
  • Shrimp pellets
  • Brine shrimp
  • Algae wafers
  • Bloodworms
  • Detritus worms

How Often Should Their Food Be Changed?

It’s best to leave their food for a day but leaves can be left for several days. Remove spoiled food immediately.

Do Red Apple Crabs Need Calcium in Their Diet?

Red Apple Crab

For any crustacean, calcium is a key component that makes up the exoskeleton that is key to having a healthy crab.

Calcium can be given to your crab from foods like figs, seaweed, insects, eggshells, broccoli, spinach, kale, etc. Supplement their diet with these foods to make sure they are getting enough calcium.

Housing The Red Apple Crab

The Red Apple crab is simple to care for and housing them is also fairly simple. Follow these tips for a happy, healthy crab.

Tank Size

The minimum recommended size for a few crabs is a 5-gallon tank. They need their own tank space to move around and hide. Overcrowding can lead to stress for crabs which can cause health problems or aggressive behavior.

For a larger colony of these terrestrial crabs, add 1 or 2 gallons per additional crab.

Tank Lid

A tank lid is definitely necessary for these crabs. Red Apple crabs are very adept at escaping and will climb out of your tank if given the opportunity.


When choosing a substrate, it’s best to mimic the land crab’s natural habitat. The substrate should be moistened as if you were making a sandcastle. The substrate can be made from earth, sand, or a mixture of the two. Coconut fiber is also a great substrate option.

How Deep Should the Substrate Be?

It’s best for the substrate to be about 4 inches deep so that the crabs can burrow into it.

Land-to-Water Ratio

Red Apple crabs are terrestrial crabs, so they need at least 90 percent of the land area in a tank.

Water Bowl

Red Apple crabs can’t survive in freshwater for long, but they do need a shallow water bowl that is big enough for them to be able to completely sit in. It’s also best to have other surfaces like rocks around the bowl of water to ease getting in and out.

They only need fresh water. Chlorine and Fluoride are toxic to crabs, so make sure to get water that is free of these ingredients.

If you can’t find the type of water without these ingredients, you can also use a water conditioner or bottled spring water.


These freshwater land crabs prefer a warm, humid, tank with a temperature between 71 and 79 degrees Fahrenheit. They are poikilothermic meaning their body temperature is based on the surrounding environment, so it’s important to keep the tank warm because they can’t handle drops in temperature.

Using a heating pad or tank heater that covers a third of the tank can give these terrestrial crabs places to move around the tank from cooler to warmer when needed.


This species of land crab also prefers humidity. The level of humidity should be kept at 70-85% humidity for the adult crabs to properly breathe and molt. Use a humidity gauge to check the humidity often.

How Do I Keep the Humidity Up in the Tank?

There are a few different ways to keep the humidity level where it should be. Follow these tips:

  • Keep the substrate moist
  • Spray the tank space with chlorine and fluoride-free water twice per week
  • Put a bowl of water in the tank with dechlorinated water

If your humidity level is too low, simply add moisture or less ventilation. If your level of humidity is too high, you can add more ventilation. An excess of humidity can cause the substrate to mold. Getting the right humidity level can take some fine-tuning.


These crabs are nocturnal, so they need light to mimic these conditions, therefore bright light isn’t necessary.


Giving your adult crabs spaces to hide can prevent stress. Stress for crabs can be deadly just like aquarium fish. They also need hiding spots for molting.

Decorations like stones, bark, driftwood, rocks, crab huts, plants, etc. are all great additions to your aquarium. Crabs also love climbing, so decorations like fish nets can also add to the environment.


Plants are also beneficial for a healthy crab. Live plants can provide a place to shed bacteria from the crab’s shell and skin.

Molting Cycle

The molting cycle is key to the growth of your crab. The molting cycle sheds the current exoskeleton and grows a new one. It occurs in four phases:

  1. Pre-Molt
  2. Molt
  3. Post Molt
  4. Inter-Molt

In the pre-molt stage, the crab stops eating and becomes lethargic. To molt they need moisture, darkness, and heat. The molting stage is the removal of the old shell, which can last from 10 to 30 minutes.

The post-molt stage is the most vulnerable stage where they will hide until their new carapace has hardened. The inter-molting stage is the resting stage between molting cycles.

There are a few other factors to keep in mind during molting, including:

  • Don’t disturb them when they are molting or about to molt. If they disappear for some time, this is normal.
  • Keep providing ample food
  • Keep providing calcium-rich foods
  • Don’t remove the old exoskeleton from the tank space. The crab will eat this later. It has minerals that your crab needs to thrive.

How To Handle and Care for Your Crab

There are a few key things to keep in mind when handling and caring for your crab, these include:

  • Never lift them by their legs or claws because they can lose the limb
  • Remove uneaten food within 24 hours to prevent bacteria buildup

Males Vs Females

These crabs are sexually dimorphic so telling them apart can be a little difficult but there are a few dead giveaways.

Males are generally bigger than female crabs with larger claws. The male’s abdomen has a narrower shape with a slim plate and females have a broad plate on the belly. The base color of the male is also brighter than the female. However, it is important to note that after molting the colors can appear brighter.


Breeding these crabs in captivity is nearly impossible. A successful breeding attempt has never been recorded in captivity.

In the wild, these crabs move to the ocean to release their eggs, then they metamorphose and crawl back to land. Their breeding season is also variable, usually between May and November.

Suitable Tank Mates

If you’d like to keep a group of these crabs, it’s best to maintain a ratio of males to females from 1 to 3. If the tank size is too small, males will be very likely to fight. You should have a tank that is big enough to provide multiple hiding places.

If you plan on having a paludarium, you can keep fish or dwarf shrimp in the tank.

It’s best not to house them with other crab species like Vampire Crabs, or any type of crayfish.

Common Illness

All crustaceans can contract shell rot. Shell rot occurs when high doses of ammonia start to eat away the shell.

This can be prevented by giving a diet of calcium-rich food and using a type of water free from ammonia. If the disease is treated properly, it should be taken care of through the next molting cycle.


The Red Apple crab can be an awesome, unique pet to keep. As long as you follow our tips, these crabs are easy to care for and intriguing to watch.

As long as you keep the humidity level up, and provide a high-quality diet, a water bowl, and proper substrate, you’ll have a healthy crab.

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