Hermit crabs are cute, sociable creatures that tend to be more active after the sun goes down. Though they seem to require little maintenance, their habitat requirements are stringent and they require lots of care.
Discover the details of how to take care of a hermit crab with regards to its diet, housing, grooming and socialising needs and read about the common health problems owners should look out for below!
*Disclaimer: The content in this article provides general information that should not be used as a substitute for professional advice from a vet. Please consult a vet for their advice on how to take care of your hermit crab.
Types of Hermit Crabs
These are the key traits of land hermit crabs in general:
|Size||2 - 6 inches / 5 - 15cm|
|Life expectancy||10 - 20 years|
1. Ruggie (Coenobita Rugosus)
Appearance: Black, white, gray, tan, blue or peach bodies, elongated eyes, sandy-colored eyestalks and striations (stitch marks) on their large pincer
Ruggies are the only species of land hermit crabs allowed for sale in Singapore, according to the Animal & Veterinary Service (AVS)!
They typically have a lifespan of 10 years or more and are commonly found along the coastlines. As land hermit crabs, Ruggies live on dry ground but require access to both land and water.
Though their elongated eyes make them look similar to Ecuadorian crabs, their sandy-colored eyestalks, large pincers with striations and orange feelers serve as their distinctive features.
2. Purple pincher (Coenobita Clypeatus)
Appearance: Brown/dark purple legs with a tinge of orange/red, round eyes and large dark purple claws
The purple pincher crab, otherwise known as the Caribbean crab, can be identified by its round eyes and large claws. Its legs are brown or dark purple with a tinge of orange or red.
This species of hermit crab tends to prefer shells with a round opening (turbo shells).
3. Ecuadorian crab (Coenobita Compressus)
Appearance: Gray, orange or yellow bodies, elongated eyes
The Ecuadorian crab can come in a range of colors including yellow, orange or gray and their bodies may occasionally have a bluish tint. Additionally, their claws are the same color and shade as their legs.
Unlike the purple pincher crab which has round eyes, the Ecuadorian crab has elongated ones. They also tend to be more active than their purple pincher counterparts.
4. Strawberry hermit crab (Coenobita Perlatus)
Appearance: Bright, red bodies and orange feelers
The name of this species, strawberry hermit crab, is derived from the distinctive bright red color of their bodies. If you notice your strawberry hermit crabs having a washed-out colour, it could be a sign that their diet is lacking in carotene.
To match their overall look, strawberry hermit crabs also have orange feelers!
5. Indonesian crab (Coenobita Brevimanus)
Appearance: Brown or purple bodies, large claws and thin, dark-colored eyestalks
Despite their name, the Indonesian crabs don’t only originate from Indonesia but also the southwest Pacific Ocean and east coast of Africa.
This species has brown or purple-colored bodies and large claws that don’t match their small size. They can also be identified by their thin, dark-colored eyestalks.
How to Take Care of a Hermit Crab
Aquarium size: 24″ x 12″ x 12″ / 61cm x 30.5cm x 30.5cm per hermit crab
Aquarium material: Glass
Temperature: 71.6 – 82.4°F / 22 – 28°C
Humidity: 60 – 80%
The 3 most common types of substrate used in a hermit crab’s habitat are:
• Play sand
• Coconut fiber
• A mixture of play sand and coconut fiber
You’re advised to fill the aquarium with a sizable amount of substrate, typically 5cm deep or twice the height of the shell of your largest crab, in order to provide sufficient room for the crabs to burrow during the molting process.
Additionally, the substrate should be kept slightly moist to provide some humidity to their habitat.
Maintaining the right level of humidity within the aquarium will aid in your hermit crabs’ breathing. To achieve this, both heat and water are required.
Incandescent lights or under-tank heaters can be used to provide the right amount of heat in the aquarium while a slightly moist substrate and mist of non-chlorinated water help to provide the moisture needed for a humid environment.
Covering the tank with a lid will also help to regulate the temperature and humidity in the aquarium.
If you’re living in a humid country like Singapore, additional amenities used for regulating humidity like under-tank heaters and incandescent lights aren’t required as the atmospheric humidity is sufficient to meet these crabs’ needs!
Lighting in the aquarium is also important for hermit crabs as they regulate their behaviours such as feeding time based on light.
LED or fluorescent lights can be used and they should be kept on for 8 to 12 hours daily to mimic natural light cycles.
Furnishings and decorations
Metallic substances are toxic to hermit crabs. Hence, all food and water dishes should be made of ceramic, plastic or other non-metallic materials.
You’ll need 3 dishes in total:
- For food
- For non-chlorinated freshwater
- For non-chlorinated saltwater
To neutralise the chlorine in tap water, simply mix some water conditioner with tap water. The amount of water conditioner to use will depend on the product you’re using so it’s important to refer to the label for the instructions.
This is also applicable to homemade saltwater, which uses non-chlorinated tap water and marine salt!
You can create a safe space in the aquarium where your hermit crabs can hide with the help of sea sponges or artificial plants. Ornaments such as rocks can also be included to offer your crabs an avenue for climbing.
Finally, do leave an empty space in the aquarium as well so your hermit crabs can exercise freely!
Your water bowl shouldn’t be too deep such that your hermit crabs are unable to climb out of it (they can drown!).
Place a sponge in the bowl to aid them in climbing out safely or get a bowl with a ramp so your crabs can climb out on their own with ease.
Habitat care and maintenance
Maintaining the cleanliness of your hermit crabs’ habitat is relatively simple. These are some general guidelines:
- Remove food and replace with a new batch daily to avoid mold growth
- Clean their water bowls at least twice a week and whenever it’s dirty
- Deep clean the tank every 2 – 4 months (includes changing of the substrate)
- Spot clean to remove waste whenever necessary
You should also check the substrate and ensure that it remains slightly moist. If it’s dry, simply spray some freshwater (non-chlorinated) or non-chlorinated water.
Hermit crabs are creatures capable of cleaning themselves provided that they have both freshwater and saltwater that are non-chlorinated readily available. Just place a bowl that’s deep enough for them to submerge their bodies in the aquarium so they can clean themselves whenever they wish to.
If the bowl doesn’t have a ramp where your hermit crabs can climb out easily, place a sponge in the bowl so they have help getting out.
As hermit crabs are social creatures, they should be kept in groups of 2 or more. This will prevent them from getting lonely.
Additionally, you can take your crabs out of the aquarium to play so they don’t get bored!
An issue that could occur when keeping more than 1 hermit crab in an aquarium is fighting.
Fighting may occur if there isn’t enough food or water. Additionally, if there are insufficient shells in the tank, some crabs may get aggressive and steal shells from others. Thus, it’s critical to provide spare shells that are slightly larger than their current ones as well as sufficient climbing ornaments in the aquarium.
As you add more crabs to your aquarium, you may need to upsize the tank so that each crab has his own space!
Hermit Crab Molting
Frequency: Twice a year
Hermit crabs go through a process of molting, where they shed their old skins and allow their new ones to harden. The hardening process will take a couple of weeks.
During this time, they may become less active and even burrow into the substrate. They may also drink water excessively and avoid eating.
If you notice your hermit crab eating his old skin, don’t be alarmed! This is normal behaviour and the skin serves as a great source of calcium for your crab.
Due to their inactivity, it can be difficult to tell whether your hermit crabs are dead or molting. However, it’s important that hermit crabs don’t get disturbed during their molting process.
Therefore, the safest option is to assume that your crabs are molting. If they’re no longer alive, you’ll be able to identify a rotting smell in a couple of days. Otherwise, they’re simply molting!
After molting, your hermit crab will usually change the shell he lives in. Thus, you should provide at least 3 to 5 empty shells per crab that are larger than the previous one in case your crab has grown.
The increase in the size of the shells should be gradual and they shouldn’t be cracked or have holes in them!
Diet of a Hermit Crab
Feeding frequency: Once a day
Wild hermit crabs tend to feed at night. Thus, your pet crabs should also be fed at night.
Their ideal diet should consist of:
- Crushed pellet food
- Fruits such as apple, grapes and banana (as supplements)
- Leafy vegetables such as kale or broccoli (as supplements)
- Freshwater (free of chlorine)
Their diet can also include things like cooked eggs, meats, seafood (in moderation), freeze-dried shrimp, plankton, brine shrimp and fish food flakes.
Common Health Problems Found in a Hermit Crab
Note: The symptoms listed below are non-exhaustive and non-specific.
Symptoms: Inactive, lethargic, aggressive, refusing to consume food or water, tendency to hide or leave their shells
Hermit crabs can get stressed due to a variety of reasons including overcrowding, loneliness and bullying. Getting dropped on their shells or being exposed to temperatures that are too low or too high can also cause them to feel stressed.
When they’re stressed, they become inactive and lethargic and you may notice them leaving their shells. Thus, providing them with sufficient space in the aquarium and handling them with care is important.
It’s unusual for hermit crabs to leave their shell and walk around without them as they risk being exposed to attacks from other crabs. If you notice this behaviour or any other signs of stress in your crab (without any immediate underlying cause), you’re advised to consult a vet immediately!
Symptoms: Inability to hold their shell up, dropping their shell, sitting in water, pulling off their limbs
Hermit crabs are sensitive creatures. They can easily get poisoned from chlorine found in water and any chemicals found in household detergents and cleaning sprays. Hence, only filtered water should be used to clean your crab’s aquarium.
If your hermit crab is suffering from poisoning, he may not have the strength to hold his shell up and may end up dropping it. You may also notice him sitting in water or pulling off his limbs.
As hermit crabs are unable to wash off the toxins on their own, they may try to detach the affected areas like their limbs from the rest of their body.
Frequently Asked Questions
Will hermit crabs pinch?
Hermit crabs can be held and will only pinch when they feel scared or threatened. Avoid forcing them out of their shells and handle them with care as they can get hurt or stressed if dropped on their shells!
Is it easy to take care of a hermit crab?
No! While hermit crabs are often believed to be low maintenance pets, they have very strict habitat and care requirements. Thus, they aren’t ideal pets for first-time owners.
What equipment do I need for a hermit crab habitat?
These are the basic equipment and items you’ll need for a hermit crab habitat:
- A tank (24″ x 12″ x 12″ / 61cm x 30.5cm x 30.5cm per crab)
- A substrate (at least 5cm in depth)
- Spare shells
- Climbing ornaments like rocks
- Sea sponges or fake plants to create a hiding spot
- Non-metallic bowl for food
- Non-metallic bowl for non-chlorinated freshwater
- Non-metallic bowl for non-chlorinated saltwater
- LED or fluorescent lights
- Water conditioner to remove chlorine from tap water
- Marine salt
How often should I feed my hermit crab?
You only need to feed your hermit crab once a day. To prevent mold from growing, clear out any leftover food and replace it with new ones the next day!
Caring for a Hermit Crab
Hermit crabs are adorable creatures with their own unique set of characteristics. Given their stringent care requirements, learning how to take care of them properly will ensure that your hermit crab stays happy and healthy and lives his life to the fullest!
If you’re unable to care for your hermit crab, don’t release them into the wild. Instead, give them to a friend, return them to the pet shop where you purchased them or give them up for adoption.