Basic Needs
Crabitat: Aquariums or large critter keepers
Temperature: 76 - 80 degrees F.
Humidity: 76-80%
Substrate: Calci-Sand, Aragonite Sand, Moist coco-fiber bedding, Crushed coral, or a mix of any two.
Food dishes
2 Water dishes
Extra Shells
Climbing toys
Hygrometer to measure humidity
Thermometer to measure temperature
Water Conditioner
Instant Ocean Sea Salt for the dish of saltwater
Natural Sea Sponges
A Heat Source
Lighting
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More on Substrates
You want a substrate that is relatively easy to clean, attractive and holds up to hermit crabs' tunnelling activities. The best substrates are sand and coconut fiber. There are many benefits to using coconut fiber. It is one of the very best molting mediums out there. Coconut fiber will not collapse heavily upon a newly-molted crab and damage it, unlike sand. The substrate needs to be deep enough to allow the crabs to bury themselves.
Water
You will need to remove the chlorine and other harmful chemicals from the water before giving it to your crab. Repeated exposure to chlorine causes blisters to form on the crabs' gills, resulting in suffocation and death. You need to check the water dish daily, and make sure that it is clean and full of water. NEVER use anything metal as a water dish. Land hermit crabs are extremely sensitive to metal. Land Hermit Crabs must have both fresh and salt water for drinking.
Bathing
Hermit crabs need to be hermit crabs need to be bathed every week because in the wild hermit crabs are frequently rained on and live in a very humid environment. Bathing is absolutely necessary, it keeps their modified (stiffened) gills moist. Be sure to dechlorinate the bath water. The temperature of the water should be tepid, about the temperature of the surrounding room (not noticeably hot OR cold). Let him sit in the bottom of the bowl for about three minutes and then remove him. Bath time is an excellent time for you to clean and re-order the crabitat. Use a kitchen strainer or fish net to strain the sand to remove all crab poops, bits of exoskeleton and buried food. Shake the sand out of the empty shells and replace the food in the food dish. Put all their climbing toys back to where they were the week before, or arrange them differently for a new look.
Cage Accessories
Hermit crabs really enjoy climbing all over and hiding in almost anything you can give them. Some really good ones are:
# Dried choya (or cholla) wood (they actually like to eat it too)
# Sand-blasted grapevine
# Driftwood in any shape or form
# Plastic plants
# Coral, barnacles and sea fans (coral also provides additional calcium)
# Man-made 'hermie huts' for them to hide in
# Man-made 'half logs' also as hiding places
# Unpainted clay flower pots
# Plastic reptile ladders
# Plastic "hamster" ball
Be careful and don't put and resinous (evergreen) wood into the crabitat. Crabs are arthropods (in the same phylum as insects) and, just as cedar or pine irritates moths, it also annoys hermit crabs.
Sponges
Sponges aid in humidity. Water evaporates from the sponge and sponges if placed in the water dish, prevent a crab from drowning.
To Clean Sponges: thoroughly rinse in hot water and then soak in a sea salt solution, followed by a rinse in some dechlorinated water.
The Importance of Humidity
The the single most critical element of keeping land hermit crabs alive is keeping their environment humid. Land hermit crabs have modified, stiffened gills which allow them to breathe air. The air a hermit crab breathes has to be humid or the gills will dry out and the crab will endure a long unpleasant death of suffocation.
Tips on keeping the humidity level up
Check the hygrometer (humidity gauge) daily. You want to keep the humidity level between 70% and 80%. If you are keeping your crabs in a plastic critter keeper, use plastic wrap to cover the holes on the lid to trap humidity, or place a warm moist towel over the lid for an immediate humidity boost. If your crabs live in a glass aquarium, you can purchase a glass lid for it at most pet stores.
Diet
In the wild, land hermit crabs eat a wide variety of foods: fallen fruit, decaying wood, leaf litter, plants and grasses, and items washed ashore by the tide. They are not fussy eaters by nature and have even been observed even eating fecal matter. Hermit crabs locate food in two ways, by smelling it and by seeing other crabs eating. hermit crabs require calcium, carotene and antioxidants just like people do. A crab whose diet is carotene-deficient will fade in color after molting, from a nice reddish or orange color to a washed-out tan or gray. To make sure your crabs get adequate carotene, supplement their diet with brightly-colored vegetables, like corn and carrots. Also you can add ground dried organic marigold petals to your crabs' food. You should be absolutely certain that the marigolds were grown without pesticides before adding them to crab food. For example, the small plastic containers of marigolds that you fine at the local greenhouse are probably treated with pesticides and therefore unsuitable for crab food. Land hermit crabs are omnivorous and therefore eat just about anything. You can feed them meat, fish, vegetables and fruit (yes even citrus fruit!). Crabs also like tannin-rich foods, such as oak leaves and tree bark. Before giving your crabs these things as food, make sure they are thoroughly cleaned by washing in water (no soap) and allowed to dry -- crabs like their leaves crunchy.
Other foods crabs enjoy:
# Fruit, all kinds including mangoes, coconuts and papayas. Just be careful they don't get ahold of any fruit "pits."
# Vegetables of all kinds
# Meat. Make sure it is well-cooked and that there is no sauce or butter on the meat that could cause them problems. In particular, hermit crabs like to pick meat off of bones. They also enjoy steamed shrimp tails and any sort of dead crustacean.
# Nuts, applesauce, raisins, trail mix, peanut butter, honey, cooked egg, cereal, crackers, washed grass, and popcorn
# Dairy foods may be given to the crabs in small amounts and not too often.
# Frozen fruit and plant-based iguana food
# Escargot (especially good dusted w/spirulina)
# Freeze-dried and sun-dried shrimp and plankton
# Seaweed (normally sold to make sushi or in health-food stores)
# Brine shrimp
# Fish food flakes
# Fish vegetable flakes
This list contains foods that are moderate to high in beta carotene:
apricots
bell pepper of any color, red being the highest in carotenids
blueberries
broccoli
cantaloupe
carrot
chard
cilantro (raw)
collard greens
dandelion greens (raw)
fava beans in the pod (raw)
grape leaves (raw)
lettuce (dark varieties, not iceburg which is nutritionally empty)
mango
papaya
parsley (raw)
passionfruit
peaches
peas
persimmon
pineapple
pumpkin and squash, and seeds (dried)
snap beans (raw)
spinach
spirulina
seaweeds and microalgaes
sweet potato
Astaxanthin is another carotenid found in shrimp and krill and red seaweeds, that the crabs also use.
Tannin is also a color booster. Dried oak or sycamore leaves, or raisins help provide this substance.
List of woods that can be used safely in a hermit crab environment. These are non-toxic woods that wont hurt them if eaten.
Cholla wood
Cork bark
Cypress (swamp variety, taxodium species)
Grape vine
Madrona
Mangrove
Manzanita
Maple
Oak
Pear
Pecan
Sycamore
Unsafe Woods
Apricot
Bitter Almond
Boxwood
Cherry
Cherry Laurel
Eucalyptus
Evergreen of any kind (pine, cedar, redwood, etc.)
Hemlock
Laurel
Nectarine
Peach
Plum
Yew
Molting
When a healthy crab is suddenly overcome with an urge to dig, it is your first clue that a molt might be on the way. Before you assume this, however, check your trusty thermometer and humidity gauge. A tank that is too warm, cold or dry could cause your crab to dig himself a little "microhabitat" under the sand where he is insulated from conditions he does not like. Newly purchased crabs in particular are prone to dig into the substrate for a while. Sometimes they do this only because they want to rest, and sometimes it is because they are indeed molting.
If he buries himself, do not disturb him. It is best for him, if you let him acclimate to his surroundings. Smooth out the sand over and around him then if he decides to pop up at night for a drink or a bite to eat, you'll be able to tell what's going on.
Other moulting signs are general lethargy, less antennae activity, tangled and confused-looking antennae and an ashy exoskeleton or dull-look of their eyes (like a cataract on a human).
A crab that is missing limbs and is nearing a molt will begin the process of regenerating its limbs. The area where the limb is damaged will appear to grow a small nub that looks like clear gel. This is actually the limb encased in a clear chitin sheath. As time goes by and the time for molting grows near, the crab's gel limb will swell and become more defined.
For when a crab moults, you should have a seperate tank for him so the other crabs dont eat him. Ideally it is filled with six inches of soft, moist sand. The sand should be moist enough to make a sand castle, but not so moist that it is drippy. The tank should be large enough to hold food and water dishes also. Fill your tank with about six inches of sand. Then take a jug of water and pour about one cup of water into the sand. Mix it up very well and note how moist the sand is. Can you make a little circle in the sand with your finger without the sides caving in? That is what you are aiming for, a substrate that is moist enough that you can make a little hole like that, which is what you will do for your crabs when they need to molt. Start out with only one cup of water and if necessary continue adding water until your sand is moist and packable, not watery or drippy.
In the food dish you should have a "Molting food" which should have something that is rich in calcium, like cuttlebone, sand dollars, or sea biscuits. For water, give the crabs their regular dechlorinated drinking water. I usually add a bit of saline water to the regular water, because molters need the extra salt to help retain water.
Studies have shown that hermit crabs have two molt-related hormones that enable them to 1) put off molting when the conditions aren't right, and 2) to get down to business when they are! The molt-inhibiting hormone can put into play by numerous factors, but the most important one for hermit crab owners to remember is that hermit crabs have been shown to have better, healthier molts when they are under the substrate, or in complete darkness. This is why if your molters have not been able to dig, why they will molt inside the mouths of larger shells or under tank ornaments.
They store up food and water before they molt. Once they are under the sand, they live on their internal storage. Once they complete shedding, they eat their exoskeleton.
One day you pick up your crab and he falls out of his shell! Molting is probably the culprit. Unless there is a strong fishy odor the crab is more than likely not dead. Note that freshly molted crabs also have an odor, but it is different from and not nearly as strong as the death smell. It smells more like epoxy or iodine. Check the home shell. You probably have a newly molted hermit crab. You can also see if the discard is hollow or crumbles when you squeeze it.
One spritz of water a day onto the molter is the most attention he should receive, and even then you should not pick him up. He needs to be left alone so he can start to regain some energy and to allow the new exoskeleton to harden. Make sure the area you have him in is warm, and quiet and away from active areas of the house.
Immediate isolation from other crabs is highly recommended. Land hermit crabs find the smell of freshly-shed exoskeleton irresistable. They will attempt to climb over and/or tunnel under most isolating devices. Because of this, you should make every effort to remove the molter to a separate tank as soon as possible.
Most healthy crabs molt at least once every 18 months. SOMETIMES smaller crabs molt more frequently, but not always. In a regular molt, it often takes day a day or two for a crab to rest and its claws to harden before it regains the energy to eat its exoskeleton. Pieces of the exoskeleton that are not eaten by the molter should be recycled into the main food dish as an extra source of calcium and chitin. Generally, hermit crabs can be returned to their regular home after they have eaten all the exoskeleton they are interested in eating, and are walking around well.
Species of Hermit Crabs
In the united states, there are 2 species of hermit crabs commonly sold as pets. Caribbean hermit crabs (Coenobita clypeatus) and Ecuadorian hermit crabs (Coenobita compressus). Caribbean crabs have big purple claws and the ecuadorian crabs are more bluish grey colored.
Ecuadorian crabs live on the Pacific seashore around the tidal pools and high-tide-zone. Their bodies have adapted to this seashore existence by becoming able to metabolize the salt in seawater. In fact, theyve adapted so well to their environment that they actually need seawater to live. Caribbean crabs live inland, away from the seashore. They are used to living on whatever falls to the forest floor and they drink from puddles of rainwater.
Shells
Each crab should have atleast 3 empty shells or more. Take your crab in your hand and look at his large claw. The perfect-fitting shell will have an opening about the size of the large claw plus about 1/8" all around (for larger crabs it will be more) or 1/10" all around. You're ultimately looking for a shell whose entrance the crab will be able to plug with his or her large claw and far left walking leg.
Measuring the Aperture (Opening)
Take the shell and put a ruler across the mouth of it. Small crabs require a shell with an aperture of 1/4", larger crabs with 1 1/2" to 2" and up. All shells you give to them should be boiled on the stove at a rolling boil for about five minutes, the allowed to cool. If you have an especially beautiful shell that you're excited about giving to the crab as soon as possible, you can boil it, and then after the required five minutes, gradually pour off the boiled water while you pour cold water into the pot. This will cool down the water (and thus the shell) faster so you can give it to your crab.
Crabs are drawn to shells with circular openings, an exception to this is the Ecuadorian crab. from looking at your Ecuadorian crabs, their head and body are much flatter and wider than a Caribbean crab's. So the Ecuadorian crabs prefer a shell with a slit-shaped opening. Hermit crabs are also drawn to shells lined with mother-of-pearl. It is suspected that they like these types of shells because (1) mother-of-pearl is an excellent insulation from the environment, and (2) mother-of-pearl is very smooth and 'comfortable' on a crab's abdomen.
Light
Hermit crabs require atleast 12 hours of light a day. They do best with full spectrum lighting.
Heat
It is best to have both an undertank heat pad and a low wattage heat light on one side of the tank. This allows crabs to thermo-regulate. That means the crab can choose to warm up or to cool down by moving to oposite sides of the aquarium.
Cleaning
Daily: Clean water dishes and replace water.
Spot clean for Droppings
Remove fresh and/or spoiled food, clean dishes.
Rinse out sponges
Weekly: Clean or replace any decorations that have gotten damaged or overly wet.
Rinse, wash and replace all dishes bowls and the sponges.
Spot clean and sift sand well.
Clean all extra shells (This is done by boiling)
Monthly: Deep clean:
Remove all crabs and place into large bin or extra tank. This is a good time to offer extra shells, smelly foods like silversides and water bins to bathe in. Allow them this time to exercise.
Take out all decorations and bowls/dishes and, wash, boil and or bake to sterilize, allow to fully dry. Do not use soaps or chemicals, but you can use vinegar or hydrogen peroxide, rinse well.
Wash down all glass including lid with a hot water and vinegar solution and then rinse very well until there is no smell left.
Replace substrate with new, clean and fresh. Replace all decorations, hidies and bowls full of fresh waters and foods.
Inspect crabs for mites and injuries. Now is the time to bathe if you choose to do so and then allow them time to dry. Return crabs into their crabitat after doing a full head count.
