The Caribbean Hermit Crab, or Purple Pincher, (Coenobita clypeatus) is the most popular species of land hermit crab that is kept as a pet. Native to Bermuda, Florida, Venezuela, and throughout the Carribean Islands, they are born in the ocean and then adapt to live on land. After this adaptation, they can no longer be submerged into water or they will drown. Their gills (which have been modified to breathe air) must be kept moist to function.

Hermit crabs most likely came by their name because of their quick response to pop back into their shell at the slightest hint of danger. Encased in their shelled home with one claw acting as ‘the door’, it would seem they were behaving as a hermit would, desiring no interaction with the outside world! However, their name betrays their nature, and as any hermit crab owner will attest, they are very active and engaging pets.

Hermit crabs are intricately designed, possessing ten legs and two sets of sensory organs. The first set of sensory organs are the antenna (long feelers), which they use to touch and feel, just like a person's hands would. The second set are called antennules, which enable them to taste and smell. Their left claw, usually the larger of the two, is used as the protective covering to the opening of their shell, keeping them safe when a retreat is necessary. Both of the hermit crab's claws are used for eating, drinking, collecting foods and protecting their home (shell). Hermit crabs possess acute eye sight, possibly due to their eyes being located on the very top end of moveable stalks!

One, Two or More?

Despite their name, hermit crabs are very social and prefer to be kept in groups. A single hermit crab left alone becomes inactive, stressed and will have a much shorter life span than those kept in small groups. Be aware that all hermit crabs will disagree from time to time. 

Handling

When handled safely, your hermit crabs will enjoy exploring the 'outside world' (always under direct supervision). Remember when handling your hermit crabs to hold your hand flat, otherwise they may pinch if they feel scared, insecure or stressed. Be gentle and allow them to explore. If they play shy to begin with, be patient and never try to pull your hermit crab out from its shell; to do so would be extremely damaging. Always remember to wash your hands before and after handling your hermit crabs.

Longevity

With the proper environment and nutrition, your hermit crab's life expectancy can be 10 to 20 years or more! The unauthenticated record for the longest living pair of land hermit crabs in captivity is 29 years.

Moulting

Your hermit crabs are crustaceans and have a unique feature in their makeup which allows them to know when conditions are right to moult (grow). This process is essential to the health of your hermit crabs, so conditions should always be ideal. If darkness, solitude, moisture and warmth are available underground, they can proceed with their growth cycle. When your crab(s) are able to burrow underground, and the environment is good, the moult will begin. This process typically takes 4-8 weeks for a medium hermit crab, and shorter (though more frequent) periods for a small hermit crab. During this time, your crab(s) will burrow in the substrate without their shell and will come to the surface once their moult is complete.

To provide a happy, healthy atmosphere for your hermit crabs, Petland recommends the following necessary and fun accessories. They are listed as your pet's Four Basic Needs: Nutritional, Environmental, Maintenance and Behavioural. When these needs are met, along with a caring environment provided by you, your hermit crabs can live long and happy lives.

ENVIRONMENTAL/BEHAVIOURAL

In their native habitat they enjoy tropical temperatures, always nearby to moist sand in order to bury themselves while they moult. With some hermit crabs growing larger than a baseball, the enclosure must be roomy, have plenty of climbing space, areas for digging and bathing, and be kept at the necessary temperature and humidity levels in order to thrive.

Your Hermit Crab Colony's New Home – Setting up the proper “crabitat” is very important for the overall health of your hermit crabs. We recommend a minimum 10-gallon glass aquarium for 2-3 medium sized crabs. A metal screen top is also necessary since hermit crabs are escape artists and will soon disappear from their home unless a secure lid is in place. Whatever size enclosure you choose, including the following environmental elements are essential for your crab colony's health.

Decorations/Plants – Being the nocturnal (active in the evening) socialites that they are, hermit crabs love to interact with one another. You'll enjoy watching their antics - piling on top of one another, climbing high on plants and branches, walking over one another to get into the pool, and more! All of this behaviour is natural, so it's important to provide your colony with the accessories that closely mimic their native environment. Provide them with different types and shapes of driftwood and branches. Plastic plants, and hiding places such as large coconut shells and plastic dome homes are essential to make your crabs feel happy, safe and secure.

Relative Humidity – As previously mentioned, hermit crabs originate from tropical environments, therefore they are accustomed to high humidity levels. A misting bottle, fogger, or automatic misting system all assist in providing proper levels of 75-85%. A humidity gauge is helpful in monitoring this. The enclosure must always have good ventilation.

Temperature/Heating – Hermit crabs are ectotherms, which means they depend on the temperature in their environment to regulate their body temperature. The natural habitat must be laid out wisely in order to achieve the optimum temperature ranges for their health. Temperatures should range from approximately 73ºF (23ºC) on the cool end of the gradient to 80ºF (27ºC) on the warm end.

To obtain these requirements, an under the tank (UTH) heater is required. Instead of placing this heater underneath the aquarium, it must be adhered to the outside of the aquarium on one side (above the substrate line of the aquarium); this will help to heat their environment safely. Placing the heater underneath the tank could be disastrous for a moulting crab.

A dome light with a suitable sized incandescent bulb must also be used, not only for light, but to keep the air temperature controlled and stable for a comfortable environment. Special attention must be made to the size of the incandescent bulb you choose. Bulbs with a higher wattage placed over a small tank may cause a drop of humidity and raise the temperature into a dangerous range for your crabs.

Thermometer – The use of a thermometer is the only way to know if the enclosure is  being maintained at the correct temperature. Stick-on thermometers are useful, although for accuracy a digital electronic thermometer is better. Place one thermometer towards the warmer end, and one at the cooler end, to monitor the temperature gradient.

Thermostat/Dimmer – A thermostat is used to regulate the temperatures of a heat mat or light fixture that does not have the ability to reduce its own heat output. This safety feature is important to prevent burns, particularly if its possible for the hermit crab to come in close contact with a heat mat. Some light fixtures are equipped with a dimmer, but if not then some thermostats can help regulate heat intensity to prevent overheating the hermit crab. Be sure to use dimming/pulsing thermostats with bulbs only, as on/off varieties can shorten the lifespan of the bulb.

Shells – Since they are always in pursuit of the “perfect” shell, they may fight with one another to steal or rob them of their home if a suitable empty shell cannot be located. Since the opening size and shape of the shell must be able to fit their body, your crabs will need to have a variety of different sized shells available for them to choose from. Shells are sized by their openings and not the overall size of the shell. Your hermit crabs will grow slowly, so choose shells that are close to the same size or slightly larger because if their new home is too big, they won’t move in!

NUTRITIONAL

Food Sources – Hermit crabs are omnivores, which means they eat plant and animal proteins. In fact, as scavengers your crabs will eat almost any food material. In order to house a healthy crab colony, their diet must be kept nutritionally sound. Commercial hermit crab food is the most convenient and easiest way to feed them their basic, daily diet. You may also offer a variety of fresh fruits and vegetables, grains and meats, (such as cooked, unsalted chicken or fish). Once or twice a week, a treat of freeze dried krill (designed for tropical fish) may also be enjoyed.

Water – Hermit crabs use water not only to drink and bathe in, but also to replenish their shell water (extra water they carry within the back of their shell). By providing both fresh and salt water, your crabs will decide for themselves what they need. Therefore, you will require two dishes: one for de-chlorinated fresh water and the other for de-chlorinated saltwater. A fish or hermit crab water conditioner may be used to remove the chlorine. The dishes must be easily accessible and large enough for your crabs to soak in but shallow enough for them to easily get in and out of. The saltwater bowl is a mixture of water and marine salt mix (used for saltwater fish in an aquarium).  You will need to use a hydrometer to measure the amount of salt you add to the de-chlorinated water. A salinity of 1.018-1.023 is ideal. Alternately, look for Hermit Crab Salt Water Conditioner which creates the accurate salt water environment.

Vitamin Supplements – Calcium powder supplement should be sprinkled on their food with small pieces of cuttlebone offered on the side. Providing both of those items will help your hermit crabs’ exoskeleton stay strong.

MAINTENANCE

Substrate – A mixture of 2:1 Desert Blend or Hermit Crab Sand with Plantation Soil, mixed with warm water to achieve sandcastle-like consistency is ideal for your hermit crabs. The substrate should be 2-3 times deeper than the largest hermit crab in the tank to allow for moulting and help keep humidity inside. Calcium-based sand is not recommended because it does not provide the correct consistency and may become sticky. It is important to make sure the substrate continues to stay moist using a spray bottle filled with dechlorinated water to mist the bottom of their enclosure frequently.

Litter Scoop – A litter scoop will make it easier to remove droppings in the enclosure, including perishable food that the hermit crabs will track around the enclosure. Spot clean often to keep his home clean and free from fungus, mould or parasites.

Please ask your pet counsellor what other items pertain to your pet's needs.

Cleanliness and Safety

All pets can potentially carry diseases that may be contagious to people. Young children, infants, pregnant women, people with compromised immune systems and the elderly are at greater risk of infections and should use caution when in contact with pets or their environments. Regular cleaning of your pet’s environment with a pet safe cleaner may help avoid the spread of contaminants.

Hygiene procedures such as washing your hands before and after handling your pet and/or after having any contact with their habitat, is a necessary routine. Children should be assisted with hand washing and always have adult supervision when interacting with pets.

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