Hermit Crabs Care
Hermit Crab (Coenobita variabilis)
The Australian Land Hermit Crab is endemic to Australia, with a range from northern Western Australia across the top end to North Queensland.
Hermit Crabs are land crustaceans and spend their adult lives on sandy dunes, rocky beaches and mangroves. Hermit Crabs are not recognised as true crabs because they lack a broad flat shell. They have an omnivorous diet consisting of vegetable matter and carrion in the wild. These crustaceans are exceedingly docile and easy to handle, only nipping with their pincers in self-defence.
The setup for your Hermit Crab is very important and the Pisces Laboratories Habitat Kit will ensure you create the correct environment.
Hermit Crabs must shed their exoskeleton through ecdysis, which can be traumatic and thus it’s important to replicate a humid, tropical environment.
Setting up this environment is simple with the Pisces Laboratories Habitat Kit as all the specific elements that are essential to the wellbeing of the Hermit Crab have been included.
Hermit Crab Habitat
The setup for your Hermit Crab is very important to ensure the correct environment is created. Hermit Crabs must shed their exoskeleton through (ecdysis), which can be traumatic. It is important to replicate a humid, tropical environment. Hermit Crabs scavenge for food in the area where the ocean’s tides rise and fall on the beaches each day and for replacement shells.
Setting up a tank is simple, but there are specific elements that are essential. Use a sealed glass terrarium as they are great climbers and can easily escape. It’s important to know that these are a social animal and prefer the company of other Hermit Crabs.
Cover the bottom of the tank with at least a 5cm layer of clean, dry coral sand. Hermit Crabs love to climb and clamber over objects so put in pieces of dried drift wood in the middle to allow the crabs to scramble around.
Humidity, nutrition, water and shells are all equally important to the Hermit Crab. Special food supplements are available where crabs are sold and these provide the essential nutrients required to help the crabs grow. The exoskeleton requires calcium carbonate in order to toughen during moulting phases. Barnacles, sea shells and the cuttlefish shell often seen in bird cages are also good sources for the crabs to chew on. Hermit Crabs drink fresh water but don’t use chlorinated tap water in the tank. They are natural scavengers, provide very small pieces of raw vegetable to balance the diet. Be sure to remove remnants of old food regularly.
Natural sponges, dampened regularly will provide the crabs with another source of water and food and will also provide a source of water to help create a humid environment. Humidity isn’t possible without heat. Hermit Crabs are cold blooded and require an external, constant heat source. An ideal temperature range is between 24-30ᵒC. Under tank heaters work the best. Over-head lamps will only serve to dry out the tank, killing the crabs. Use a small water mist bottle to spray a fine sheen of water on the tank’s sides to provide moisture for a humid environment. The crabs themselves don’t seem to mind a spray too.
Spare shells are vitally important. If you’ve provided the right environment, the crabs will grow. If they don’t grow they will die. Examine the crabs and provide enough shells for each to grow into during its next moult. Use those shells with round openings, not elongated slits. The hole of each subsequent shell should be about 1/3 to 1/2 as large as the crab’s current one. Just scatter the shells around the sand. Once the crabs have regained their strength after moulting, they will hop out of their old shell and search around for another that fits. Leave the old exoskeleton in the tank, it is a source nutrition and the crabs will eat it.
Appearance
Land Hermit Crabs have slightly varied appearance, as they range in size from a thimble to a tennis ball, with shades of colour from pale sand through to reddish tones. Being an arthropod, Hermit Crabs will ‘moult’ to grow. This moulting process requires them to shed the hard exoskeleton to expand and grow larger before their new exoskeleton hardens. Like all arthropods, Hermit Crabs lack a back bone, and have jointed legs. As the Hermit Crab sheds and grows it requires a larger shell to house it increased size. This results in the Hermit Crab searching for more suitable shells and changing into them.
Hermit Crabs obtain their name from their use of shells as permanent housing. Hermit Crabs frequently make use of any empty snail or mollusc shells. Hermit Crabs when frightened or threatened will retract back into their shell with only their legs and claws visible (these body segments a highly sclerotized making them very tough). The Hermit Crabs’ abdomen is always kept protected within their shell, this is because their abdomen is actually not heavily sclerotized and thus is soft and vulnerable.
Life cycle
Adult Hermit Crabs are committed to a terrestrial environment, however their larvae go through a typical planktonic stage. Hermit Crab larvae go through two non-feeding zoeal stages which can take a few weeks before they return to land and enter their megalopal stage.
Life span
Land Hermit Crabs can have a lifespan in captivity of up to 15 years. Though in nature it is believed this species can reach ages of up to 30 years old.
Moulting
Land Hermit Crabs moult their exoskeleton every 2-18 months depending on their age, size and habitat.
Food
Hermit Crabs should be fed a variety of foods to accurately simulate their natural diet. It is recommended that you use fresh fruits and vegetable (blueberries, mango, banana, pineapple, grapes, sweet potatoes, carrots, corn, spinach, apple and broccoli heads), nuts (Walnuts, peanut butter), honey, oatmeal and wheat germ offer a nice change to fruits and vegetables. Meats such as sardines, unseasoned raw beef, blood worms and meal worms can be offered.
Handling
Hermit Crabs should be picked up gently by the back of the shell and placed on an open flat palm. Never pull on or remove a Hermit Crab from its shell home. Be very careful when handling as their pincers can give a nasty pinch. It is not recommended that young children handle Hermit Crabs.