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Saltwater hermit crabs are some of the cutest little guys you can keep as pets as they are intelligent, friendly, and curious. There are some eight hundred hermit crab species, divided into marine and land types. The marine ones live their lives submerged in water, so they must be kept in a warm water marine reef tank in captivity.
Certain species of saltwater hermit crabs can live on land but still need ready access to fresh and salt water. Some are more terrestrial than others, but all carry water in their shells to survive. They drink fresh water, but salt water is vital to their metabolism and keeps their gills moist.
Land hermit crabs live out their lives primarily on land, but they need regular, frequent access to saltwater and chlorine-free fresh water. You have probably seen these little critters on the shoreline, feeding at the water’s edge.
This article looks at land hermit crabs and how to keep them as happy, healthy, rewarding pets.
Which Saltwater Hermit Crabs Live on Land?
The terrestrial, Coenobita family of hermit crabs consists of fifteen species. They are land dwellers that lay their eggs in seawater to breed. Those most commonly kept as pets include –
Ecuadorian Hermit Crab (C. compressus)
Fondly known as “Eccies” or Pacific crabs, these crabs have one large pincer, a small pincer, and antennae in addition to their eight legs. The upper part of the bigger claw has four or five little ridges. They are typically tan in color but can also be orange, yellow, or dark gray, and their eyes are shaped like commas.
Eccies are native to Chile and Ecuador and inhabit Pacific coastlines, scavenging dead fish, seaweed, and other organic remains that wash up on the beach. They need seawater for salt, necessary for their metabolism, and to keep their gills wet. Some species can live for more than thirty years in captivity if adequately cared for.
If they don’t have access to saltwater, most species will die. Like all crabs, they molt periodically as they grow. For this, they like to burrow into the sand because they are most vulnerable when shedding their skin. To be happy, they need other crabs for company as they are highly social.
Some of them have a greenish or bluish tint on their legs or bodies, and they are more active than Caribbean hermit crabs. Unlike Caribbean crabs, Eccies need saltwater to survive and fresh water to drink. Caribbean crabs can manage with only fresh water, but good owners try to keep their habitat as natural as possible by providing saltwater as well.
Australian Land Hermit Crab (C. variabilis)
Australians call this little critter the “Crazy Crab,” and it is native to Australia and New Zealand. Their color ranges from sand to light brown to red, with red being more common. When kept as pets, they are low maintenance compared to other hermit crabs.
They can be distinguished by their hairy claws with dark vertical stripes and short, fat abdomens. Their eyestalks are brown or red, and they have two dark-colored oval shapes at the front of their heads.
The Crazy Crab eats meat, raw vegetables, and the larvae of plankton and grows to a length of forty millimeters. They live in warm tropical areas in mangrove forests, estuaries, and intertidal rocks. Their lifespan is shortened in captivity, but they can live for about twenty years if properly cared for.
Crazy crabs can die from stress in a year if the change in their environment is too sudden, such as being taken from the wild and put in an inappropriate tank setup. They get lonely as these crabs typically live in colonies and will even form social groups with other animals. Australian hermit crabs make lovely pets but need a large enclosure to explore with their fellow crabs.
Crazy Crabs may only be thimble-sized when they are young, but they can grow as big as a tennis ball. If they do not grow, they will die, so the proper environment is essential.
Caribbean Hermit Crab (C. clypeatus)
Also known as the soldier crab, purple pincher crab, or tree crab, these hermit crabs are among the most common in the pet trade. The bigger claw is used for fighting other crabs. It is also used as a shield when the crab retreats into its shell.
The Caribbean hermit crab is a reddish color with purple claws, but just before molting, it turns gray. They eat meat, leaves, and fruit and keep their gills moist by bathing in salt or freshwater but live primarily on land. They can live for forty years in their natural habitat but don’t do so well in captivity.
Their lifespan in captivity can be as little as a few months if not kept under the right conditions. The soldier crab grows to fifteen centimeters in diameter, larger than a baseball. When molting, they need access to seawater and sand or another substrate in which to burrow.
The Caribbean hermit crab has to lay its eggs in seawater and doesn’t breed in captivity. The adult crab lives in wetlands in forests and hides inside small caves and among tree roots where it eats iguana excrement. It can also climb up a tree trunk to eat the soft wood higher up.
Each year, they swarm in numbers out of the forests towards the shore, mating as they go. They can travel over five kilometers or three miles to get to the sea when the fertilized eggs are ready to be laid. At the end of August or early September, the females wade into the ocean under a crescent moon, releasing their eggs.
The eggs have to make contact with seawater to release the crab larvae they hold. Females ensure the seawater reaches the eggs by bathing them in the water over a three to four-day period. Then they all turn and migrate together back to the forest.
Indonesian Hermit Crab (C. brevimanus)
The Indonesian hermit crab can grow to the size of a coconut and lives between twelve and seventy years. The fertilized eggs develop inside the female’s shell until they are ready to be released into the sea. They migrate inland and may be found more than one hundred meters from the coast.
They prefer to feed on fish rather than fruit and, in the wild, will prey on smaller species of hermit crabs such as C. rugosus. This is worth bearing in mind when keeping them with ‘Ruggies’ (see below). However, they are omnivores and will eat a variety of foods. They are docile, shy, and safe to handle when kept as pets.
Indos, as they are known, are far less common in the pet trade than the Caribbean and Ecuadorian hermit crabs. They are the most terrestrial of the hermit crabs but still need salt and fresh water. However, they don’t like being wet all the time, so their habitat needs dry areas they can climb onto.
They have one substantial lilac-colored claw that they present to the world when tucked into their shells. Indos can be distinguished from other hermit crabs by their long thin eyestalks
Ruggie (C. rugosus)
Ruggies or “Rugs” are native to Australia, Indonesia, and East Africa. They vary in color, depending on their diet, but commonly occur in brown, green, and tan, with pink, peach, black and white being slightly rarer. These hermit crabs have sandy-colored eye stalks, and they are relatively small – around fifteen millimeters.
Their larger claw has a series of diagonal lines running down the middle that look like stitches. However, Ecuadorian crabs also have these markings, so they can be confused with Ruggies. These tiny crabs need access to plenty of saltwater and a large tank to explore.
They also need sand or another substrate to burrow into for molting. When feeling threatened, Ruggies make a chirping noise by rubbing their big pincer against their shell. They are busy, inquisitive, intelligent, and social and a favorite of many crab keepers.
Ruggies are also omnivores and are not as common as the Ecuadorian and Caribbean hermit crab pet species. They have elongated eyes and a more uniform color than Ecuadorian crabs. Their orange antennae are a distinguishing feature.
Cavipe Hermit Crab (C. Cavipes)
Cavipes have bright red eyestalks and antennae and commonly occur in shades of orange or purple. Another distinguishing feature is a stripe along the larger claw. These crabs are found along the shore and in sheltered lagoons and mangroves
Like most other terrestrial hermit crabs, they need frequent access to saltwater to replenish the stores in their shells. Because of their high salinity needs, they are confined to the seashore and don’t travel far inland.
They come from East Africa, Japan, Taiwan, Malaysia, the Philippines, China, and the Indo-Pacific. Cavipes typically have brown or blue-grey bodies with lighter coloration at the pincers. Their eyes are black and shaped like commas, and there is some orange on the lower section of their second antenna.
They have been known to cannibalize Ruggies and smaller individuals of their own kind. They feed on bird droppings, dead fish, and rotting vegetation at low tide in the wild. When the tide is high, they climb up onto the mangroves.
Strawberry Hermit Crab (C. perlatus)
Strawberry hermit crabs have bright red bodies, but their color wanes if they don’t get enough carotene in their diet. These crabs are not generally recommended for beginners as they are very delicate. They need a lot of tank space to move around and a large bowl of seawater to swim in.
The temperature has to be kept constant for these guys to survive. They require temperatures consistently above eighty degrees. Adult strawberry hermit crabs typically grow up to eighty millimeters. Their eyes are deep black with an opalescent sheen which distinguishes them from other crabs.
They tend to die more often after molting due to attacks from other crabs, so they need a deeper substrate – between ten and twelve inches. When conditions are right, they are very active and like to dig into their substrate. Humidity levels have to be above eighty percent at all times.
Generally, strawberry hermit crabs don’t live long in captivity, on average between one and three years. Molting is highly stressful for them, and they will die if disturbed during the process.
Land Saltwater Hermit Crabs’ Environmental Requirements
Land hermit crabs live in very wet environments because they have gills that must be constantly kept moist to breathe. They can hold a small amount of water in their shells for this purpose, but when it is used up, they have to refresh it. Thus they can’t stay out of water indefinitely.
If they don’t have access to water, their gills dry out, and they slowly suffocate. In the wild, hermit crabs use rock pools and seawater from the waves to gather water for their shells and keep their gills healthy. They only lay eggs in seawater, so they don’t breed in captivity.
They also need places to explore, plenty of obstacles to climb on and shelter under, high humidity, and warmth. At a minimum, two small crabs need a ten-gallon glass fish tank to live in, but ideally, it should be much larger to accommodate them as they grow. You can keep around fifteen hermit crabs in a tank ninety centimeters long.
A commercial hermit crab food is available, but it must be supplemented with little bits of fish, boiled egg, meat, and fresh vegetables. Hermit crabs also need extra calcium to grow their exoskeletons and access to salt and fresh water. Natural sponges are good for keeping the humidity up and preventing small crabs from drowning in their water dishes.
The crabs drink fresh water but need salt water for bathing, so two water bowls, preferably not metal, are required. They can’t drink chlorinated tap water, so you have to boil their fresh water and let it stand until cool. The tank must be cleared daily of old food scraps they haven’t eaten.
The temperature must be between twenty-four and twenty-seven degrees Celsius as they are coldblooded and cannot thermoregulate themselves. The ideal heat source is a heat mat, such as that used for reptiles, buried under the sand and connected to a thermostat. Heat lamps aren’t suitable as they dry out the tank, killing the crabs.
Hermit crabs usually eat their molts, so don’t remove these from the tank. You need to regularly mist their environment to keep the humidity high enough. Land hermit crabs will drown if submerged in water since they are not adapted to live underwater.
Hermit crabs climb surprisingly well, so keeping a lid on their tank is necessary. They are typically nocturnal animals and come out to feed at night and replenish their shell water supply. They need company because they are highly social animals that often live in large groups, so you should never own just one.
Establishing a basic setup isn’t difficult, but you will have to give them daily care and attention. You have to be watchful to stop fights from breaking out as they compete for shells and other resources. Larger ones may attack smaller ones, and some species are cannibalistic despite their social nature.
Shells For Hermit Crabs
The availability of new shells is vitally important to hermit crabs because they need protection for their soft abdomens. In the wild, competition for just the right shell is fierce, and they will fight other crabs for them. The same will happen in a tank, so ensure plenty of empty shells are scattered about.
Some hermit crabs prefer turbo-shaped shells, while others like more tubular ones. They can be very fussy when selecting a new shell, sticking their larger claw into it to inspect its suitability. The opening must be the correct shape and size, and they usually roll it over to clean out any debris inside before moving in.
With hermit crabs, buyer’s remorse is a thing, so they hold tightly onto their old shell while probing a new one. This is to prevent other crabs in the vicinity from stealing their current shell before they are ready to move house.
Saltwater terrestrial hermit crabs can live on land, unlike their marine cousins but need high levels of humidity and warmth to thrive in captivity. They require plenty of access to fresh water and salt water, and large heated tanks to roam freely.
Some species can live for up to thirty years, but they are not as simple to keep as people make out and often die after just a couple of years due to their owner’s ignorance.