If you think of a crab as a pet, there will be a hermit crab in the first few names. This is how popular they are. They have some interesting characteristics that make them completely different from other crabs. There are over 800 species of hermit crab but only 15-20 are kept as pets with two popular species one being the Caribbean or purple pincher other being the Ecuadorian hermit crab. Here you will learn about fascinating hermit crab facts.
Not true crabs
An interesting fact about hermit crabs is, they do not have the same body as other crabs. The front part of a hermit crab’s body, known as the cephalothorax, is covered by this exoskeleton, and the abdomen does not grow exoskeleton keeping the vulnerable body. This part of the body is curved and vulnerable. The overall structure of the body is more like a lobster.
Dependent on gastropods shell
To protect their vulnerable abdomen from predators and environmental stressors they need to use gastropods’ shell leftover shells. If they do not find one they will use whatever that fits best. In the evolution of time, the external shell becomes like a part of the body. Without that, hermit crabs won’t survive for long.
They deal with anemones
Hermit crabs are known for dealing with sea anemones, especially marine hermit crabs. They place the anemones in their shell when they think only the shell is not enough to protect them. The anemones help a crab to camouflage itself within the coral and give the appearance of an octopus in exchange for traveling with the crab and a scrap of his food.
Dwellers of land and sea
There are two types of hermit crabs land and marine. Marine hermit crabs live their whole life underwater and rarely come out to land. Land hermit crabs spend their 90% of life on the land (only in coastal areas). Most of the hermit crabs kept as a pet are terrestrial.
Modified gills
Land hermit crabs have different gills than marine crabs that adapted to breathe air. These gills are highly vascularized and are capable of extracting oxygen from the surrounding air.
Carry water in the shell
Their gills need to be moistened. If the gills become dry they won’t be able to breathe. The moisture comes from the air humidity and the water stored in the shell, in case the air becomes dry. They also throw this water to scare the enemy.
Can drown in water
It sounds weird how a crab can drown in water. But it is true, that land hermit crabs’ specialized gills do not allow them to breathe underwater. That’s why they go to water occasionally such as mating and hatching eggs. They can stay underwater for 20-30 minutes depending on the species.
Hermit crabs are a social animal
- Hermit crabs are very social animals, they live in groups forming colonies. Occasionally they gather at the seashore and swap shells, this is like a tradition. One crab will leave the shell for the other in exchange for his shell. Win-win for both.
- They perform special dancing-like gestures to attract a female.
- In hermit crab groups, a dominance hierarchy emerges where larger and stronger individuals establish authority over smaller ones, leading to potential conflicts over territories and resources.
Fighting Instinct
Despite being a social animal, conflict arises. They can fight to the death in order to occupy a shell. If the stronger one sees a weaker one has a better shell than him. He doesn’t hesitate to attack. When a predator attacks hermit crabs merge themselves in the shell closing the opening with a claw.
Can grow up to 40 inches
Hermit crabs vary in size depending on the species. They can grow from 0.5 (Coenobita compressus) to 40 inches (coconut crab).
Hermit crabs live longer than dogs
The average lifespan of a dog is 10-15 years. But a Hermit crab can live up to 30 years (depending on the species, some can live up to 10-15 years).
Wide range of colors and patterns
Hermit crabs can vary in a wide range of colors such as blue, orange, purple, yellow, red, and brown, and can be different in shades depending on the species. The colors can be solid or can be striped and dotted in pattern.
Go through molting
For the first 16-20 days of born, they go through five to six stages of molting. The younger hermit crab can molt 3 to 4 times a year, as they grow the process becomes less frequent like once a year. In this period they become more vulnerable to predators. The smell of the molting attracts predators and they can’t even protect themselves because their body becomes weak. So instead they hide themselves for a period borrowing underground. When they come out with a new exoskeleton they eat the old one. Every time they molt, they become larger and need a new shell.
They exhibit nocturnal behavior
Though hermit crabs can be seen during the day they are more active at night. They spend the day hiding and burrowing in the sand. Most of their activity from eating to mating, they do at night.
Very smart creature
Hermit crabs can recognize a person with voice and movement and can be trained with promised food.
Eats whatever they find
They will eat anything that can be eaten. From vegetables and fruits to dead plants and animals they will eat whatever they find even their poop (seems weird tho).
Hard to breed in captivity
Another interesting fact about hermit crabs is they do not have a problem to reproduce in the wild. The process goes normally. But when it comes to reproducing in captivity, they are not interested. Even now the real technique of reproducing hasn’t been revealed. The crabs you see in the shop are taken from their natural habitat.
Great climber
Hermit crabs love to play around and climb. Because of their curiosity, they love to climb and explore things.
Credit: Haridas Vasudevan // Shutterstock
Regeneration ability
Often hermit crabs drop their limbs or if they get attacked and lose their leg or claw, no tension they can regenerate it. But a new claw won’t be as strong as the old one.
Odor can indicate their health
A subtle, earthy, or oceanic odor indicates a normal hermit crab, a sweet and egg smell may indicate a molting hermit crab and a rotten and fishy smell indicates bacterial infection and health issues.
