Its extremely difficult to tell the sex of your hermit crab. You can only tell for sure if a hermit crab is male or female by looking under her shell. Before you try to figure out the hermit crab’s sex, wait until she is mostly or completely out of her shell.
Hermit crab females have very small genitalia that show when they go most or all the way out of their shells. You may be able to coax her out of the shell if she’s familiar with being handled. If you try to force your hermit crab out of her shell, you could hurt your pet very badly. Instead, wait until she comes out on her own. Then inspect her body for genitalia, known as gonopores. They’re located on the back of her legs, closest to the abdomen and the joint of the cephalothorax. They will look like two tiny holes in her body. Male hermit crabs do not share this trait.
Hermit crabs make for fun and easy pets. Their small size means they don’t require much space, and their unique behaviors are intriguing to observe. Female hermit crabs have some subtle yet distinguishing features that set them apart from males. Read on to learn all about spotting female hermit crabs.
Identifying Female Hermit Crabs
Determining the sex of a hermit crab isn’t always straightforward Here are some tips for identifying females
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Size: Females tend to be a bit larger than males on average. However, size is not a definitive indicator.
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Abdomen Females have a wider abdomen since this is where they carry eggs. The shape may appear more rounded
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Pores Look for two small gonopores (tiny openings) at the base of the rear walking legs These are only present on females.
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Behavior: Females are often more docile and less active than energetic males. However, individual crabs have unique personalities.
Venturing from Shells
The most assured way to identify female crabs is to look for the gonopores. But this requires coaxing the crab from its shell, which they don’t readily do. Be extremely gentle if attempting this, and never forcefully remove a crab.
If you happen to notice a crab venturing from its shell, take the opportunity to check for pores. You’ll need to look near where the abdomen meets the underside. The pores will be visible on either side.
Other Sexing Challenges
Pet stores often don’t know the sex of hermit crabs they sell. Relying on size or appearance isn’t foolproof. Some females may take on masculine features.
Molting also complicates identifying sex. Crabs appear sexually ambiguous right after molting until new shell growth occurs. You may need to wait until features become clearly defined again.
Anatomy of Female Hermit Crabs
Now that you know how to identify female crabs, let’s take a closer look at their anatomy:
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Abdomen: The abdomen of females is broad and domed to accommodate egg carrying. It’s also referred to as the pleon.
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Gonopores: These two small openings on the underside are the female’s sexual organs where eggs are fertilized internally.
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Eggs: Female crabs can produce hundreds of thousands of tiny eggs. They are carried externally underneath the abdomen.
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Legs: Hermit crabs have five pairs of walking legs, with the front pair featuring large claws for defense and food handling.
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Antennae: Long antennae on the head are important sensory organs these animals use to navigate and explore.
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Eyes: While hermit crabs aren’t known for keen eyesight, they do have eyes at the end of eyestalks that can retract for protection.
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Shell: All hermit crabs require an empty snail shell for housing and protection. Females need shells wide enough to accommodate eggs.
Behaviors of Female Hermit Crabs
Female crabs exhibit some interesting behaviors you may observe as an owner:
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Digging: Females dig holes in substrate both for shelter and to serve as nests for egg laying. This natural burrowing instinct is important to accommodate.
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Egg grooming: Female crabs meticulously tend to their eggs, cleaning and aerating them regularly. This maternal instinct ensures optimal conditions.
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Shell switching: As a female crab grows from baby to adult size, she will need to switch shells multiple times to find roomier housing.
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Hiding: Female hermit crabs tend to be more shy and defensive due to their vulnerable egg clutches. Provide ample plants and hides.
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Bonding: Some females may form bonds with other crabs, particularly other females. They can often be seen sitting together.
Caring for Female Hermit Crabs
Female hermit crabs have some special care requirements:
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Substrate: Use a deep substrate at least 6 inches thick. Coconut fiber and coconut husk work well to allow for digging.
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Salt water: Provide both fresh and salt water pools, as hermit crabs utilize both. Salt water supports egg development.
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Diet: Feed foods rich in protein and calcium, such as shrimp, mealworms, and leafy greens. This nourishes growing eggs.
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Shells: Always have a variety of larger shells available so females can easily upgrade homes if needed.
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Rest: Try not to disturb or handle females excessively. They need ample rest during egg incubation periods.
Breeding Female Hermit Crabs
While hermit crabs do breed in the wild, captive breeding is extremely difficult and uncommon. Here’s an overview of the process:
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A male and female pair off and the male fertilizes the female’s eggs internally via the gonopores.
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The female carries up to 1,000 eggs externally under her abdomen for 4-8 weeks as they mature.
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When ready, the female migrates to the ocean to release the eggs for hatching in salt water.
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The eggs hatch into larvae that progress through various planktonic stages over several weeks.
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Eventually they take on a crab-like form, settle on land, and search out empty snail shells.
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Breeding requires an outdoor saltwater setup with gradual land access. Few crabbers undertake this challenge!
Shopping for Female Hermit Crabs
When selecting new female crabs, look for signs of health:
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Active crabs walking around enthusiastically and socializing.
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Intact limbs and antennae and no cracks in exoskeletons.
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Clear, alert eyes with no residue or cloudiness.
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Shells that fit well without openings or crab abdomen showing.
Only purchase crabs from reputable dealers. Avoid crabs that are listless, inactive, or show damage. With proper care, female hermit crabs can live over a decade!
Frequently Asked Questions
Here are answers to some common questions about female hermit crabs:
How can you tell a female crab from a male crab?
Females have visible gonopores at the base of their rear walking legs. They also tend to have wider, domed abdomens for carrying eggs.
Do female crabs need special shells?
Yes, females require roomier shell options to accommodate a growing abdomen and egg clutch. Always provide extra empty shells sized for large crabs.
Do female crabs eat their own eggs?
No. Female hermit crabs demonstrate great maternal care. They regularly groom, aerate, and protect their eggs until ready to hatch.
Can female crabs lay eggs without a male?
No, a female crab needs to mate with a male crab for internal fertilization before she can produce a viable clutch of eggs. Unfertilized eggs will not hatch.
How often do female crabs breed?
In the wild, females likely breed annually. In captivity, successful breeding is extremely rare given the complex life cycle requirements. Most captive crabs do not breed at all.
An Fascinating Pet
Female hermit crabs are interesting pets full of personality. Their reproductive behaviors add an extra layer of intrigue. By understanding the unique features and care needs of females, you can keep them happy and healthy for years to come. Be sure to provide a high quality habitat tailored to their natural instincts.
Determining a Male by his Body Hair
Men can be told apart from women by the amount of hair on their bodies, though this isn’t completely proof. Females have very little hair on their bodies, compared to male hermit crabs. If he is covered in lots of tiny hairs, there’s a good chance he’s male. You can be sure of this by getting him to come out of his shell and making sure he doesn’t have gonopores.
Determining a Female by her Eggs
You can instantly determine if a hermit crab is female if she’s carrying eggs. Hermit crabs will mate by partially leaving their shells if you have both male and female ones. But only if you keep them separate. Male and female hermit crabs that are kept together in captivity will not mate. The male deposits spermatophore into the female, thus fertilizing her eggs. The female will then carry the eggs on her body for a period of one month. There is no doubt that your hermit crab is a female if you see a cluster of reddish brown eggs around her body.