You may find lost limbs lying on the tank’s substrate. Unfortunately, hermit crabs willfully shed legs, and even chelipeds, with some regularity. These limbs shouldn’t “fall off” but can be severed.
The most common reason hermit crabs shed or remove legs is stress. They may sever a limb following injury to escape a fight with a conspecific, ease a mite infestation, or remain in a too-small shell. Hermit crabs rarely worry about losing a single leg as limbs regrow during molting.
For most hermit crabs, temporarily losing a leg is preferable to experiencing prolonged discomfort. Hermit crabs can contentedly move around a habitat after losing a single leg but should only shed one limb at a time. Something is amiss if your hermit crab is short by two or more legs.
Is it Normal for Hermit Crabs to Lose Their Legs?
It may go too far to call it “normal” for hermit crabs to lose legs, but it isn’t rare.
Most hermit crabs shed at least one limb at some stage. This could be one of the eight rear legs or even one of the chelipeds.
A leg on the substrate doesn’t necessarily mean a terrible fate has befallen it. Find out why a hermit crab chose to shed a leg, and determine if this was by choice or necessity.
Can Hermit Crabs Grow Their Legs Back?
Hermit crabs can regrow lost limbs during a scheduled molt, so they’re less concerned about shedding their legs than we think they should be.
When a hermit crab loses a leg, it’ll start regrowing immediately, appearing as a gel-based bud at the base of the lost limb.
Once the next scheduled molt is complete, the hermit crab will regrow its leg or claw, though it may take a second molt to reach full size.
As explained by the Journal of Crustacean Biology, not all hermit crabs regenerate limbs at the same pace. Some species have superior regenerative abilities than others.
However, the number of shed limbs won’t influence how long the process takes. Three lost legs regrow at the same pace as one lost leg.
Why Do Hermit Crabs Lose Legs?
The main reasons for hermit crabs to lose their legs are as follows:
Stress is a common concern for hermit crabs, who often struggle to adapt to life in captivity.
All hermit crabs will experience post-purchase syndrome (PPS), during which they spend prolonged periods hiding. In times of extreme stress, they may also shed limbs.
PPS typically only lasts a few weeks. If your hermit crabs have emerged from the substrate, spent time in the open, and started shedding, their stress has an alternative cause.
Inappropriate Tank Conditions
Unacceptable living conditions are the most common explanation for stress in hermit crabs. Hermit crabs take naturally to life in captivity, and you need to replicate their natural habitat by doing the following:
- A temperature of around 80OF and humidity level of 80%.
- Enough substrate for your hermit crabs to dig and burrow.
- A tank large enough to provide each hermit crab with its territory.
- Variety in a diet that offers plenty of calcium and protein.
- Toys and climbing apparatus to stave off boredom.
If you don’t meet these standards, hermit crabs are likely to grow upset, leading to shedding limbs.
Handling can sometimes be necessary for hermit crabs, but avoid handling them unless it’s essential, as it can be a frightening experience. If you hold a hermit crab inappropriately, it may shed its legs.
When you pick up hermit crabs, do so gently and slowly. Pick up the hermit crab from behind, and keep the skin of your palm tight to avoid pinching.
Get the hermit crab from A to B, and never leave its legs dangling in the air.
Hermit crabs may choose to shed limbs following injury. If a leg or cheliped has been damaged, it may decide to remove it and wait for a replacement to grow during the next molt.
Falls from Height
Hermit crabs love to climb for recreation, often scaling the walls of a habitat. Some hermit crabs will also hang from the ceiling of a tank and fall asleep. If the hermit crab falls, it could injure its leg.
If the leg is broken and useless, a hermit crab may choose to sever it. Minimize the risk of this outcome by packing the floor of a tank with substrate. Ensure you provide at least six inches of substrate.
Fights with Other Hermit Crabs
While hermit crabs get along, they sometimes fall out. Hermit crabs may attack each other in territorial disputes, battles over the right to a shell, or confusion caused by overstimulation.
As many hermit crabs aren’t naturally aggressive, these antagonistic interactions can be stressful. If a hermit crab doesn’t want to fight, it’ll hide in its shell.
If the aggressor is persistent, the victim may shed a limb to distract an opponent before escaping.
Mites can attach themselves to hermit crabs’ legs, driving them crazy with itchy discomfort.
Florida Entomologist explains that the Anereynetes Coenobitus mite is most commonly associated with hermit crabs. These parasites thrive in an unclean habitat, so regular cleaning is recommended.
If mites attach to hermit crabs, they’ll look to ease their discomfort by bathing regularly. If this doesn’t work, the hermit crab may sever their legs to relieve the constant irritation.
In extreme cases, the hermit crab may even sever its eye stalks.
Hermit crabs take their choice of shell seriously, and once they find a shell they like, they’ll fight to keep it. Some hermit crabs will remain in a shell growing too small following an expansion in mass.
If your hermit crab appears attached to a shell that is no longer fit for purpose, do all you can to convince it to change shells. If the hermit crab is stuck, help to ease it out of the vessel. If you wait too long, the hermit crab may sever limbs or claws to still fit inside.
Preparing to Molt
If you’re wondering, “do hermit crabs lose limbs when molting? “the answer is no, but they may shed immediately before doing so.
If a hermit crab feels that a leg is weak, injured, or otherwise useless, it’ll be removed and replaced.
If your hermit crab willingly severs a leg, look for other signs of an impending molt, including:
- A glazed and glassy look in the eye
- Eating and drinking more than usual
- Digging to excess
- Lethargy and laziness
This limb should regrow during the next molt, so the hermit crab may consciously choose to remove a leg that’s no longer fit for purpose.
What Happens When Hermit Crabs Lose Legs?
While hermit crabs can still live long and full lives after losing a limb, shedding one or more legs can result in some ungainliness of movement.
As the Journal of Experimental Biology explains, hermit crabs mainly use the middle six of their ten legs for movement. The front chelipeds are used for eating, climbing, and self-defense, while the rearmost legs are primarily used for grooming.
Shedding the middle legs, whether on the left or right side of the body, will lead to the greatest difficulty in locomotion. A hermit crab can still move around but may become clumsier.
The smaller the hermit crab, the more it will struggle to walk after shedding limbs. Larger hermit crabs have a longer stride, so they can still cover the ground with a loping gait.
What to Do When Your Hermit Crab Loses a Leg
If your hermit crab loses a single leg, consider why this may be. Take action to prevent shedding from becoming a regular occurrence, such as cleaning the tank to clear any parasitic infestation and ensuring your pet hermit crabs co-exist peacefully.
If a hermit crab has lost multiple limbs in a short space of time, isolate it in a separate tank. There’s a strong possibility that the hermit crab is unwell, and whatever ails it could be contagious. Alternatively, the hermit crab may be struggling to live with conspecifics.