Hermit crabs tend to spend moments of loneliness and lethargy, especially when they moult; in these situations it can be difficult to tell if your specimen is sick, dying or actually shedding. However, as a general rule of thumb you should proceed in this order: assume he is molting before thinking he is dead, unless it is evident otherwise. Read the tips below to assess the situation and take care of your little friend.
Steps
Part 1 of 3: Check the Vital Signs
Step 1. Smell the area for a rotten fish smell
This is the surest way to tell if the hermit crab is dead; if so, it begins to decompose and the carcass emits a rotting smell. If you can't smell any smell, take the animal out of the aquarium and smell it more closely; if you smell a salty, rotting smell, there's a good chance it's dead.
Step 2. Assume it is shedding
This animal periodically changes its exoskeleton and often loses some parts of its body in the process. The hermit crab remains motionless for some time as it regains muscle control and the exoskeleton becomes stronger. If you disturb him at this stage, you can damage him dangerously, so you must be patient and think that he is going through this process before you think he is dead.
Step 3. Observe it when it is out of its shell and showing no signs of transition
In this case, it may actually be dead or the material you see is not the animal itself, but a mere byproduct of the moult. If you notice something that looks like a dead hermit crab next to the shell, look closely to see if it is the exoskeleton instead; if it is hollow and crumbles easily, it is only the old "shell" of the animal. Look inside and beside the shell for the crustacean that has just moulted and is hiding somewhere.
If it is clear that what you see is not the exoskeleton but the immobile hermit crab, try to tease it to see if it moves; if he doesn't react, he is likely dead
Step 4. Move it and see what happens
If you can't tell if it's dead or not, put it in a different spot in the aquarium and see exactly what position it is in; try putting some food on the other side of the tank and see if the hermit crab is tempted to reach it. Leave it in the container and come back after a few hours to check it; if it has moved in the meantime, it clearly means that it is still alive, but if it has remained still it could simply sleep or moult.
Step 5. Watch him if he hides
It is quite natural for these animals to hide; it means that they are shedding or that they feel threatened. Smooth the sand a little where your little friend is hiding and look at the signs of the path he follows to see if he will want to go out at night in search of food. If it's been a few weeks since he went into hiding, you can loosen some sand around his body and smell to see if he smells bad.
Part 2 of 3: Caring for the Hermit Crab during the Moult
Step 1. Find out if he is actually shedding
If it's out of its shell and not moving, maybe it's changing the exoskeleton; moreover, in this phase it tends to be lethargic, the antennae are less active and appear tangled and disordered, the exoskeleton is pale and the eyes dull (like those of people who have cataracts). It can stand still for a long time and can hide in the sand as a defense strategy.
- Smaller, fast-growing specimens may moult every few months, while larger ones tend to shed their exoskeleton about once a year. Take note of the time elapsed between wetsuits and the length of the process to know what to expect. If you have recently brought your new friend home or have never shed before, you need to wait until you are sure.
- Wait several days. If it doesn't start to smell bad, there's a good chance it's just this step; the moult usually lasts about two weeks, so you can wait this time before drawing any conclusions.
Step 2. Look for a "bubble of fat"
Determine if the hermit crab has eaten a lot in the last few days; before moulting, this animal accumulates extra fat and water in the form of a small black "bubble" - usually on the left side of the abdomen, just below five pairs of legs. However, don't assume it's shedding just because you see this detail.
Step 3. Separate the moulting specimen from the others
During this process the crustacean is more likely to suffer from stress or injury from other animals because it is not active and its new exoskeleton is softer. If one of your friends is actually molting - and you have other hermit crabs in the same aquarium - put him in an "isolation" tank so that he can continue the process safely and discreetly; it is very important that he is not disturbed during this change.
If you only have one tank, set up a "quarantine ward" inside the tank. Cut the ends of a two-liter soda bottle and dip the edges into the sand to protect the hermit crab. make sure the top of the cylinder is open, so that the oxygen on the surface can reach the space below
Part 3 of 3: Disposing of the Dead Hermit Crab
Step 1. Collect the hidden hermit crab and dispose of it if you smell it emitting a rotten fishy smell
To proceed in a hygienically correct way, take it together with the sand in which it is hidden and throw both elements in one go.
Make sure you wash your hands thoroughly with antibacterial soap after handling the corpse
Step 2. Throw it in the trash
If you are comfortable with the idea of throwing the dead crustacean in the garbage, you can simply throw the remains in the bucket along with the other waste. Put the body in an airtight bag, place it gently in the bucket and dispose of it like this.
Step 3. Bury the body
If you can't stand the idea of throwing your little friend, consider burying him about a foot deep in the ground. This is a very personal decision and you have to do what you think makes you feel best in this situation; bury it deep enough to prevent other animals, such as dogs, cats, or other wildlife, from burrowing and reaching its body.
Feel free to bury it along with the sand taken from the aquarium. Since the sand may be contaminated, burying it is the best way to dispose of it properly
Step 4. Do not throw the body down the toilet
This may seem like a quick and easy solution, but it's not a good idea, as the rotting carcass could contaminate the water; just bury it or throw it in the trash.
Step 5. Prepare the aquarium for a new specimen
If you want to replace your deceased crustacean friend, clean the tank before introducing the new animal. Remove any sand that may have become contaminated with the rotten hermit crab, then clean the walls and put in new water.
