What went wrong?

[stevenc]

Hi all,
I have a 10 gallon tank with 5 crabs. 3 medium ruggies and 2 jumbo strawberries.
For the past weeks 2 ruggies and one straw went under. The other straw keeps digging the surface.

Yesterday, I found an empty shell of my ruggie on the surface. I dug around and found light orange limps, BP around. I dug a little more and found the body. It was still moving!

I took it out and dug all the way to the bottom and found the exoskeleton.

Any idea what happened?

I don't wish this to happen again.

Also when hermies molt underground, I know they construct a cave. Do they have to come out completely from the shell to molt?

[singlemomwithcrab]

What you found was freshly molted crab. Iso him immediately, fill out this form and post in Emergency.

viewtopic.php?f=27&t=46102

Just a heads up...your tank is VERY undersized for the crab species you have. The smallest recommended for Strawberries is a 55 gallon tank.

viewtopic.php?f=51&t=92450

Where are you located? US or abroad?

[stevenc]

Hi,
Thanks for your reply .
I stay in tropical Singapore, where hermit crabs can be found on the beaches.
Yes I think the tank is undersized but as I stay in an apartment I cannot afford the space.
I made levels for my crabitat and limit it to 5 crabs.

Sadly the guy is dead. I suspect it's an attack during molting.

I am wondering if the crab can retract back into the shell during molting and is its abdomen exposed during molting? Does it have to leave its shell? Or is it being dug out by the attacker?

[CallaLily]

They stay in their shells to molt. It does sound like an attack with the shell, limbs, crab, and exo in different places. Poor little guy.

I agree, your tank is way overcrowded for the size and species of crab you have. How deep is the substrate? I know its impossible to achieve in a 10g but Jumbo crabs need a minimum of 10 inches of substrate to dig and molt in. I do believe the overcrowding may be at least part of what went wrong. If you share the rest of your crabitat conditions, answering the questions Singlemomwithcrab linked, we can help you check if anything else may be off. I'm so sorry for your loss.

[stevenc]

Thanks Callalily for replying.
Since they molt with their adomen in the shell, does it mean the abdomen doesn't shed any exoskeleton?

My substrate is about 6 inch.
Maybe my definition of jumbo might be wrong.
The big ones are slightly less than 2 inch and the medium ones are .75 inch diameter (if you imagine its a ball size)
Now there are 2 big straws and 2 medium ruggies.
I don't wish this to happen again.
Maybe I should put them in ISO tank before they molt?
But it's hard to guess when they want to molt. Most of the times once they start digging in, they will not come up until they are completed with molting.

[CallaLily]

So it sounds like your Straws are small-medium and the Ruggies are teeny-small on our sizing chart. So still overcrowded for size and species kept but not as extreme as I first thought.

The molting process is explained in this thread: viewtopic.php?f=23&t=92527.

Figuring out the size of your crabs and space needed is talked about here: viewtopic.php?f=26&t=92541.

More great info on hermit crab care can be found in this section: viewforum.php?f=51.

[stevenc]

Thanks for the valuable inputs.

I will see what I can do with the exisit ing set up.

Btw, which species of hermit crab don't grow too big and demand the least space?

[megmaholm]

Any crab species can potentially reach softball size. Once they reach extra large or jumbo, I would say the minimum size tank they need is a 55 gallon. Purple Pinchers can tolerate being a bit crowded, but they still need plenty of room to molt and move around. Exotics like strawberries definitely need a LOT of space. A 10 gallon tank won't hold very many crabs of any species, as they grow quickly. I would get as big a tank as you can, for their well-being. They need to be able to molt safely, and have lots of room to climb and explore. It's our responsibility as hermit crab owners to do what we can to replicate their natural environment, hence the deep sand, high humidity, and plenty of living space.