Question About A Scarlet Hermit Crab

[Sea Turtle]

Hi everyone.

When I first started my tank I purchased maybe 8 blue legged hermit crabs and 1 scarlet hemit crab. Now that the tank is 4 month old I noticed this morning that there was two scarlet hermit crabs in the tank now.

My question is: could one of the blue leg hermit crabs turn into a scarlet hermit crab, or did the original scarlet hermit reproduce some how?

Also, I am 100% sure I only bought 1 scarlet hermit.

 

[n3ont3tra]

That's pretty weird. Are you sure you didn't just see a molt of the scarlet?

If it's not a molt, then it probably came as a hitchhiker on some live rock.

 

[Sea Turtle]

No, I am sure. It was in a shell that I put into the tank hanging out next to the other one.

How do crabs reproduce then?