Is there any such thing as a truly aquatic crab?

[Freshie In Disguise]

In the FW department, I have seen fiddler crabs and red clawed crabs. Some say they are aquatic, some say they are amphibious.

Is there any such thing as a truly aquatic crab?
Having three fiddlers myself, I can tell that they are not aquatic. They spend 60-70% of their time out of the water. I've also switched them to brackish water, and I can't say whether or not it has benefitted them, since the change occurred so quickly after getting them.

So, is there any such thing as an aquatic freshwater crab?

 

[blackomen]

I have a red thai crab( the red clawed guy) and he spends 99% of the time living in the hob filter. Only time he's actually in the tank is when I take the lid off the filter and he jumps in the tank. Not sure of any totally aquatic crabs, not really much help. good luck!

 

[Freshie In Disguise]

I'd like to get some red clawed crabs to mix with my fiddlers but I'm afraid they'd eat eachother. They're just so bright and colorful.

 

[mgamer20o0]

yes there is.

thai micro crab

 

[Freshie In Disguise]

Oh neat. It looks tiny.
My other crabs would eat it.

 

[mgamer20o0]

it is small. smaller then a cherry shrimp

 

[mattrox]

What about the Malawi crab? Potamonautes orbitospinus
Malawi Cichlids in their Natural Habitat 4th edn. p411 picture only.