mithrax crab question

[cutnup]

What if any (besides color) are the differences between an emerald crab and a red mithrax crab?

 

[Guygettnby]

the only difference i have personally noticed is that the red mithrax crab tends to eat some coraline algea were as my green mithrax tends to stay around the macro algea and scavenge more for food.

i think that is just my personal observation though. i have never asked the difference as i never though there was besides color. they are both mithrax crabs.