You need to be more specific in what type of blue crab you are referring to. There are at least three different species of crab commonly known as blue crab.

• Atlantic Blue Crab (Callinectes sapidus)
• Blue Crab (Portunus pelgaicus)
• Japanese Blue Crab (Portunus trituberculatus)

The blue crab is a general term that refers to four different species that share similarities:

• The blue king crab (Paralithodes platypus)
• The blue swimmer crab (Portunus pelagicus)
• The Japanese blue crab (Portunus trituberculatus)
• The Chesapeake/Atlantic blue crab (Callinectes sapidus)