Holding an Southern Horseshoe Crab by its tail, clearly shows the horseshoe-shaped carapace, that give these creatures their name. These crustacean-like arthropods have stiff and pointed tails, which are angular in the southern species and rounded in the mangrove species.

The underside of these Mangrove Horseshoe Crabs shows them as in the way they swim, i.e. upside down.