King Crab
King Crabs or Stone Crabs are very large crustaceans chiefly found in cold seas. Because of their size and taste they are fished widely. They are theorized to have come from a hermit crab ancestor which would explain their symmetry but nothing has been proven thus far.
All crabs have the same basic design which is a hard exoskeleton that protects and supports them, this hard shell is called a carapace. Their gills are located in special chambers inside of their shell and the gills are not visible from the outside. Other than the different placement, crabs gills function in the same way as a fish' would except for land crabs who still have gills that can function by pulling oxygen out of the air.
All crabs have the same basic design which is a hard exoskeleton that protects and supports them, this hard shell is called a carapace. Their gills are located in special chambers inside of their shell and the gills are not visible from the outside. Other than the different placement, crabs gills function in the same way as a fish' would except for land crabs who still have gills that can function by pulling oxygen out of the air.