Among the most familiar and easily recognisable is the brown crab (Cancer pagurus) also known as the edible crab, with its chunky, oval-shaped shell and that distinctive crimped, pie-crust edge.

Visitors to JR Kasaoka Station in Kasaoka, Okayama Prefecture, are greeted by a large billboard standing in front that reads: “Welcome to Kasaoka, town of horseshoe crabs.” The city of Kasaoka ...