Heikegani or Heike crabs (Heikeopsis japonica) are a species of crab native to Japan. Many of these crabs share a distinctive feature: strange markings on their carapace that have a striking resemblance to the face of an angry Samurai. The crabs get their name from the Japanese epic, The Tale of the Heikes, which records a battle that was fought in Japan’s inland where these crabs are commonly found.

The epic recounts the Genpei War, an event that radically changed Japanese history in the late 12th Century. The war involved the imperial Taira clan (later known as Heike) and the warrior Minamoto clan as they struggled for control of the imperial throne. The Minamoto’s final victory ended the reign of imperial rule in Japan and heralded the event of the Shogun rule with Minamoto Yoritomo, the first military ruler.

The final battle in this story is the battle of Dan-no-ura. While the Taira had retained power through the child Emperor Antoku, years of fighting had left the Taira weak, and their numbers dwindled. The Taira had retreated to their fortress on the island of Yashima, and were holed up there protecting the seven year old emperor. The Minamoto’s landed a small force on the rear of the island, lighting bonfires and making it look like they were staging a full attack. The Taira, thinking the armies were behind them, and worried that the fortress would be breached took to the water, escaping in a number of boats. The attack had been a ruse, and the main forces of Minamoto’s army were waiting for them in a flotilla of ships. While the Taira were easily outnumbered, their skillful archers put in a valiant effort and the forces seemed to be evenly matched.

Unfortunately for the Taira, bad omens started occurring; a white banner unfurled itself from the heavens upon a Minamoto boat, and a number of dolphins swam towards the Taira. These omens all portended to the defeat of the Taira, and so a number of their allies deserted and betrayed them. Knowing that they were facing certain defeat, the Emperor’s grandmother took the young child in her arms and slipped quietly off the boat, preferring drowning over capture. Many of the Taira Samurai followed suit, leading to a Minamoto victory.

The crabs, which are native to the inland sea (the location of the battle) are thought to be the re-incarnation of the many Samurai who died that day. The locals refuse to eat the crabs that are marked with faces (not all are), throwing them back into the sea. Carl Sagan famously did a piece on his show Cosmos on the crabs, claiming that they were a perfect example of artificial selection; after all, not being eaten makes spreading one’s genes easier. While Sagan’s theory has garnered criticism, one thing is certain:

A resounding battle cry for many vegetarians is: “I don’t eat food with a face”,  and luckily for the Heikegani crabs, the inhabitants of the inland sea have taken that gustatory sentiment to heart.

Title Picture Credit: Utagawa Kuniyoshi