Photo/Illutration

Editor's note: This is part of a series of videos offering an up-close perspective on the animal kingdom. A special 360-degree video camera system was set up in zoos and other facilities to show how the animals view their world as they interact.

Also visit our special 360-DEGREE LIVES page (http://t.asahi.com/360lives), where you can watch all the previous videos.

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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 takes pride in being home to a tidal flat that is a breeding ground for horseshoe crabs, which is a government-designated natural monument.

The city-run Kasaoka Horseshoe Crab Museum is housed in a building modeled after the brackish water arthropod.

According to curator Kojiro Azumakawa, the horseshoe crab has a bowl-shaped smooth shell, spiny body, crab- or spider-like legs and a long, stout tail. It is a “living fossil” whose appearance has remained unchanged for about 200 million years. Females are about 60 centimeters long and weigh about 3 kilograms, while males are 50 cm long and weigh about 1.5 kg.

The arthropod is actually not a relative of crabs but closely related to spiders and scorpions.

Their eggs are eaten in some parts of China and elsewhere, but they are unpleasant to the Japanese palate because of their distinctive smell and squishy texture.

“If Japanese people found the horseshoe crab tasty, it might have been extinct in Japan by now,” the curator added.

One thing that makes the horseshoe crab unique is that its blood helps save our lives, he continued.

It is said that its blood runs blue, however, its original color is semi-transparent milky white. It turns blue over time as it undergoes oxidation.

Because the blood turns to gel when in contact with the slightest amount of bacteria, it is used to get quick results for contamination of injections, dialysis and other treatments.

Azumakawa also said that native horseshoe crabs in the tidal flat in Kasaoka were once driven to the edge of extinction due to reclamation, environmental contamination and other conditions. But local officials have been making efforts to protect and breed the arthropod, starting with the founding of the horseshoe crab protection center, a predecessor of the museum, in 1975.

The officials started seeing them laying their eggs in natural settings about 10 years ago, meaning that the city is ready to provide a home to the horseshoe crab again.

Visit the Kasaoka Horseshoe Crab Museum’s official website at (https://www.city.kasaoka.okayama.jp/site/kabutogani/3088.html).