Photo/Illutration Garra rufa(doctor fish) (Takeya Toshiyuki)

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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The tickling sensation is intense enough to make visitors cry out when they dip their fingers into a fish tank at the interactive aquazoo theme park Nifrel in Suita, Osaka Prefecture.

The tank contains garra rufa, aka “doctor fish,” so-called because they nibble on dead skin cells with their sucker-like mouths. The tank contains about 500 of the fish, and visitors are encouraged to immerse their hands in the water.

When I tried it, I experienced a pleasant tingling, sort of like low-frequency stimulation. It seemed to me that my fingers attracted more fish than those of other visitors.

“The number of fish varies, depending on the moment the fingers enter the water, the total area they occupy and length and thickness of the digits,” said zoo employee Satoru Miyagawa, 28. "It has nothing to do with the amount of dead skin cells, cleanliness or other conditions."

Doctor fish, a species of cyprinid freshwater fish, grow to between 5 and 10 centimeters in length. They have no teeth.

They can thrive in water temperatures of up to around 37 degrees, and are found in rivers and spas in western Asia.

It is believed that the fish started eating dead skin cells of bathers because it is difficult for moss and plankton--their traditional food source--to take root in spas.

In Turkey, doctor fish spas are used to clean the feet of bathers and treat mild skin diseases.