A stag beetle whose left side is male and right side is female on display at the Dragonfly Nature Park in Shimanto, Kochi Prefecture (Masatoshi Kasahara)

Photo/Illutration A stag beetle whose left side is male and right side is female at the Dragonfly Nature Park in Shimanto, Kochi Prefecture, on Sept. 28 (Masatoshi Kasahara)

SHIMANTO, Kochi Prefecture--At first, Hiroshi Yokota didn't notice anything unusual about the stag beetle he was raising, but once he did, he felt the world had to see it.

The rare beetle, whose left side is male and right side is female, has become a big draw at the Dragonfly Nature Park here.

Only one in 40,000 of the moseri golden stag beetle is likely to possess the trait, according to a park representative.

“It took me a month to clue in," said the 70-year-old resident of Moriguchi, Osaka Prefecture, of the critter that emerged from pupa in June. "I noticed it had somewhat unbalanced jaws.”

Life forms with that characteristic are known as gynandromorphs.

The species is officially known as Allotopus moellenkampi moseri, normally found in Indonesia and Malaysia.

The 4-centimeter-long body of the beetle on display is divided clearly between male and female from the center.

While the left side of its jaw is long, the right side is short.

Yokota, who is a member of an organization that runs the park and protects dragonflies and nature, decided to gift it to the park so more people can see it.

Inside its display case, the beetle eats jelly for insects and inches its way along scraps of wood.

Koharu Yabe, 5, a kindergartener from the area, was impressed.

“It's shaped differently from ordinary beetles. It's great!”

“It is quite unusual," said Mitsutoshi Sugimura, managing director of the preservation group to which Yokota belongs. "I hope people connect with the mystery of nature when they see it.”

Initially, the display was to end Sept. 29, but has been extended until the end of October thanks to the beetle's popularity.