Photo/IllutrationFireflies flutter around a river, blinking in the night sky in Satsuma, Kagoshima Prefecture, on May 15. The photo was taken in a 60-second exposure mode. (Yasuhide Kido)

  • Photo/Illustraion
  • Photo/Illustraion

SATSUMA, Kagoshima Prefecture--Flickering fireflies put on a nocturnal light show by a river here, emitting brief bursts of green against grass and trees on opposite sides of the water.

Tourists in small boats got a glimpse of the glowing insects on May 15 in the first cruises of the season along the Sendaigawa river.

About 70 passengers headed out on the water that evening to view the lightning bugs. Such a boat tour is rare in Japan.

“Genji-botaru,” or Luciola cruciata, account for most of the area's fireflies, according to the town government's commerce and tourism public relations section.

If they're lucky, visitors may also spot ones from the “hime-botaru” Hotaria parvula species, the department said.

The boats depart and arrive at the corner of a park in the Futawatari district. Visitors can closely observe fireflies temporarily resting in the tufts of grass around the dock.

The river cruises are expected to run through the month, ending May 31 at the earliest.