Fresh water jellyfish of Komae

The freshwater jellyfish in Komae measures between 5 and 25 millimeters in diameter with a translucent body containing up to 400 tentacles around its bell margin.

Scientists first documented this species in the Yangtze River basin of China, from where it spread globally through water bodies, reaching Japan's Tama River.

The designation of these jellyfish as a natural monument reflects Japan's commitment to preserving small yet significant elements of their local ecological heritage.

Visitors can observe these jellyfish during late summer when water temperatures reach 25°C, although their appearance remains unpredictable and depends on environmental conditions.

These jellyfish reproduce both sexually through medusae and asexually through polyps, forming colonies that can survive winter by entering a dormant state called podocysts.

Location: Komae

Address: 東京都北多摩郡狛江村字和泉

GPS coordinates: 35.62889,139.57000

Latest update: March 9, 2025 06:16