The lingering summer heat is still intense, but what comes to mind when you think of summer?
Summer vacation, swimming in the sea, watermelon, somen noodles, the sound of cicadas... There are so many things that come to mind. But if you were asked, "What creature makes you feel like it's summer?", what would come to mind? For me, it's the Mastigias papua.


At the end of July, jellyfish collected at the Iburi Center arrived at the Kaiyukan. They are currently being kept in the back area, and while their bells were about 1cm to 5cm in size when they were brought in, they have grown to about 3cm to 8cm in about three weeks.
One of the most appealing features of the octopus jellyfish is the polka-dot pattern on its bell. In the tank, it moves its bell rhythmically and swims energetically, swaying in the water current. Watching it, you get the feeling that summer has truly arrived.


If you look at the photos, the inside of the tank may appear blue. This is because the tank is being kept under blue light to facilitate photosynthesis by the symbiotic algae living inside the jellyfish. The algae produce nutrients through photosynthesis and pass some of them on to the jellyfish.
Don't you think the sight of a jellyfish floating gently in the blue light evokes a cool, refreshing feeling reminiscent of the summer sea?

We are currently working on developing it for the exhibition. Please wait a little longer until you can see it up close.