Kurage Wonder Research Team Observation Journal / White Jellyfish

Kurage Wonder was established in 2020. Here you can encounter around 30 different types of jellyfish.
Jellyfish have a wide variety of characteristics. By learning about the highlights of each species, you may be able to find your favorite jellyfish.

A lovely jellyfish from the north

A fragile looking jellyfish circling a small aquarium tank, its short tentacles floating from the edge of its umbrella. This jellyfish prefers cold waters and is found in areas north of the Tohoku region of Japan.

Known in English as the "umbrella jellyfish," it has a slightly rounded triangular shape when viewed from the side, and if you think of the mouth extending from the center as a handle, it looks just like an umbrella. With a small body only about 3cm in diameter, it looks very cute and cool as it flutters around in the aquarium.

[Fluffy floating white jellyfish]

The Fate of the White Jellyfish

White jellyfish are relatively easy to breed, and they can produce large numbers of baby jellyfish. Even as adults, they only grow to a reasonable size of about 3cm, so they are often used as food for jellyfish-eating jellyfish. Large white jellyfish are highly sought after, and are swallowed whole by creatures like the Amakusa jellyfish and Aequorea victoria.

As someone who has raised them since they were babies, I have mixed feelings about them, but I believe they are fulfilling an important mission by providing food for the lives of many jellyfish.

There is also a type of jellyfish sold for human consumption under the name "white jellyfish," but this is a different species from the white jellyfish featured in this column.

The edible "white jellyfish" is the trade name for the Sarcophaga jellyfish , a large jellyfish that grows to about 50cm in diameter. The edible "Japanese sea nettle" is also the trade name for the Sarcophaga jellyfish , and they are called that because they are reddish and whitish in color, respectively, but it can be a little confusing.

A white angel arriving with the drifting ice?

The white jellyfish has a beautiful, transparent umbrella, and the origin of its name is intriguing. Inside the umbrella of an adult white jellyfish is a ribbon-like organ (the organ that produces eggs and sperm, called the gonads) arranged in a cross shape, and the white color of these gonads is the origin of their name.

The fully mature, wavy gonads are often likened to frills, but when viewed from the side, they also look like an angel with its wings down.

In the wild, white jellyfish can sometimes be seen during the season when drift ice arrives.

You can't see the "Angel of the Drift Ice," the Clione, at Kyoto Aquarium, but why not enjoy the white jellyfish, the "New Angel of the Drift Ice"?

For other jellyfish columns, check out #ResearchMemberObservationDiary !