The mysterious oddities of jellyfish

Fujisawa, Japan - Round, bell-like bodies drifting and dancing through the water — a most relaxing sight that also carries an air of mystery. Jellyfish, those soothing, umbrella-shaped creatures, are aquarium idols that attract many people.

At Enoshima Aquarium in Fujisawa, Japan, jellyfish illuminated in dark blue light swim amid relaxing music in a jellyfish exhibit hall that was renovated last year. The aquarium started exhibiting jellyfish on a permanent basis in 1973 and is now known as a pioneer of raising jellyfish for exhibitions.

Pacific sea nettle jellyfish drift in the water. The sight is so enchanting, visitors may forget about their deadly venom.  Picture: Yomiuri ShimbunSpotted jellyfish are brownish and semitransparent. Picture: Yomiuri ShimbunAquariums specializing in jellyfish sell custard buns and jelly desserts themed on the umbrella-shaped creatures; jellyfish have no taste, but their gummy elastic texture is delightful. Picture: Yomiuri ShimbunAurelia jellyfish rise in the water at Enoshima Aquarium. Picture: Yomiuri ShimbunBlue jellyfish are sold at pet shops for ornamental purposes; blue jellyfish actually comes in various colors such as blue, brown and white _ hence its other nickname, color jellyfish. Picture: Yomiuri Shimbun

It currently exhibits about 3 000 jellyfish from about 40 species in Japan and elsewhere.

“Some studies show that viewing jellyfish can ease mental stress. Their healing effects attract people's attention,” said Aya Adachi, a curator at the aquarium in charge of keeping jellyfish. Asked which jellyfish species are popular these days, Adachi showed me a species called aurelia in an eye-catching globe-shaped water tank that was installed last summer. Aurelia are often seen in waters around Japan.

“It's not showy. It just swims along with the current, opening and closing its umbrella. Many visitors to our aquarium say they feel healed after watching them,” Adachi said. She also said the shape of the water tank was intended to give visitors an impression of gentleness, just as the jellyfish do.

Adachi's next suggestion was the Pacific sea nettle, which has an umbrella more than 30 centimetres (about 11 inches) in diameter. It inhabits the Pacific coastal area of North America and is one of the largest jellyfish species in the world. Seeing them drift through the water with their tentacles trailing softly behind is compelling.

Meanwhile, the blue jellyfish actually comes in various colours such as blue, brown and white — hence its other nickname, colour jellyfish.

“Its chubby shape is cute. It's also agile. These jellyfish are popular among children,” said Adachi.

The brown jellyfish matches its name with brownish tones. Its umbrella is 10 to 15 centimetres in diameter, but its tentacles are about one to two meters long and slowly retract after they snag prey.

“We occasionally feed them during the aquarium's opening hours. So if you're here at that time, you can see it,” she said.

Visitors are allowed to take photos as long as they don't use a flash, so many jellyfish lovers come to Enoshima Aquarium to snap pictures, Adachi said.

A cafe on the second floor sells a custard bun and a jelly dessert both designed after jellyfish.

An increasing number of people are buying jellyfish at pet shops and keeping them at home to enjoy their appearance. However, such owners must educate themselves on jellyfish behaviour and other important factors, such as toxins. A water current must also be generated in the tank using water jet pumps.

“You may have an image of jellyfish as dangerous, but visitors can forget that here and just enjoy watching them,” Adachi said. Once people understand that jellyfish toxins are meant to catch prey, they will probably be more enchanted by their beauty and forget their fears that they are dangerous creatures.

Jellyfish can also be seen at other aquariums across Japan.

The Tsuruoka municipal Kamo Aquarium in Yamagata Prefecture exhibits more than 50 species of jellyfish. It also sells original goods themed on jellyfish, including the Kurageiri Kasuterayaki cake containing sweetened bean paste mixed with drained and processed jellyfish. Jellyfish have no taste, but their gummy elastic texture is delightful.

The cake is a popular souvenir at the aquarium. Yokan sweet bean cake, which also includes jellyfish, is also popular.

Shinagawa Aquarium and Sunshine Aquarium in Tokyo and Osaka Aquarium Kaiyukan in Osaka also entertain visitors with their jellyfish exhibitions.

Midori Yamamura, Washington Post