Spineless, Tentacled, Lovable

Move over, Rover. Trendy pet owners in Tokyo have found a new companion -- the jellyfish.

They don't slobber or bark. They don't leave claw marks on the sofa. And best of all -- they exude calm.

"It relaxes me to watch them float," Miki Koyama, a 28-year-old office worker, said of two doughnut-sized jellyfish floating in a tank at her Tokyo apartment.

The pet jellyfish craze has been the topic of specials on nearly all major TV networks in Japan. Jellyfish have even squished their way onto the pages of the Nihon Keizai Shimbun, the country's leading economic newspaper.

As is often the case here, single women in their 20s and 30s appear to be fueling the fad.

Many cite the creatures' slow, soothing movement in the water as their main attraction. Like living lava lamps, jellyfish are a kind of relaxation-inducing objet d'art.

They aren't a lot of trouble to take care of. And their sting is harmless to humans.

"Jellyfish never disturb you," said Hironobu Fujii, an employee at a Tokyo pet shop. "If you leave the house for a week, it doesn't matter to them. I think that's why they are popular with women who live alone and want to keep a pet."

Along with moon jellyfish, the most popular house-pet varieties are the octopus jellyfish and a jellyfish that appears to be constantly upside-down.

The pet species tend to be small, and are transparent, pale blue or milky white.

They range in price from about $14 to $38 -- a steal in a country where a robust atlas beetle can fetch thousands of dollars.

While a jellyfish might seem an odd choice for someone looking for companionship, they have long held a special place in Japanese stomachs, if not hearts.

Japan is one of the world's largest jellyfish consumers. Appetizers made of jellyfish strips steeped in vinegar and soy sauce are on the menus of most good Chinese restaurants here.

According to industry figures, nearly 359 tons of edible jellyfish were sold by Tokyo area wholesalers last year different species than those now being raised as pets.

Sadanobu Sugiura, of Pet Buyer magazine, said the popularity of jellyfish comes at a good time for sellers, who are slogging through a slump in the sales of home aquarium fish.

"Jellyfish still have the cachet of being something unusual, something that not everyone has yet," Sugiura said. "Calling them a status symbol might be too much, but it's something along those lines."

Some 50 to 60 pet shops in the Tokyo area now sell jellyfish, according to Hiroshi Yazaki, of Nisso Industry Co., Ltd, which has introduced special jellyfish aquariums costing between $461 and $508.

Without special tanks, the prognosis for domesticating a jelly isn't good.

Bubbles can penetrate jellyfish membranes, proving fatal. And because jellyfish float instead of swim care must be taken to keep them from sinking or getting sucked nto the tank's purification pump.

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