Cardboard Cutouts Cure Lonely Aquarium Sunfish’s Depression

  • Who knew a fish could love the celebrity lifestyle this much?

Many animals do not fare particularly well in captive settings, like zoos or aquariums. The enclosed spaces, lack of activity, and hordes of hairless apes coming to gawk at them can quickly start wearing on their nerves.

And then there’s this ocean sunfish who loved it all so much that it got depressed when its fans suddenly disappeared.


The sunfish, or mola, arrived at a Japanese aquarium in early 2024. The fish seemed to thrive in its tank, eating heartily and growing larger than it already was.

However, after a few months, the aquarium closed for lengthy renovations. Left on its own, the fish soon stopped eating and began to exhibit bizarre behavior.

The aquarium staff naturally thought the fish was sick. Perhaps it had digestive issues, suffered parasites, was disturbed by the construction noise, or perhaps all three.

Despite various ate making the sunfish feel better, its condition continued to decline. Finally, a staff member voiced a thought — the fish had always seemed to enjoy an audience, so maybe it was lonely.

It seemed crazy, but nothing else had worked, so the aquarium staff decided to act on the idea. They began visiting the sunfish more, and they also arranged what are essential cardboard cutouts around the tank to give the fish the illusion of a crowd.

And what do you know? As soon as its “friends” returned, the fish bounced right back and began eating again.

Thriving in a New Home

Our sunfish was caught off the coast of the Kochi Prefecture in southern Japan. Weighing 61 pounds and measuring more than two and a half feet in length, it’s a real featherweight for a sunfish, which can be more than 15 feet long and weigh upward of 6,000 pounds.

Yet, its smaller size made the fish a good candidate for an aquarium specimen. The sunfish was taken to the Kaikyokan Aquarium in the southwestern city of Shimonoseki.

The fish is a bit of a mystery, as the aquarium staff hasn’t been able to figure out if it’s male or female, and hasn’t even named it. Still, the sunfish became a big hit at the aquarium.

“The sunfish was popular before the renovations. It’s curious and would swim up to visitors when they approached the tank,” Kaikyokan employee Mai Kato told Mainichi Shimbun.

As a true testament to how well the sunfish was doing at the aquarium, it kept chowing down on jellyfish (its favorite food) in such amounts that it has grown larger while living in the aquarium.

Lost Appetite

It was all going well — and then came December 1, 2024. The Kaikyokan closed its doors to the public for a six-month-long renovation project.

That’s when the sunfish’s problems began. All of a sudden, the fish started suffering from baffling health issues.

To begin with, it stopped eating. No matter how many jellyfish the staff dumped in its tank, it wouldn’t touch them.

Additionally, the sunfish’s behavior got a bit… Loopy. It started scraping its body against its acrylic tank for an unknown reason.

Of course, the aquarium staff figured the fish was sick. They suspected the fish may have some digestive issues, potentially caused or exacerbated by the loud noises and vibrations emanating from the renovation work.

They attempted to make the fish feel better in various ways, for instance by giving it less food and visiting the tank while construction work was happening. However, nothing seemed to help.

Together Again (Kind Of)

Having seemingly tried everything, the aquarium staff had a meeting to come up with additional solutions. At the meeting, somebody asked an odd question.

What if the fish was lonely and depressed?

It seemed like a ridiculous suggestion. But it’s not like doing something based on the idea could do any further harm, so the staff staged an experiment.

They brought out a bunch of unused staff uniforms and hung them on the outside of the tank. To further sell the illusion of a crowd, they also printed out some facial photos and taped them on top of each uniform shirt.

Basically, they surrounded the sunfish’s tank with cardboard cutouts.

We can imagine the staff probably felt a little ridiculous while doing this. It was all justified the very next day, however, when the fish began happily munching on jellyfish again.

Now, the sunfish has bounced back to being its energetic self. Turns out, it had grown so accustomed to being a celebrity that its life felt empty without an audience.

“I’m glad it’s doing better. It must have been lonely because it’s so friendly,” Kato mused.

The Kaikyokan is scheduled to open again in the summer. Its staff isn’t sure how long the cardboard cutouts will fool the fish, so they hope visitors come again to see their favorite mola.

It sure is looking forward to reuniting with its friends.