This was unexpected, but is just waiting for a commercial application. You have to watch the video to believe it, but this restaurant** in Japan has a goldfish tank…in the deep fryer.
Because oil floats on water, despite the massive heat (163 degrees Celsius) the goldfish simply stay away from the surface and all is well. They eat the crumbs of croquettes and other fried foods that fall to the bottom, and can live in there for 5-10 years** as they happily clean away, ignorant to the fact that certain death awaits any potential escapees.
This one is hidden away back in the kitchen where customers can’t even see it, but it could easily be made for display near the dining area for everyone to see. No word on whether they turn cannibal and devour their battered bretheren when they’re chucked in along with some potatoes.
Of course, some people like aquariums for ambiance, rather than deep-frying. I wouldn’t fry these though.
**Update** Just a little clarification on this. This fryer (from the WaterFryer company) is specially designed to allow the water inside without blowing up (sugei!). The location is not clear, however. As one commenter noted somewhere, it took the guy 10 years to create it. As for how long the fish can live in there, I was lazy in my translation and made a mistake. I suppose they could live in there anywhere from ten years to 10 seconds, depending on how foolish they are.