What happens to a goldfish if left in the dark too long?

that was very interesting.even low I had goldfish it is something I didn't know.and is worth noting for the future.

I didn't know that!

Exposure to sunlight into aquarium damages their eyes

This question made me think of Sheldon's glow-in-the-dark fish, and I wondered if I could buy one. Turns out, they are readily available in pet stores and Walmart, for around $10 each. They come in several tropical fish species and colors. I have two aquarium tanks in my home. I think pink glowing fish in a tank with dark gravel would look good.

I didn't know that

I didn’t even know that existed until now I just assumed 😢😱😧👎🏻

Oh! my gosh! That sounds awful to me right 🙁😔

So if I keep goldfish in a dark closet they'll turn into ghostfish. Got my new magic trick.