tilthat:

TIL the use of bowls to house goldfish comes from a misunderstanding of Chinese display vessels–small, temporary containers to show guests goldfish that were otherwise housed in ponds. Fishbowls are so detrimental to goldfish health that they are prohibited by places like Rome for animal cruelty.

via http://ift.tt/2gYipzR

This is absolutely correct!

The people who originally domesticated goldfish would keep them in ponds, and when they wanted to show them off to guests, they’d put a couple of them in a big glass bowl full of water and set the bowl in the middle of a table. The goldfish would spend, at most, an afternoon in the bowl, then would be put back into the pond. Perfectly healthy for the fish, and probably good enrichment to watch everybody outside the bowl.