Actually fancy goldfish and bowls go back centuries with Chinese selectively breeding and striving for a fancy goldfish which looks good from above and doesnt need to swim as much as its wild ancestors. Some of the most skilled fish keepers I know are able to keep fish without filtration for years healthily.
Glass bowls and inappropriate use of comets/shibumkins is a much more recent thing.
Glass bowls and inappropriate use of comets/shibumkins is a much more recent thing.