As for what kind of fish to raise, it has something to do with the industry you are engaged in (that's what Feng Shui says, but I haven't found the reason after looking up a lot of information). If you are engaged in some industries, such as running bath centers, nightclubs, hotels, speculating in futures, etc. You can raise vicious carnivorous fish such as golden dragons, silver dragons and maps. It's disgusting.
If you are engaged in legitimate industries, it is best to keep goldfish or tropical fish.