What kind of fish is best kept in a regular fish bowl without any filters?

Answer 1

If you want to keep fish I would strongly recommend buying a fish tank with a filter. I have noticed with only one fish they get lonely and just sit there as good as dead all day (of course this depends on what species of fish you keep!). They seem to be happier in groups if they're shoaling fish, such as Tetras. If you get more fish be sure you do not get a small tank, tanks under 10 US gallons are a waste of money.

Fish such as Comet Goldfish and such actually need tanks a minimum of 4ft long. They are often sold cheap, but this does not reflect the fact they get over 12" long and live over 20 years. They are also exceptionally messy fish really only best in ponds.

The humble Betta does not get scared by big tanks, but can be overwhelmed by power filters, they do well in softly filtered and heated tanks over 5 gallons, they should be very active and curious. Some Bettas seem to survive in unfiltered bowls but this does mean it's recommended by experienced fishkeepers and will not provide it with the stimulation and stability it really needs. Betta fish should have a small filter that is not very strong as they become iritated by the current taking them away because of there large fins. In the right care fish should live to their full life spans (for Bettas, that's over 3-5 years or more).

Another AnswerNo fish should be kept in a fish bowl.

No fish should be kept in captivity without a filter.

You must understand the reason for having a filter in an aquarium. Fish produce ammonia as waste, and it is toxic. The filter media has lots of surface area where beneficial bacteria can colonize on them to feed on ammonia. You must have a minimal 5 gallon tank even for a single betta fish. The tank must have a filter and it must be cycled before you add any fish, or the fish will die to ammonia poisoning which is one of the leading causes for fish deaths.