Betta fish (Betta splendens) are a popular and inexpensive pet. Suitable housing is a container with a volume of as little as one cup of water. Bettas come in many exciting colors ranging from pale yellow to iridescent black. Also known as fighting fish, this pet is best kept singly. They are a couple of inches long, with flowing fins, some of which double their size. Easily riled, these fish flap their gill covers at you when you so much as look at them.
Talk about low maintenance, this fish does better in dirty water. Betta fishes are able to get oxygen by swallowing air, thanks to a unique organ in their head called a labyrinth. There is more oxygen in air than water, especially dirty water. In the wild, these fishes live in swampy areas so they habitually swallow air to survive. So for them dirty water is more like home. That's great news for folks who want a pet of minimum fuss.
Pet shop personnel advise that when keeping fish in a bowl it is best to replace only one third of the water at a time, when cleaning. With the Betta it is best to do this infrequently .
The male Bettas are the fighters. When you go into a pet shop you usually see the males on display. They are often lined up on a shelf in their individual containers. They react to the male beside them with manly movements of their unpaired fins. They fix their opponent with a menacing stare as they undulate. If the fishes were in the same water together they would bite to the death. (Meanwhile, safely tucked in the back room, the females await the victor and the mating that will follow.)
Keeping one of these fearsome fellows in the home is easy and offers interactive drama. Put one on the dining table as a centerpiece. As you pass the potatoes he will flail his fans at you. Put one beside the sink in the bathroom and he'll watch you wash your face with hostile interest. Put one on the coffee table and every time you reach for the remote he'll lunge ferociously.