When it comes to the single, solitary aquatic life, most people think of the goldfish in his little bowl.
But there is another type of fish that lives in even closer digs, and is arguably better suited to them: the Betta, also known as the Siamese fighting fish.
Pronounced "bett-AH", this exotically fringed fish hails from Southeast Asian swamps and backwaters, which are low in oxygen content. Instead of relying on its aquatic environment, the Betta utilizes an auxiliary breathing organ called a labyrinth that allows it to gulp air from the atmosphere.
As a result, a Betta's bowl doesn't need an aerator pump. Or, for that matter, a heater.
"If the room temperature is comfortable for you, it's comfortable for them," says Robert J. Goldstein, author of "Bettas: A Complete Pet Owner's Manual." "They're very rugged."
Bettas also are, he adds, relatively unflappable when it comes to their environment. "They're not a shy fish that is easily frightened or stressed." As for boredom, "they get a lot of stimulation just from their surroundings" - which includes human passersby.
Although many pet stores sell Bettas in small bowls that are about the size of an ambitious navel orange, some experts suggest a minimum of a half-gallon container.
If a Betta is kept in a container that small, however, the water should be changed once or twice a week to deal with ammonia buildup from the fish's waste. Be sure to treat tap water with aquarium dechlorinator, available at pet stores. And let it sit for a day or two to reach room temperature before using it to replace the water in your Betta bowl.
Bettas are beautifully colored fish, available in virtually every hue, sometimes with iridescence. Female Bettas are not as highly colored and have shorter fins than the males.
There's another reason why many Bettas live solitary lives in bowls on the living-room coffee table or atop the family computer desk: The males are highly territorial and cannot be kept together. When confronted with another male - or his own image in a mirror - the male Betta will display, flaring his fins and gill covers.
Trying the mirror trick too often is not only mean but counterproductive, Goldstein points out. "They can process information and remember things, and eventually, they figure it out and will ignore the mirror."
This aggressive tendency explains the Betta's colloquial name, the Siamese fighting fish. In its native land, the Betta has been fought for sport for centuries, although, Goldstein points out, a given fish will only be fought once, and the bout interrupted once the winner is made clear. While that means the macho Bettas are not permitted to fight to the death, some are so badly injured or weakened that they do not survive long anyway.
But its pugnacious leanings don't mean that a male Betta needs to be resigned to an Alcatraz-like existence. A male can be introduced into a community tank of similarly sized fish of different species, and can co- habitate with females of his kind - unless they rebuff his advances, at which point, Goldstein says, things can get "nasty." To prevent this, have multiple females to distract him and provide plenty of hiding spots as well as space.
While certain species of Betta are "mouthbrooders," and carry their eggs in their mouths, the species found in pet stores and most aquariums, B. splendens, is a bubble- nester. Making an egg repository at the surface of the water with mucous-covered bubbles that he blows, the male then lures the female under the nest and gets her to spawn, or release the eggs so he can fertilize them.