It’s a kinder, gentler, more politically correct animal world out there. Rabbits are no longer relegated to outdoor hutches. Dogs aren’t chained to dog houses.

And goldfish don’t belong in fishbowls.

“A bowl really isn’t a viable container for a goldfish,” says Russell Taylor of Vienna, Va., a longtime goldfish keeper and member of the board of the Goldfish Society of America (www.goldfishsociety.org).

As iconic as the bowl-ensconced little yellow fishy might be, it’s problematic on many fronts, not the least of which is elbow room.

“A goldfish has the potential to grow into a fairly large fish,” getting 6 to 8 inches long in a year, Taylor says. Bowl-dwelling stunts a fish’s growth, along with its longevity — a year or two compared with seven to 10 years in optimal conditions.

Taylor notes that the ever- expanding goldfish needs a good-size aquarium. He recommends allotting 10 gallons for every fish.

Then there’s housekeeping. “Goldfish put out a lot of waste products, such as ammonia, that are very toxic to them,” he says. A filter system (preferably with a flow rate of 10 times the tank volume per hour) and frequent water changes (at a minimum, 50 percent a week) are musts in the hygiene department. And a fishbowl just isn’t large enough to support enough “good” bacteria to convert waste into less toxic compounds.

Raised by fishkeepers in China since before A.D. 1000, goldfish have “double the amount of genetic material and chromosomes that most fish have,” Taylor says.

That explains the species’ many mutations, the most basic of which is the gold color; other hues include black, blue, calico and albino (really the absence of color, it’s accompanied by pink eyes). Among the 20 or so categories of goldfish mutations are eye types, such as celestial eye, which protrudes and looks upward; fin mutations, such as double tail fins; and body shapes, such as the round body.

Price ranges can be just as dramatic. “There’s a pretty remarkable spectrum — you can pay 10 cents in a pet store or several hundred dollars from a breeder who specializes in fairly high-end fish,” says Taylor, who’s never spent more than $30. “And the people who keep them sort out in demographics that correspond to those prices.”

Still, even fancy varieties are available at pet stores for a few dollars. But that affordability actually may work against the goldfish.

“If you buy a sufficiently large tank, filter and other necessary equipment, you’re going to invest at least $50 for a fish that might cost 50 cents,” Taylor says. Given those lopsided economics, “it’s hard to push people in the right direction.”