"Nature is the artist," says Matthew McCann.

"All I do is select."

The 42-year-old koi farm manager and breeder is being unduly modest.

McCann has decades of experience with the blazingly colorful, boldly patterned mutant carp prized by landscape designers, hobbyists, and the serious enthusiasts who show competitively around the world.

"I like that [one] a lot," he says, singling out a two-year-old at Quality Koi Co. Inc.'s Nisei Koi Farm in Carneys Point, Salem County.

I see an energetic bunch of pretty fish splashing around in and attempting to leap out of a blue container that's rather like a kiddie pool.

But McCann sees living works of art.

Paintings in motion.

And he takes notice of the color depth, skin luster, and body shape of each.

An affable fellow who grew up in Manchester, England, McCann assesses the potential to grow - with koi, bigger is better - as well as the likelihood the fish will maintain its beauty into adulthood.

"Very, very few koi have a very, very high grade," he explains.

Assisted by apprentice Kyle Loveland, aquaculturist Briana Morgan, and hobbyist/volunteer Dave Hicks, McCann swiftly separates the fish to be put on sale from those that will spend another summer growing.

Koi can attain a length of three feet and live for decades.

"We produce about 10,000 babies a year," says Jennifer McCann, 39, who with her husband has run Quality Koi, since the Carneys Point facility opened in 2002.

The couple met through the koi business and are the parents of two young children. The family lives within walking distance of the 42-acre farm, which has 28 natural-bottom "mud" ponds.

The company is owned by Joseph Zuritsky, the chairman of the Parkway Corporation in Philadelphia. His interest in koi dates back nearly half a century; he began as a hobbyist and has become a respected expert.

"Our goal has been to produce top quality American-bred koi - direct descendants of the best bloodlines from the best breeders in Japan," Zuritsky tells me.

"It took us many years to get the genetics to produce jumbo fish that maintain their color and pattern," he adds. "It took a lot of trial and error."

And, as I learn during my visit to Quality Koi last Thursday, a lot of hard work.

"We're farmers, and just like field farmers, we can't get lazy," Jennifer says. "It's very labor-intensive."

The McCanns and their three employees care for about 5,000 koi in a complex that includes the outdoor ponds and nine greenhouses.

Those are where the koi spend their winters, dining on high-end food and swimming in pools of filtered freshwater.

No wonder two koi born and raised here went on to be named "grand champion" in competitions, Zuritsky notes.

"People from all over the country come in, buy a fish, and have us grow it for them," Jennifer McCann says.

A single koi can sell for thousands of dollars; one choice Quality Koi specimen went for $35,000 due to its "future potential to be a grand champion," she notes.

"But we're not koi snobs," she says, showing me around a greenhouse where consumers can buy directly.

"The majority of our market are people looking for a $25 fish that is pleasing to the eye. They're not going to go before a judge."

"We need to grow this hobby . . . not be snobs [and] turn people off," says Carmen Caputo, the president of the 42-member Tri-State Koi Club, which draws members from New Jersey, New York and Connecticut.

"Koi are captivating, and they're friendly," the 66-year-old Staten Island, N.Y., resident adds. "You can reach down and pet them."

"If you have them at home, they will interact with you," says Matthew McCann. "They will recognize your footsteps."

Who knew? Certainly not me, given the tragic fates of the goldfish my parents bought for us six kids at J.J. Newberry's in 1965.

Koi and their admirers inhabit a different world, where people often have deep knowledge of and devotion to the unusual creatures they have bred into existence.

"They're all my kids," says Matthew McCann.

"No two are the same," Jennifer McCann says. "Like snowflakes."

Caputo, a corporate account executive, explains the allure.

"I have a high-pressure job," he says. "It's nice to get home and sit by the pond, and watch them glide through the water with the red and the black and the yellow. . . . They're beautiful. Like living jewels."

856-779-3845 @inqkriordan