One look at their drifting dance is often enough to send visitors into a reverential reverie.

“People come to MBA, see the jellies and are hypnotized,” says Chad Widmer, Monterey Bay Aquarium senior aquarist. “They stop, look at them, mesmerized, and the wheels start turning: ‘I wonder if I can have that in my house?’”

A rather famous rapper wasn’t immune to their allure.

The rapper– a celebrated dancer himself– decided he wanted the jellyfish man to design a tank for his place. But that didn’t float for Widmer– who classily hesitates to say exactly which rapper (hint: the Grammy Award-winning artist’s name rhymes with Gusher)– and not just because he didn’t want to see it flaunted on MTV’s Cribs.

“I don’t pander to the rich,” he says over a draft beer at Aquarium’s Portola Restaurant. “I’m a man for and of the people. Wealthy people wanted them, but I’d much rather make them accessible to Bud and Ethel.”

With a new book, Widmer has done precisely that. How to Keep Jellyfish in Aquariums: An introductory guide for maintaining healthy jellies seeks to democratize the art form he has perfected while helping cultivate the Outer Bay jellies exhibit, the most popular special exhibit in Aquarium history.

“I wanted to make this for anyone,” he says. As he writes, “The scientific literature contains clues about jellyfish husbandry, but the language can be cryptic for the uninitiated… [T]he purpose of this guide is to present in plain language some proven methods.”

The resourcefulness he gained early on, building things out of little more than purpose and pragmatism, should serve readers well.

“Growing up, my parents didn’t buy many things. I had to make it for cheap.” So little Widmer fashioned everything from zip-lines to soap box derby cars out of whatever he could get his hands on. “Igloo coolers make great boats,” he says.

To that end, he has developed a penny-budget “trickle filter,” a wet-dry contraption that water-purifying bacteria can live on. “You can buy the nice acrylic box filter for $150 or $200,” he says, “or realize what’s going on, grab a recycled jug, cut off the bottom, use plastic army men, or dinosaurs, whatever, run the water through and it does the exact same job for $2. I show step by step how to build a filter like that in the book.”

Fittingly, the book itself came from a practical place. “Visitors, three or four times a week, would ask me questions,” Widmer says. “‘Can I keep jellyfish in my living room?’ Same with jellyfish aquarists– there’s over 50 in America, 20 internationally– always coming to you, always asking the same questions: ‘How do I adjust the current? What’s best for display? How do I feed them?’

“I thought, ‘I should write a book instead of answering the same questions. I gotta write it, or someone else will.’”

In the country’s hobbyists, he sees the potential for some serious invertebrate inertia: “There are 14.5 million people in America with a fish tank of some kind.”

The scientist buying up all the Army men at the thrift store is an Army man himself. In fact, his experience as an M1 tank driver was vital to him launching his career and, less directly, to naming a jellyfish after Henry Rollins.

As he says in the intro, “[I]t should be known that I very much appreciate the U.S. Army college fund and Humboldt State University for the education that allowed me to do this work.”

Widmer learned that Rollins had worked the USO tour while taking in a spoken-word show by the former hardcore punk artist at Henry Miller Library. Widmer sent a note of thanks and the two exchanged e-mails.

“If you’re a soldier and get a chance to forget where you are– or remember things are normal somewhere– that’s a powerful thing,” Widmer says. “Rollins does that with the USO tour, to remind troops, ‘Things are normal, we haven’t forgotten you.’”

When Widmer discovered a heretofore-unknown jelly while plying the depths of Monterey Bay around two years ago, he hadn’t forgotten Rollins’ contribution. The 3-milimeter organism, the first member of its genus to be found in the submarine canyon, was named Amphinema rollinsi.

It’s an interesting version of normal: The kind a revolution-bent hard rocker can give soldiers like the one who became a Harley-riding jelly lover. Of course, Widmer’s after his own kind of not-so-normal normal himself.

“One day, you will be able to easily go to the pet store and see some moon jellies as easy as a guppy, and get everything you need,” he says. “Anywhere there is a normal fish tank– doctors’ offices, dentists, homes– there can be a jellyfish tank.”

Of course, that would include a certain rap star’s lavish pad.

How to Keep Jellyfish in Aquariums (Wheatmark, $29.95) is available now at http://www.amazon.com and will be soon at the Monterey Bay Aquarium gift shop.