Their uncanny charm suggests divine direction from Poseidon himself. Only a god with a gift for costume design and character development could squeeze so many hugely cute and charismatic qualities – a chameleon-like craft for camouflage, a monkey’s prehensile tail, a kangaroo’s marsupial pouch, a horse’s noble jaw – in one tiny fish. Their names are similarly heaven-sent: zebrasnout and potbelly, dwarf and shrimpfish, weedy and leafy sea dragon among them.

But according to Monterey Bay Aquarium Senior Exhibition Develop Ava Ferguson, it’s neither their celestial charisma nor dashing names that gets humans most silly-happy about seahorses, 15 species of which will enchant and entertain as part of The Secret Lives of Seahorses special exhibit that opens at the Aquarium Monday, April 6. It’s their famously unconventional courtship.

“THEY’RE THE ONLY ANIMALS WHERE THE MALE GETS PREGNANT AND GIVES BIRTH.”

Many fish release eggs haphazardly into the ocean. Instead, seahorses release their dance moves (and, with a reproductive organ called an ovipositor, deposit their eggs in the belly of the male, where they are fertilized).

“They purposely pick their mate,” Ferguson says. “In general, the female approaches the male on a daily basis and they dance. In the first few days she’ll deposit the eggs, then checks to see if he’s pregnant.”

Depending on the species and individual, the pairs rendezvous for days or weeks thereafter to intertwine tails and waltz around.

The male seahorses and their parental care are in high demand.

“They’re the only animals in the animal kingdom where the male gets pregnant and gives birth,” Ferguson says. “After the male gives birth, she visits the next morning, eager to give him more eggs throughout the breeding season. Once they’re not pregnant, they get pregnant again. Real fast.”

This love story anchors the “Getting Together” gallery, one of three that structure the $3 million, 5,000-square-foot temporary exhibit, which fills the space where Jellies, Living Art set up shop for six-plus years (Aquarium spokesfolks say the seahorses’ stay will run until Sept. 4, 2012).

In “Getting Together,” on a specially designed, tall rectangle of a television monitor, an arresting scene spills forth in bright blues and yellows: Intricate newborn dwarf seahorses pop from papa like slippery, popping popcorn. Catching such small-scale scenes in such a big and breathtaking way wasn’t easy – it demanded both technology and time. The lens used to capture the tiny babies – which Ferguson says are the size of a grain of rice – is thousands of times their size; timing the birth, she adds, meant “[cameraman] Chuck Saltzman was waiting for hours.”

Aquarium Associate Curator Jonelle Verdugo knows the feeling. She’s been eagerly anticipating the gestation of this breakthrough exhibit since a small and fleeting temporary display wowed so dramatically that managers were convinced they had to saddle up the seahorses again.

“After the 2001 exhibit closed, it was so popular that the Aquarium knew they wanted to do a larger exhibit,” she says, standing in the backstage labyrinth of aqua-blue tanks filled with all sorts of bizarre-but-beautiful seahorses. “We’ve been getting ready for this since ’06. To see it here now, after all those years, is very nice.”

Before visitors get to the baby-making, they have to meet the family. In “Seahorses and Kin,” that means viewing a diverse sample of the shapes and sizes aquatic equine take.

There are dragon pipefish, long and narrow like eels, but with the signature fused jawbones of seahorses and one of the strongest prehensile tails in the sea; pale brown, yellow and white zebrasnout seahorses and their gorgeously striped aardvark-esque mouths; and ribbon pipehorses, with appendages ingeniously crafted by evolution to look stunningly similar to seaweed.

More spot-on disguises await in the next gallery, “Growing Up.” Distant seahorse cousins called shrimpfish wear dark black stripes that make them look like sea urchin spines when they tuck themselves, heads down, into protective urchin armaments. Lined seahorses vary their colorings from black, brown or gray to yellow, red and orange depending on their surroundings. (Another impressive note from their resumé: The papas can pop out up to 300 young in one batch).

The leafy and weedy sea dragons sport appendage-dripping costumes befitting their names – in green, yellow and purplish tones – which are elaborate enough to render Liberace’s frilly fashion sense tame.

Four more species make their appearances in “Getting Together” – ranging in scale from the adorable dwarf seahorses (less than an inch tops) to big water ponies like the 10-to-12-inch potbelly seahorses and the up-to-a-foot-long Pacific seahorses, California’s only marine steeds.

Fortunately, their fascinating facets allow seahorses of all sizes to take on another role beyond romantic dance machines of the deep or chameleons of the coral bed: statesmen.

“Seahorses are wonderful ambassadors for ocean conservation because they live in the most endangered habitats in the world,” Ferguson says. “When you save a seahorse, you also save some of Earth’s most precious marine habitats.”

Unsurprisingly, the powers that be at the Aquarium are using the exhibit to leverage as much conservation as possible. A digital kiosk will provide the opportunity to send Gov. Arnold Schwarzenegger an electronic postcard supporting the creation of marine protected areas in the Pacific seahorse’s native SoCal seas. Visitors can also pick up educational cards that address the troublesome dried seahorse curio trade. Meanwhile, Verdugo adds, breeding seahorses and observing them over time will go a long way towards demystifying the little guys’ needs and habits.

“So little is known about seahorses that we are at risk of losing these animals before we even know them,” Ferguson says. “Until recently, we had no idea that seahorses were being caught and collected at a rate that threatens their survival.”

There’s something godly in the effort to reverse that. Poseidon would be pleased.

THE SECRET LIVES OF SEAHORSES is included with regular aquarium admission beginning April 6 ($29.95/adult; $27.95/senior and student; $17.95/child 3-12, disabled; free/children under 3). Monterey Bay Aquarium, 886 Cannery Row, Monterey. (831) 648-4800, www.montereybayaquarium.org