'Megafish' explorers seek giant stingrays

Catching a ray can be dangerous, he says, especially before its tail has been neutralized. "Crocodile Hunter" Steve Irwin was killed by a stingray barb in 2006, and a Florida man was critically injured that same year when struck in the chest by a ray's barb.

Wuttichai Kuachareonsri, a member of Humphreys' crew, stopped fishing for a year after he was stung in the leg by a ray barb. "I never have felt pain like that," he says. "It really frightened me."

On his fishing trip with Hogan, Humphreys boasts about "monsters" below the tranquil river and insists it is a matter of time before his team lands a world record ray.

The anglers head to the Ban Pakong and Maeklong rivers just two hours outside Bangkok, winding their way past office towers, Buddhist temples and busy highways. Fish farming pens dot the riverbanks and sounds of construction and puttering boats echo across the water.

Both spots have given up rays in the past. But on the their first day on the Ban Pakong, the fishermen come up empty. Humphreys blames the heavy rains that have swollen the river.

The next day, they have better luck on the Maeklong.

The rod bends almost into the water, and Wirat struggles for almost a half hour as the ray dives under the boat and across the bow.

It finally is brought to the surface, revealing its big bulging eyes and dark, coarse skin. Its tail alone is 12 feet long.

Hogan says catching such a big ray so close to a big city is a sign the species is thriving despite pollution. He is awaiting government permission to launch a two-year study to catch and tag 20 or 30 more rays to better understand their movements.

With that data, Hogan is hoping to do what he has done for the Mekong giant catfish, once almost fished to extinction. Hogan's work helped establish its endangered status and prompted authorities in Laos and Thailand to limit total catches to four a year.

WWF freshwater biologist Chavalit Vidthayanon, who discovered a smaller ray species in Thailand four years ago, agreed more research was needed to better understand the health of the big fish.

"We need to know its exact population and habitat so we can work on conservation and find ways to better protect them," he said.

For the easygoing Hogan, the research could help end what has become an epic journey to find "the king of the river."

"We're getting close to the record and I'm very confident that a fish of record size existed," he says. "The question is whether it still exists."

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