LAKE MOULTRIE -- The fat blue catfish weighed nearly 140 pounds. If the fish weren't sluggish with the cold, the fight could have snapped the line or straightened the hook. Or the angler simply might not have been able to haul it in.

But earlier this month, commercial angler Leland Selph of Cross landed the largest blue catfish ever caught in Lake Moultrie -- a monster nearly 5 feet long. The only reason it's not a state record is the state doesn't maintain records for fish caught on trotlines, or strings of hooks strung like clothespins on lines under the water.

The 136-pound, 6-ounce fish would have smashed a 21-year-old record by nearly 30 pounds. The record fish is 109 pounds, 4 ounces.

Selph couldn't be reached for comment, but he told state Department of Natural Resources biologists he cut some 35 to 40 pounds of fillets from the fish. It was so girthy the scale at Black's Fish Camp couldn't weigh it, said Wayne Weiss, of Cross, a friend of Selph's. The fisherman fought for 45 minutes to get the blue in the boat.

"He said it was all he could do to hold on to it," Weiss said.

The real wow factor? There's very likely more big catches out there.

Selph usually runs about 2,000 hooks per trotline, and it's not unusual for something big to bend 25 of those hooks straight before the line comes in, said Weiss, who occasionally goes out with Selph. "They complain there's no big fish in the lake. But I'm sure there's several more like this one," he said.

"It does give us an idea of what's been running lines off the reels for years," said DNR biologist Scott Lamprecht. Nearly a half-century after the fish first were stocked, state biologists have never seen anything that big, but the only reason might be that people haven't been using strong-enough gear.

"I expect people will gear up (now) and be able to land them. There's some whoppers out there, and I wouldn't be surprised to see the record smashed by about 20 pounds," he said.

The state record catfish, caught on a rod and reel, was taken by the late George Lijewski, of Summerville, in the Tail Race Canal in 1991.

The newest catch is a bolt out of the blue for the beleaguered angling businesses along the Marion-Moultrie lakes, which tourism officials say are worth some $300 million per year in tourist dollars. The blue catfish, introduced in 1965, came into its own as a catch after the 1992 record, and has become a go-to species for trophy anglers.

The claim-to-fame catch, the striped bass, mysteriously began declining a decade ago, hurting the businesses. Years of drought that dried up acres of the lake and stranded boat landings exacerbated the difficulties. Restocking and stricter catch limits appear to be restoring the stripers.

Reach Bo Petersen at 937-5744 or follow him on Twitter at @bopete.