Correction: An earlier version of this article incorrectly described participants as using crossbows. Compound and recurve bows were used; fishing with a crossbow is illegal in Maryland. The article also incorrectly said that female snakeheads carry an average of 400 eggs, and that the highest number recorded in a fish by the U.S. Fish and Wildlife Service was 1,000. They carry an average of 40,000, and the record fish carried 100,000. This version has been corrected.

With his friends shouting “Snakehead!” and “That sucker is huge!” and “You’d better not miss!” Brian Stack crouched in a 20-foot boat, drew back the string of his bow and took aim at the biggest fish they saw all night.

Even when his arrowlike bolt ripped into its back, just below the head, they kept shouting. “Don’t lose him, don’t lose him!” As Stack pulled the snakehead in by an attached rope, they kept yelling. “In the net! In the net!”

“We were hootin’ and hollerin’, ” Stack said. “We saw how big he really was when he started fighting.”

That snakehead — with fins like a catfish and flesh like a Burmese python — weighed in at more than 16 pounds, the largest caught during the two-day Potomac Snakehead Tournament that ended Sunday at Smallwood State Park on Mattawoman Creek in Marbury, in Charles County. Stack and five buddies — Teamblazer Bowfishing — caught 25 fish in all, nearly 230 pounds, earning them a $1,500 first prize for total weight and $975 for the largest fish.

Seein’ Red Outdoors, a team of youngsters from La Plata and Cobb Island, none older than 16, took second prize — $585 — for catching 33 snakeheads totaling 180 pounds.

The contest, in its second year, removed more than half a ton of invasive northern snakeheads from the Potomac and its tributaries, 1,402 pounds, nearly doubling the goal of its chief organizer, Austin Murphy of Whackfactor Outdoors, a hunting group. Since 2002, when snakeheads were discovered in a Crofton pond, and 2004, when they were found in Potomac tributaries, biologists have worried that this top-level Asian predator would lead to the demise of native fish.

“We’re looking to double last year’s 435 pounds,” Murphy said before Sunday’s weigh-in.

The number of participants in the tournament also doubled this year, to 110 people on 18 teams.

The freewheeling competition had a few stiff rules, such as the one reinforced by an announcer at weigh-in: “Just a little reminder for the teams, all fish must be dead.” Maryland advises anglers to kill the nuisance fish as soon as they catch them.

The point of the competition was to remove as many snakeheads as possible from the watershed.

But there was more. “We’re not only removing fish from the ecosystem, we’re organizing a snakehead dinner with celebrity chefs,” Murphy said. Cooking started at 1 p.m., and about 75 diners lined up to taste the snakehead ceviche and burgers.

The ceviche was plated on blue corn chips, garnished with vegetables, gourmet style, like on the Food Network show “Iron Chef America.” The ceviche was tart and sweet, melting on the tongue. The burger was brownish yellow outside like a crab cake and smooth and flaky white inside.

Chad Wells, the chef from Alewife in Baltimore who made the ceviche, said some people shy away from eating snakehead because of the name. His mother, for instance. “I just gave it to her without telling her what it was,” he said, and she loved it.

“They fry, grill, sautee, bake, steam — they’re great,” Wells said.

John Rorapaugh of ProFish, a District-based seafood supplier, hoped contestants would donate snakeheads for a cooking competition to be held this summer at Tony and Joe’s restaurant on the Georgetown waterfront.

Maryland Department of Natural Resources officials hope to cultivate a taste for the fish among state residents, creating a demand that would help reduce the growing snakehead population.

Excellent parents

Female snakeheads are thought to carry an average of 40,000 eggs. But four days ago, Josh Newhard, a fish biologist at the U.S. Fish and Wildlife Service, found one with 100,000 eggs after electrifying the water to test stunned fish. “That was the most we’ve ever recorded,” he said. “It means removing these females could potentially have an impact.”

Snakeheads are excellent parents. Males and females shepherd their young, which travel in ball-shaped schools, to protect them from predators, ensuring a survival rate higher than that of native fish, Newhard said. The fish are an apex predator at the top of the food chain: Almost nothing preys on them, while they eat almost everything.

“They compete for the same food source with largemouth bass, white perch, yellow perch” and other fish, said Steve Vilnit, director of fisheries marketing for the DNR.

A possible record 18-pound snakehead was caught in Virginia’s Occoquan River last month.

Cecil Gilroy of Teamblazer Bowfishing said he could tell “the population is exploding. Two years ago, we only saw one or two at night. Last night we shot 25 and missed 15.”

No time to sleep

During the tournament, fishing mostly happened at night, with boats hugging the shoreline where snakehead swim among underwater grasses. Teamblazer Bowfishing launched about 6 p.m. Saturday and returned at noon the next day for the 1 p.m. weigh-in. Stack spotted the prize-winning 16-pounder under halogen lights shining from the boat about 1 a.m.

“We didn’t have time to sleep,” said Frank Gore of Port Tobacco, another team member. There was time for that after counting their winnings.

Favorite fishing areas are kept secret from other teams. Michael Nutter, 15, wouldn’t reveal where he and three buddies from La Plata High School — Nick Hill, 15, Cole Bowling, 14, and Nick Shymansky, 16 — caught their 33 snakeheads.

“It’s shallow, and they spawn at this time of year, and the water is real clear,” Nutter said.

About 10 p.m., Shymansky saw a huge fish, 14 pounds. He aimed the bow just below where the fish seemed to be, since the water creates an illusion. His bolt ripped a hole in the fish’s back.

The teenagers were shouting so much that Shymansky eventually lost his voice.

How the tourney began

The idea for the tournament started on a warm night last July. Austin Murphy was on the Mattawoman with three buddies fishing for snakeheads, as they do three nights a week in summer. (They tell their significant others they’ll return at 1 a.m. but actually get in at daybreak.)

In the black night, with frogs croaking, muskrats digging at the shore, osprey swooping for fish and bugs darting around their heads, Murphy started talking as he nursed a Flying Dog beer. “We can have a big giant tournament doing this,” he said.

“Austin’s a dreamer, he thinks big,” said Jesse Swann, one of his partners at Whackfactor Outdoors. “Sometimes he has ideas and you hope he forgets about them. But this time we were all on board.”

In five weeks, they put together the first tournament, held on Labor Day, Murphy said. “We were hustling.”

The DNR, the federal Fish and Wildlife Service and 14 sponsors, including Ben Savage, vice president for marketing and brand development at Flying Dog Brewery, liked Whackfactor’s pitch.

“We really liked the idea of hunting fish in the spirit of conservation,” said Savage, who donated a beer to everyone who attended Sunday’s event.