Think Wall Street trading is brutal? Head up to the grittiest part of the South Bronx, where cutthroat deals are made in the dead of night on a massive concrete floor that reeks of fish guts.

The New Fulton Fish Market is the nation's largest seafood market, and second in the world to Tokyo's. Here, in a refrigerated building the size of six football fields, fishmongers are frenetically filleting, selling and packaging seafood -- 200 million pounds a year worth close to $1 billion by some estimates. It is headed for restaurant tables, stores and mouths across America.

Glistening under the fluorescent lights is just about every sea creature. Most come in by truck, but about half are flown in from the ends of the Earth: Arctic char from Iceland; mahi-mahi from Ecuador; hamachi from Japan; branzino from Greece; salmon from Scotland; cockles from New Zealand.

Experienced buyers negotiate prices in seconds, judging quality on a look, a touch, a smell and often a raw taste.

"You know right away if fish is fresh. It's like looking into a woman's eyes -- you know what's there," says Roberto Nunez, a 44-year-old Peruvian immigrant who started out as a dishwasher and has been the buyer for more than a decade for celebrity restaurateurs Lidia Bastianich, her son, Joe Bastianich, and their partner, Mario Batali.

Five nights a week, Nunez shows up at 1 a.m. to purchase as much as $15,000 worth of seafood, enough to meet the demands of 10 restaurants. What's available on any given night depends on a variety of often unpredictable factors.

All night, dozens of men in coats and wool caps work to the soundtrack of mini-forklifts whizzing around, honking and spewing exhaust as they move seafood-laden pallets. The smell is a mixture of the fishy and the fresh scent of the ocean.

Nunez finally spots some striped bass. But when he lifts the gills, "it's no good; they're brown," he says dejectedly. (The gills should be bright red).

The hunt continues for the rest of his list: scallops, shrimp, squid, monkfish liver, fluke, shad roe, blowfish.

He spies black sea bass from New Jersey at $6.75 a pound. "How many do you have?" "One hundred pounds," says vendor John Dias.

"How about $5.50?" Nunez asks.

Dias relents.

Nunez later nabs red snapper from the Gulf of Mexico. He feels the fish, smells his fingers. It's fresh. OK, 60 pounds.

At another stall, he pops a raw Nantucket Bay scallop in his mouth, smiling. It's $20.50 a pound compared with a normal price of, say, $16. But these are extraordinary, and fresh -- "like a baby's bottom" to the touch.

Just before 3 a.m., a vendor whispers in Nunez's ear: Some striped bass might be on the way -- maybe.

He waits around for a while, and sure enough, a box lid opens to reveal eight bass from Delaware, weighing 121 pounds. Now, where to find at least 180 pounds more? He rushes off, scouring the cavernous market. And he gets lucky, landing 100 pounds.

At about 5 a.m., bartering slows as the sun peeks over the East River. As the city awakens and New Yorkers prepare for work, the exhausted fishmongers trickle out of the South Bronx facility to the surrounding Hunt's Point neighborhood of warehouses, truck depots, all-night bars and strip clubs. They will be back at night to do it all over again.

Get the latest news and more great videos at NewsdayTV Credit: Newsday

Remembering Challenger disaster 40 years later ... LI Works: Keeping ice rink nice ... Get the latest news and more great videos at NewsdayTV

Get the latest news and more great videos at NewsdayTV Credit: Newsday

Remembering Challenger disaster 40 years later ... LI Works: Keeping ice rink nice ... Get the latest news and more great videos at NewsdayTV

SUBSCRIBE

Unlimited Digital AccessOnly 25¢for 6 months

ACT NOWSALE ENDS SOON | CANCEL ANYTIME