The fish market business is usually a simple routine of scaling, weighing and wrapping. But things got complicated for Steven Himelfarb Tuesday, when nine armed police officers surrounded his Kensington market, seized 40 of his biggest rockfish, took mug shots of the evidence and placed him under arrest.

"It was like a fish SWAT team right out of a grade B movie," said Himelfarb, 32, president of U.S. Fish Inc., which opened in Maryland five months ago. "The men were all armed, not with rods and reels, but with guns. You'd think we were the underwater mafia or something."

The Maryland Natural Resources Police charged him with 40 counts of illegally possessing oversized rockfish, or striped bass, the state fish of Maryland.

"They booked me in, of all places, Rockville," Himelfarb joked.

Capt. Franklin I. Wood, of the natural resources police, said Himelfarb's arrest was the result of a six-month undercover investigation. "We learned that he was selling illegal rockfish from Virginia and New York and we obtained a search warrant," Wood said.

State law prohibits rockfish longer than 32 inches from being sold or consumed in the state, no matter where it is caught. The maximum penalty on each count is $500 fine and three months in jail.

Wood said the iced evidence ranged between 37 inches and 52 inches and weighed between 22 pounds and 46 pounds.

The raid began at 6:35 a.m. when Himelfarb's brother, Stuart, 22, was unloading fish. Suddenly, beneath the delivery truck he saw the uniformed legs of police officers.

"One officer came around, showed me a search warrant and asked me if we had any rockfish," Stuart Himelfarb said. "When I said, 'Yes,' all of the officers ran around and into the market and began searching all over."

The officers measured and photographed the fish before flinging them into a passenger van. Wood said 38 of the fish went to the Maryland House of Correction in Jessup, where inmates will eat them later this week. The remaining two were placed on ice to await Hamilfarb's hearing July 9 in Montgomery County District Court in Gaithersburg.

"If we were making a movie, I guess you could call it 'Jail House Rock'," said Himelfarb, who was swamped with customers and phone calls yesterday. This included one man who said he was from Hollywood's Universal Studios, pleading for exclusive rights to Himelfarb's plight.

A beaming Himelfarb turned to his employes and said: "One day you're wrapping fish, the next day you're wrapping up a movie contract."

But his stardom was short-lived. When later efforts to locate his Hollywood caller failed, Himelfarb voiced what he suspected from the beginning: It was just another fish story.