SAN DIEGO -- Looking thin and unshaven, the reputed leader of the Arellano-Felix drug cartel pleaded not guilty Thursday to racketeering, money laundering and drug charges in his first appearance in a San Diego courtroom.

Francisco Javier Arellano-Felix, 37, was captured Monday by federal drug agents and the Coast Guard while deep-sea fishing off Cabo San Lucas, in Baja California.

Two suspected assassins were also among the eight adults and three juveniles apprehended aboard the fishing boat Dock Holiday, authorities said.

A son and nephew of Arellano-Felix were among the three children on board the fishing boat, and will be returned to their families, said U.S. Attorney Carol Lam.

Arellano-Felix and the other adults aboard the boat arrived in San Diego Thursday morning.

Amid heavy security, Arellano-Felix nodded his head as the clerk for Magistrate Leo Papas informed him of the charges included in a 2003 superseding indictment.

Arellano-Felix was clad in an orange shirt, plaid shorts, handcuffs and leg irons.

Assistant U.S. Attorney Laura Duffy told the judge that the government wanted the youngest of the four Arellano-Felix brothers held without bail because he was a flight risk and danger to the community.

Papas scheduled a detention hearing for Monday before U.S. District Judge Larry Burns. A motions and trial-setting hearing was scheduled for Oct. 2.

The other men detained on the fishing boat appeared in court separate from Arellano-Felix.

The judge told them they were being held as material witnesses. They will also have their detention hearings on Monday.

Authorities believe the arrest of Arellano-Felix "signals the end of two decades of the most dubious, powerful and violent drug trafficking organizations," said John S. Fernandes, special agent in charge for the Drug Enforcement Administration office in San Diego.

Mexico's Deputy Attorney General, Jose Luis Santiago Vasconcelos, said the arrest of Arellano-Felix in international waters south of Cabo San Lucas was made possible through cooperation between the U.S. and Mexican governments.

"Today we close one more chapter in the war against drugs," said Vasconcelos.

He said the arrest "totally devastated the Tijuana drug cartel."

Arellano-Felix, known as "El Tigrillo" or "little tiger," and 11 other alleged high-ranking members of the Mexican cartel were indicted in federal court in San Diego in July 2003 on charges of importing and distributing drugs into the United States.

Javier Arellano-Felix and his brothers, Benjamin and Eduardo, were charged in December 2003 with conducting an illegal enterprise through a pattern of racketeering activity, conspiring to import and distribute cocaine and marijuana, and money laundering.

A fourth brother, Ramon Arellano-Felix, considered the cartel's enforcer, was killed in a shootout with police in 2002. Benjamin Arellano-Felix was arrested a few weeks later.

Eduardo Arellano-Felix is still at large, authorities said.

Authorities said Francisco Javier Arellano-Felix took over the cartel in 2002. The Arellano-Felix family has controlled the Mexican drug trade since the late 1980s, authorities said.

The indictment also alleges that the Arellano-Felix Organization negotiated with Columbian cocaine traffickers to buy tons of cocaine, and then arranged to have it smuggled into the United States.

It also claims the Arellano-Felix Organization recruited bodyguards and assassins who killed rival drug traffickers, informants and Mexican law enforcement and military personnel, as well as members of the news media.

The indictment accuses the Arellano-Felix organization of carrying out 20 murders in the United States and Mexico.

The Arellano-Felix cartel is also believed to have been responsible for a sophisticated smuggling tunnel discovered between Tijuana and an Otay Mesa warehouse in January.

If convicted, Javier Arellano-Felix faces up to life in prison and forfeiture of almost $300 million.