A Japanese man has pleaded guilty to federal charges of illegally smuggling 55 live turtles and tortoises into the United States, the US Department of Justice has said in a statement.Atsushi Yamagami was arrested in January for allegedly helping smuggle in a shipment of 55 live turtles and tortoises that were concealed in snack food boxes in a suitcase at Los Angeles International Airport.The 39-year-old pleaded guilty to one felony count of smuggling on Monday and is scheduled to be sentenced on October 31. Yamagami faces a maximum penalty of 20 years in federal prison.A second Japanese citizen, Norihide Ushirozako, was arrested during the same smuggling operation and pleaded guilty in May. Ushirozako is scheduled to be sentenced Tuesday. The charges against Yamagami and Ushirozako are the result of a US Fish and Wildlife undercover investigation deemed \"Operation Flying Turtle.\"In July 2010, undercover agents infiltrated the smuggling ring and purchased approximately 10 protected turtles and tortoises from a person linked to Yamagami, the US Department of Justice said.The reptiles were all protected by the Convention on International Trade in Endangered Species (CITES).