FACTBOX: Themes of Rio Carnival's samba group parades

(Reuters) - The highlight of Rio de Janeiro's annual Carnival celebrations are the two nights of parades by 12 samba groups, each featuring up to 6,000 dancers.

The parades start on Sunday night in the Sambadrome stadium. Each group presents an allegorical theme with a specially written samba song, costumes and giant floats.

Here are the main themes of this year's Carnival by each samba group, or school.

SAO CLEMENTE - One of several schools marking the 200th anniversary of the arrival of Portugal's royal family in Brazil.

PORTO DA PEDRA - 100 years of Japanese immigration to Latin America's largest country.

SALGUEIRO - Parade inspired by the beauty of Rio.

PORTELA - The origins and mystery of life.

MANGUEIRA - The group pays tribute to a fast-paced northeastern dance called Frevo, which requires acrobatic skills.

VIRADOURO - Shocking experiences. A planned float with a pile of model dead bodies commemorating the Holocaust was banned by a judge.