Rio de Janeiro is one of those great bird of paradise cities that gets into your bloodstream upon contact and, like Venice and New Orleans, won't let you go. Even honorary Cariocas (Rio natives) aren't immune to the sultry vibrations, the captivating music, the coming together of jungle, mountain, and curving white seashore. Satisfying a Rio craving 7,000 miles from the source is problematic, but Canto do Brasil, a stylish Brazilian restaurant in Hayes Valley, brings a little bit of the Tropic of Capricorn to foggy San Francisco every Friday and Saturday night. The tiny setting can barely contain the pure Rio energy of Samba Night, when the gorgeously festooned Aquarela and Samba do Coraçao dance troupes move their plumage to those irresistible rhythms and demonstrate the true meaning of Carnaval. Shows start at 8:15 p.m.; the bobé de camar‹o — prawns sautéed with yucca, peppers, and coconut milk — makes for a tasty overture.