Jose Cuervo, a brand of Diageo, launched Jose Cuervo Authentic Light Margarita. The ready-to-serve cocktail combines Jose Cuervo Especial Gold tequila, Triple Sec and a twist of lime. The variety contains fewer than 100 calories in each serving, the company says. The brand also plans to introduce Jose Cuervo Authentic Watermelon Margarita, which combines the classic lime flavor of a Margarita with watermelon. Jose Cuervo Authentic Light Margarita and Jose Cuervo Authentic Watermelon Margarita contain 9.95 percent alcohol by volume and are packaged in 750-ml. lightweight PET bottles for $8.99 and 1.75-liter bottles for $14.99. The brand also announced the May launch of Zero Calorie Margarita Mix.Diageo, Norwalk, Conn.