Cabral-Solís, Esther, CRIP-Manzanillo,INP, Playa Ventanas s/n, Manzanillo, Colima,28200, México, Tel: 01 (314) 33 32 37 50; Fax: 01(314) 33 32 37 51; e-mail: teltal@hotmail.com; elespino@bay.net.mx