The name joins 'caguama' (sea turtle), its original main ingredient, and 'manta' (ray), which replaced the turtle once hunting it was banned.
Stewed ray, often with shrimp, sold at seafood stands as a spicy broth or stuffed into corn-tortilla tacos; the broth on its own is called 'bichi', Yaqui for 'naked'.
Why it's made this way: Culinary historian Ricardo Muñoz Zurita traces it to Ciudad Obregón in southern Sonora, from where it spread through Sonora and northern Sinaloa; it is also a popular hangover cure.