With its banda beats from the jukebox, squawks from the televisions, and wails from the strolling musicians, Mariscos Altata is a kind of lively Mexican beach party with some of the freshest and most flavorful Sinaloan-style seafood in the Valley. You’ll probably notice a preoccupation with shrimp here, packed raw with a slightly spicy salsa and tomatoes, chiles, onions and cucumbers in a cocktail; tightly wrapped in thick bacon and stuffed with cream cheese; and grilled with a spicy, creamy sauce for crunchy cucaracha you eat shells and all. There are other good dishes, too, like citrus-laden octopus; slithery oysters; and tacos filled with chunks of lightly fried tilapia or stuffed with smoked marlin.