In a 3-quart saucepan heat oil over moderately high heat until a deep-fat thermometer registers 375°F. Working in batches of about 8 and holding sardines at head end to avoid breaking, dredge fish in batter to coat completely, dragging lightly against side of bowl to remove excess, and fry, stirring, until golden, 2 to 3 minutes. With a slotted spoon transfer sardines as fried to paper towels to drain. Fry lime wedges in oil until they begin to turn golden, about 30 seconds, and transfer to paper towels to drain. Serve sardines with lime.
Other Notes
Frying the lime wedges gives them a pleasing golden color and enables the juice to squirt out with the slightest pressure.