Rinse fish in cold water; pat dry. Sprinkle fish with lemon juice; let stand 15 minutes.
Combine 3/4 cup flour and 1 teaspoon salt in a shallow dish; set aside. Combine remaining flour, salt, and paprika in a large mixing bowl. Add beer, beating until smooth.
Dredge fish in flour mixture; dip into beer batter. Fry in 1- inch-deep hot oil (375°) until golden brown, turning once. Drain well on paper towels.
Transfer to a serving platter. Garnish with parsley and lemon wedges. Serve immediately.