Rinse and drain crab meat and remove any ligament, cartilage or shell.
Shred crab meat with a fork.
Combine crab meat, mayonnaise, lemon juice and cayenne pepper, to taste, in a bowl.
Stir to blend.
Spread about 1 teaspoon of crab mixture on each cracker and sprinkle with paprika.
Arrange 24 canapes on a large, heat-resistant, non-metallic serving platter.
Heat, uncovered, on roast for 4 to 5 minutes or until heated through.