Preheat oven to 400° Fahrenheit.
Combine all ingredients except bread and butter in a mixing bowl. Blend to combine being careful not to break up crab pieces too much. Set aside.
Place sourdough bread on baking sheet and place in the oven for about 4 minutes to toast a little.
Remove from the oven, butter bread lightly, and spoon crab mixture over each slice of bread.
Top with parsely and a sprinkle of paprika.
Place back in the oven for approximately 20 minutes or until it looks light and golden brown.
Serve open- face and hot.