Bring 6 quarts of water to boil and add 2 tablespoons of salt.
In a 12 inch to 14 inch saute pan, heat oil over medium heat until smoking and add garlic and lemon slices. Cook until softened and light golden brown, about 3 to 4 minutes. Add fish filets and hot pepper and cook until falling apart, about 6 to 7 minutes. Meanwhile, cook linguine according to package instructions and drain. Toss hot pasta into pan with anchovies and add liquid with pasta water. Add arugula and toss through. Pour into warm serving dish, sprinkle with bread crumbs and serve.