Meanwhile, in a large, heavy skillet warm the olive oil over medium heat. Add the shallots and garlic and cook for 2 minutes. Add the shrimp and cook until pink, about 5 minutes. Add the cooked linguine, lemon juice, lemon zest, salt, and pepper. Toss to combine. Turn off the heat and add the arugula. Using a mesh sieve, strain the lemon zest out of the reserved lemon olive oil and add the oil to the pasta. The zest can be discarded. Add some of the cooking water to desired consistency. Add the chopped parsley to the pasta and toss to combine. Serve immediately.