Peel and devein shrimp; reserve shells. Coarsely chop shrimp.
Combine the shells and water in a medium saucepan; bring to a boil. Reduce heat, and simmer 15 minutes. Strain through a sieve over a bowl. Discard solids. Keep shrimp broth warm over low heat (do not boil).
Melt butter in a medium saucepan over medium heat. Add oil and shallots; cook 2 minutes, stirring constantly. Add rice; cook 1 minute, stirring constantly. Add wine and salt; cook 2 minutes or until almost absorbed, stirring constantly. Add shrimp broth, 1/2 cup at a time, stirring frequently until each portion is absorbed before adding the next (about 30 minutes total). Add shrimp; cook 2 minutes or until shrimp are done, stirring frequently. Stir in parsley, chopped chives, juice, and crab. Garnish with chives, if desired. Serve immediately.