Using a food processor or blender mince shrimp using on/off turns. Put into bowl and combine with next 9 ingredients (corn - ancho chile). Mix together and place bowl in a larger bowl which is filled with ice and water so mixture will stay cold.
In a large pot over medium heat add oil and then saute the sliced onions and garlic. Stir in tomatoes and chipotles, cover and cook for another 25-30 minutes.
Stir in clam juice or fish stock and bring to a boil.
Divide shrimp mixture into 12 rounded spoonfuls and poach in the soup for 5 minutes, adding additional clam juice until soup becomes too thick.