Soak bean threads in warm water 10 minutes; drain.
. Drizzle soy sauce over fish, and set aside.
. Combine broth and next 5 ingredients in a deep 12-inch skillet. Bring to a simmer over medium heat, stirring until sugar melts. Add carrot; cover and simmer 5 minutes.
. Add fish; cover, reduce heat to low, and simmer 5 minutes or until fish is firm and centers of fillets are almost opaque (fish should not be completely cooked). Remove from heat; let stand, covered, 2 minutes to allow fish to finish cooking.
. To serve, divide bean threads among shallow bowls. Place fish over bean threads; ladle soup over fish. Sprinkle with green onions, cilantro, and sesame seeds. Serve immediately with lime wedges.