Final answer:
The Food and Drug Administration (FDA) is the primary regulatory agency responsible for the safety of imported fish.
Step-by-step explanation:
The primary regulatory agency responsible for the safety of imported fish is the Food and Drug Administration (FDA). The FDA is a federal agency that is part of the United States Department of Health and Human Services. Its role is to protect and promote public health by regulating and supervising various aspects of food safety, including imported fish.