Porpoises mostly feed on fish. They also eat squid, mollusks, crustaceans, shrimp, cuttle fish, and soft finned fish. They eat non-spiny fish, sardines, herring, cod, and shellfish.
For different habitats there are different diets. Finless Porpoises are reported to eat fish and shrimp in the Yangtze River, and fish, shrimp and squid in the Yellow Sea/Bohai area and off Pakistan....