Anisakis is a parasite with a life cycle involving what?

• A. A parasite with a life cycle involving fish and marine mammals
• B. A bacteria causing spoilage
• C. A protozoan causing malaria
• D. A fungus affecting shellfish

Answer: (A)

Anisakis is a parasitic roundworm that finishes its life cycle in marine ecosystems, needing both fish and marine mammals. The eggs hatch in the water, larvae are eaten by small crustaceans, fish ingest those crustaceans and harbor the larvae, and finally marine mammals eat infected fish, allowing the larvae to mature in the mammal’s gut. Humans can become incidental hosts if they eat raw or undercooked fish containing the larvae, which can cause anisakiasis. This is why the life cycle is described as involving fish and marine mammals. The other options point to different organisms (bacteria, protozoa, fungi) and don’t fit anisakis.