The title for the "biggest edible fish" depends on whether you are looking at freshwater or saltwater species. In the ocean, the Atlantic Bluefin Tuna is widely considered the largest commonly eaten fish, with record specimens reaching lengths of over 3 meters and weighing up to 680 kg (1,500 lbs). They are prized for their high-fat content and are the most expensive fish in the world for sushi. If you consider "occasional" consumption, the Atlantic Halibut is another massive contender, sometimes exceeding 2.5 meters in length. In freshwater, the Arapaima (or Pirarucu) of the Amazon is the giant; it can grow up to 3 meters and is a vital food source for local communities, known for its mild, boneless meat. While the Whale Shark is technically the largest fish in the world, it is a protected species and is not considered "edible" in a commercial or legal sense. For 2026 sustainable seafood projects, the Bluefin remains the heavy-hitter of the dining world, though it is under strict international quota management to prevent overfishing.