This is a bit dated, but interesting on it's face.
The Food and Drug Administration (FDA) is warning consumers not to buy or eat imported fish labeled as monkfish, which actually may be puffer fish, containing a potentially deadly toxin called tetrodotoxin. Eating puffer fish that contain this potent toxin can result in serious illness or death.
How would you know if the thawed monkfish in the supermarket fish counter was imported or not?
FDA Warning on Mislabeled Monkfish