Smaller fish species are more nutritious, lower in mercury and less susceptible to overfishing, a Cornell-led research team ...

But then a giant freshwater fish arrived ... That means the paiche is eating a lot of fish." Unlike other predatory fish like piranha, it only has small, not particularly sharp teeth.

While no one would blame you for buying giant tuna already cut into fillets, there's a good reason why you should shop for ...

The Marine Conservation Society advises to avoid eating eels as no sustainable source is yet available. Eels are a traditional ingredient in the typical French freshwater fish stew, Matelote.