The 20 Stone stingray is considered the largest true freshwater fish in the world. This specimen weighed 280 lb and was caught in Argentina by noted angler and TV host Jeremy Wade after a 4 hour battle.
http://www.dailymail.co.uk/news/art...e-deadly-stingray-hour-standoff.html?ITO=1490
http://www.dailymail.co.uk/news/art...e-deadly-stingray-hour-standoff.html?ITO=1490