1. White Sturgeon
White sturgeon are the largest freshwater fish in North America; they can weigh upwards of 1,500 pounds, measure 20 feet in length and live for over 100 years.
2. Alligator Gar
The Alligator Gar fish on average weighs 100 pounds and ranges in length from eight to twelve feet.
3. Giant Freshwater Sting Ray
The giant freshwater string ray was not discovered by science until 1990. It is an elusive creature that inhabits deep rivers in Southeast Asia, Indonesia, Malaysia and northern Australia.
4. Mekong Giant Catfish
The Mekong giant catfish is often referred to as the gentle giant, because it survives on survives on a diet of plant matter and algae.
Also known as the paiche or the pirarucu, the arapaima is an air-breathing fish found in the rain forest rivers of the Amazon Basin. It is one of the world's largest freshwater fish, reaching 9 feet in length and weighing up to 440 pounds.