In 2025, the underwater world remains as breathtaking as ever, home to some of the most colossal and awe-inspiring creatures known to humanity. From rivers to oceans, the sheer size and mystery of the world’s biggest fishes continue to captivate marine biologists and enthusiasts alike. Among the most astonishing giants is the Beluga Sturgeon, a relic of ancient freshwater ecosystems. Native to the Caspian and Black Seas, this species can stretch over 24 feet in length and weigh several thousand pounds. Their remarkable longevity and reputation for producing luxurious caviar make them one of the most celebrated, yet critically endangered, fish in existence.
In the warmer, muddier rivers of Southeast Asia, another gentle giant glides through the water the Giant Freshwater Stingray. Known for its immense, flat body reaching over 16 feet across, this stingray is one of the largest freshwater fish species and has become a symbol for conservation efforts in the regionse.
These Are The Top 10 Biggest Fishes In The World
10. Beluga Sturgeon
Maximum Size: Up to 24 feet – 7.2 meters
Weight: Up to 3,500 pounds – 1,588 kilograms The Beluga Sturgeon, native to the Caspian and Black Seas, holds the title of the largest freshwater fish in the world. This ancient species can live for more than a century and is especially famed for producing beluga caviar. Despite its massive size, it faces critical endangerment due to overfishing and habitat loss.
9. Giant Freshwater Stingray
Maximum Size: Up to 16.5 feet 5 meters across
Weight: Up to 1,300 pounds (590 kilograms, Gliding through the murky rivers of Southeast Asia, the Giant Freshwater Stingray is a marvel of nature. Its flat body and whip-like tail make it a formidable presence in freshwater habitats. New conservation efforts in 2025 have shone a light on protecting this elusive river giant.
8. Greenland Shark
Maximum Size: Up to 24 feet (7.3 meters)
Weight: Around 2,200 pounds – 1,000 kilograms The mysterious Greenland Shark, found in the icy waters of the North Atlantic, continues to astonish scientists. Some individuals are believed to be over 500 years old, making them the longest-living vertebrates on Earth. Their slow metabolism and sluggish movements have earned them a reputation as the ghost of the deep.
7. Tiger Shark
Maximum Size: Around 18 feet – 5.5 meters
Weight: Up to 2,000 pounds (907 kilograms)
The Tiger Shark is notorious for its voracious appetite and powerful build. Known to consume anything from turtles to license plates, this predator is a dominant force in tropical and subtropical waters. In 2025, marine studies continue to reveal their crucial role in maintaining oceanic health.
6. Mola Mola – Ocean Sunfish
Maximum Size: 10 feet – 3 meters long and 14 feet – 4.3 meters) tall
Weight: Up to 5,000 pounds – 2,268 kilograms
Looking almost alien, the Mola Mola is the heaviest bony fish in the world. With a round, flattened body, it often drifts near the ocean surface, basking in the sun. Despite its bulky appearance, the sunfish feeds primarily on jellyfish and small invertebrates.
5. Great White Shark
Maximum Size: 20 feet – 6 meters
Weight: Around 5,000 pounds – 2,268 kilograms, The Great White Shark remains the most iconic apex predator of the seas. Popularized by movies and documentaries, the Great White is both feared and revered. In 2025, conservationists are working hard to protect these majestic sharks from threats like overfishing and habitat degradation.
4. Basking Shark
Maximum Size: Up to 40 feet – 12 meters
Weight: Up to 10,000 pounds – 4,536 kilograms Despite its enormous size, the Basking Shark is a gentle giant, feeding exclusively on plankton. It cruises the oceans with its cavernous mouth wide open, filtering vast amounts of water. Sightings of Basking Sharks have increased in 2025, signaling possible recovery efforts in some regions.
3. Whale Shark
Maximum Size: Up to 60 feet (18 meters)
Weight: Up to 20,000 pounds – 9,072 kilograms The Whale Shark holds the title of the largest living fish species. Their spotted patterns are unique to each individual, much like a fingerprint. Although these massive sharks are harmless to humans, they are classified as endangered. Ecotourism focused on whale sharks has become increasingly popular in 2025, promoting awareness and protection.
2. White Sturgeon
Maximum Size: Up to 20 feet – 6 meters
Weight: Over 1,500 pounds (680 kilograms), While not as globally famous as some oceanic giants, the White Sturgeon deserves its spot due to its impressive size and prehistoric lineage. Found along the Pacific coast of North America, these sturgeons are the largest freshwater fish in North America. Conservation initiatives in 2025 aim to preserve their habitat amidst growing environmental concerns.
1. Megamouth Shark
Maximum Size: Up to 18 feet – 5.5 meters
Weight: Estimated around 2,700 pounds (1,225 kilograms), Though not the largest in sheer size, the Megamouth Shark’s rarity and mystique grant it a special place on this list. Only a few dozen individuals have ever been recorded. In 2025, deep-sea exploration missions have led to new sightings, sparking fresh scientific interest in this elusive creature.