What Are the 10 Largest Fish in the World?

The whale shark (Rhincodon typus) is the largest fish on the planet.

It typically grows to about 12 meters (39 feet) long, with some reaching up to 18.8 meters (62 feet) or even 20 meters. Females are generally larger than males and can weigh as much as 21.5 tonnes. Measuring this species can be tricky, which leads to different reported sizes.

Each whale shark has a unique pattern of spots, much like human fingerprints. Scientists use these patterns to identify individual sharks and track their movements.

Unlike many sharks, the whale shark is a gentle filter feeder. It eats plankton and small fish instead of hunting larger prey. Whale sharks are highly migratory, traveling thousands of miles across oceans. They can be found in warm tropical and temperate waters around the world.

Whale sharks have a long lifespan, estimated to be around 70 years or more. Unfortunately, they are classified as "endangered," highlighting the need for efforts to protect this species.

Curious about the bite behind the biggest fish? Dive into our deep-dive on shark teeth.

The basking shark (Cetorhinus maximus) is the second-largest fish and shark in the world. It can reach lengths of up to 12.2 meters (40 feet) and typically measures around 8 meters (26 feet). This species can weigh up to 19 tonnes.

Despite their intimidating size, basking sharks are gentle giants. They feed by filter-feeding on plankton, similar to whale sharks. The basking shark has a distinctively large mouth that it keeps open to filter large volumes of water for plankton.

Unlike whale sharks, basking sharks are primarily found in cooler waters of the Northern Hemisphere, including the North Atlantic and North Pacific Oceans. These sharks undertake long migrations, often following plankton blooms to areas with abundant food.

While not currently endangered, basking sharks face threats from fishing, boat strikes, and pollution.

Another giant fish is the oarfish (Regalecus glesne), recognized for its long, slender body that can reach lengths of up to 17 meters (56 feet). This fish inhabits deep waters, typically found in the epipelagic and mesopelagic zones of tropical and temperate seas.

Unlike most fish, oarfish swim upright, using their long dorsal fin to propel themselves through the water. Oarfish feed on small crustaceans and fish, using their elongated jaws to capture prey.

You may spot oarfish at the surface after storms, where their shiny, silvery bodies reflect the light. Their long, ribbon-like bodies and occasional appearances near the surface have led to tales of sea serpents throughout history.

The oarfish is classified as "least concern," indicating it currently faces no significant threats.

The megamouth shark (Megachasma pelagios) is a unique and large species known for its enormous mouth, which it uses to filter-feed on plankton and small fish and can be up to 1.4 meters (4.5 feet) wide. The megamouth shark was only discovered in 1976, making it one of the most recently discovered large marine vertebrates.

This shark typically grows to about 5 to 6 meters (16 to 20 feet) in length, with some individuals reaching up to 7 meters (23 feet).

Megamouth sharks inhabit deep waters, primarily in the epipelagic and mesopelagic zones of tropical and subtropical oceans around the world. They are rarely seen at the surface, but they occasionally rise to feed during the night. Due to their elusive nature and deep-sea habitat, sightings of megamouth sharks are extremely rare.

As little is known about their population and behaviour, the megamouth shark's conservation status is currently listed as "Data Deficient".

The oceanic manta ray (Mobula birostris) is the largest species of manta ray and certainly qualifies as a giant fish. It boasts an impressive wingspan, reaching between 7 and 9 meters (23 to 29.5 feet), with a flattened body and large pectoral fins. They are known for their graceful and acrobatic swimming behavior, often leaping out of the water.

This creature inhabits tropical and temperate oceans worldwide. Manta rays are filter feeders, meaning they swim through the water with their mouths open, filtering plankton and small fish.

Interestingly, manta rays have relatively large brains compared to other fish, suggesting complex cognitive abilities.

The giant manta ray is classified as "endangered" due to significant threats from overfishing, especially for their gill plates, which poses a major risk to their populations. In response, many countries have enacted protective measures to safeguard these gentle giants.

In our exploration of the largest fish, we cannot overlook one of the most feared sharks: the great white shark (Carcharodon carcharias). This powerful predator can grow up to 6.4 meters (21 feet) long and weigh as much as 2.2 tonnes.

With a robust body and a strong bite lined with sharp, serrated teeth, the great white is well-equipped for hunting various marine animals. These sharks are solitary hunters, often stalking their prey from below. They can dive to depths exceeding 1,200 meters (3,900 feet) and are considered apex predators, sitting at the top of the marine food chain.

Great white sharks primarily inhabit coastal waters worldwide, but they can also venture into deeper oceanic regions. Remarkably, they can live for over 70 years.

While classified as "vulnerable" globally, they face significant threats in certain areas, where they are considered "endangered" due to declining populations.

The Greenland shark (Somniosus microcephalus) is one of the largest fish, reaching lengths of up to 7 meters (23 feet) and weighing over 1,000 kilograms (2,200 pounds). This slow-moving shark has a stout body, a distinctive blunt snout, and small eyes that are well-suited to its dark, deep-sea environment.

Greenland sharks inhabit the cold, deep waters of the North Atlantic and Arctic Oceans. They typically prefer depths between 200 and 600 meters (650 to 2,000 feet) but can also be found in even deeper areas.

While they can hunt live prey, they are mainly scavengers, feeding on the carcasses of marine mammals and fish.

One of the most intriguing aspects of the Greenland shark is its longevity. Some individuals have been estimated to live over 272 years, making them the longest-living vertebrates on Earth. Their slow metabolism and cold-water habitat contribute to their gradual growth.

Greenland sharks are classified as "near threatened." They face several threats, including climate change, overfishing, and habitat loss.

Curious about what it takes to survive in the deep? Check out our article exploring how long sharks live in the wild.

The European catfish (Silurus glanis) is a large freshwater species found in lowland rivers, backwaters, and lakes with abundant vegetation. Their distinctive feature is their long, whisker-like barbels, which they use to sense their surroundings in murky waters.

This fish can grow up to 5.3 meters (17.4 feet) long and weigh over 306 kilograms (675 pounds). It features a scaleless body and a large mouth, which it uses to catch fish and other aquatic animals.

They also have a long lifespan, with some individuals living for over 60 years. European catfish are known for their strong parental instincts. Males guard the eggs and fry until they are able to fend for themselves.

Originally from Eastern Europe and Western Asia, the European catfish has adapted well to various freshwater environments and has spread to other parts of Europe. They are opportunistic feeders, consuming a variety of prey, including fish, crustaceans, insects, and even waterfowl.

Its conservation status is currently classified as "least concern," indicating that it is not facing immediate threats. In fact, in some regions, European catfish have been introduced to new water bodies, where they can become invasive species, disrupting local ecosystems.

The tiger shark (Galeocerdo cuvier) is a large predatory fish known for its distinctive stripes and robust build. It can reach lengths of up to 5.5 meters (18 feet) and weigh over 900 kilograms (2,000 pounds).

Tiger sharks are named for the dark vertical stripes that adorn their bodies, especially in younger individuals. This powerful shark has a wide, blunt snout and sharp, serrated teeth, making it well-adapted for hunting various marine animals.

Tiger sharks are primarily found in tropical and subtropical waters around the world, often inhabiting shallow coastal areas, including bays and estuaries. They are highly versatile feeders, known for their varied diet that includes fish, sea turtles, birds, and even marine mammals.

Tiger sharks are classified as "near threatened," highlighting the need for conservation efforts to protect this iconic species and its role in marine ecosystems.

The pirarucu, also known as arapaima or paiche (Arapaima gigas), is one of the largest freshwater fish in the world and a giant species of South America. It can grow up to 4.5 meters (15 feet) in length and weigh around 200 kilograms (440 pounds). Its body is covered in hard scales, featuring a coloration that varies from green to red.

The pirarucu primarily inhabits the Amazon River basin, thriving in freshwater environments such as rivers and floodplains. Pirarucu is an apex predator in its ecosystem. It feeds mainly on smaller fish, but may also consume waterfowl and small mammals.

A unique characteristic of the Pirarucu is its ability to breathe atmospheric air. It has an accessory respiratory organ that allows it to obtain oxygen directly from the air, which allows it to survive in waters with low oxygen levels.

While it was previously listed as "Data Deficient" by the IUCN Red List, recent assessments suggest that the species is now more stable.

We've just explored the colossal depths of the ocean, but the aquatic world holds many more giants. Let's dive deeper into the realm of massive marine creatures.

• Swordfish (Xiphias gladius): 4 m (13.1 ft)
• Chinese Paddlefish (Psephurus gladius): 3.6 m (11.8 ft)
• Bull Shark (Carcharhinus leucas): 4 m (13.1 ft)
• Bluefin Tuna (Thunnus thynnus): 3 m (9.8 ft)
• Green Sawfish (Pristis zijsron): 3 m (9.8 ft)
• Blue Marlin (Makaira nigricans): 3 m (9.8 ft)
• Paddlefish (Polyodon spathula): 2 m (6.6 ft)
• Lake Sturgeon (Acipenser fulvescens): 1.8 m (5.9 ft)
• Mekong Giant Catfish (Pangasianodon gigas): 1.5 m (4.9 ft)

If you thought these fish were huge, wait until you see the size of some of the ocean’s other giants. Discover the largest marine animals in our next article

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