Readers can explore facts about these large and sometimes dangerous marine animals on this list. From the great white shark to the sperm whale, these animals are the largest in their environments. They are skilled hunters whose power over their domain should not be underestimated. Despite this, many are threatened by human-caused climate change, overhunting, and more. 

Leopard Seal

Size: up to 11.5 feet in length and 1,320 lb 

Preys on: birds, fish, other seals, and cephalopods

Leopard Seal showing its teeth
Leopard seal showing off its teeth

The leopard seal is of the most powerful predators in the Earth’s oceans. Also known as a sea leopard, this creature is the second-largest species of seal in the Antarctic. The seal has a long and muscular body and massive jaws, making it one of the most feared carnivores in its environment.

The seals have a distinctive leopard pattern in addition to their silver-gray blended colors. They grow to an average of nine feet in length and weigh up to 1,320 lb. 

Bull Shark 

Size: up to 8 feet long and 290 lb

Preys on: bony fish, smaller sharks, stingrays, turtles, and more

Bullshark swimming
Bull shark swimming in dark ocean waters

The bull shark, also known as the Zambezi shark, is a requiem shark (like the tiger shark). It prefers to live in warm, shallow waters along the coast. The shark is considered to be quite aggressive in its natural habitat. Bull sharks are often responsible for near-shore shark attacks.

Female bull sharks are larger than males, reaching up to 8 feet and weighing close to 300 pounds. They have an incredible bite force of 1,300 lbs. 

Bullshark upper teeth
Bull shark upper teeth

Polar Bear

Size: up to 9.8 feet long and 1,000+ lb

Preys on: mainly seals

Two polar bears on the ice
Two polar bears walking on the ice

While mainly a land animal, the polar bear is still considered to be an apex predator in its marine environment. They live within the Arctic Circle and the land surrounding it. Polar bears are the largest living bear species, weighing more than 1,000 lb. They spend most of their lives on the ice, despite being born on land.

They hunt their food from the edge of dwindling sea ice. This is one of the many reasons that polar bears are threatened.

Tiger Shark 

Size: up to 16.5 feet long

Preys on: fish, seals, dolphins, birds

Tiger shark in the Bahamas
Tiger shark in the Bahamas

The tiger shark is a requiem shark and can reach lengths of around 16.5 ft or 5 meters. They are usually found in tropical and temperate waters in and around the Pacific islands. They are named for the dark stripes down the sides of their bodies, which are said to resemble a tiger.

Tiger sharks are solitary creatures and night hunters. They prey on fish, seals, birds, dolphins, porpoises, and more. Tiger sharks as listed as “near threatened” due to hunting, specifically finning. 

Sperm Whale 

Size: up to 67 feet long

Preys on: squid, octopuses, rays, etc. 

Sperm whale diving with calf
Sperm whale diving with calf

The sperm whale is the third deepest-diving mammal in the world and has the largest brain of any animal. The sperm whale is one of the largest whale species in the world. It can grow to around 67 feet (around 20 feet shorter than the blue whale) and live to 70 years of age and longer. 

The distinctive whale has a large, blocky head that takes up a great deal of the animal’s total length. The blowhole is S-shaped and located close to the front of the head. Sperm whales can dive between 300-800 meters or 980-2,620 feet in search of food. They eat everything from squid to octopuses and rays.

Great White Shark 

Size: up to 21 ft and 2,400 lbs.

Preys on: sea lions, fish, and smaller sharks

Great White Shark from below
A Great White Shark swimming from below

Great white sharks are one of the most powerful predators in the Earth’s oceans (and descendants of the Megalodon, the largest shark species of all time). They are also the largest predatory fish, weighing in at 1,151–1,700 lb. The females are usually larger, sometimes reaching 2,450 lb. They are also between 15-16ft.

Great white sharks are incredibly adept hunters. They can move at a speed of up to 21 mph and have an impressive row of around 300 serrated teeth. Like orcas, they have strong jaws and incredibly biting power.


Size: up to 26 feet long and 8,800 lbs. 

Preys on: fish, other larger and smaller whales, seals, sharks

Orca underwater
Orca underwater

Orcas are widely distributed, more so than any other mammal. They live in the coastal areas surrounding most countries and are capable of adapting to any climate.

Orcas have a diverse diet. Some only eat fish while others hunt, something that has led to their name, “killer whale.”

They prey on mammals, like seals, as well as other dolphins. Orcas have even been known to attack larger whales, like baleen whales. Orcas sometimes beach themselves to catch seals on land. Meaning they jump out of the water, land on the ice or shore, latch onto their prey, and drag it back into the water.


What is the apex predator of the ocean?

Orcas are generally considered to be the apex predator in the Earth’s oceans today. These large and powerful whales hunt everything from great white sharks to other whales. Scientists even recorded one instance in which a pod of orcas worked together to kill a blue whale.

What are the top three apex predators?

On land, some of the most powerful apex predators include the lion, saltwater crocodile, brown bear, and tiger. In the Earth’s oceans, the orca and the great white shark reign supreme. 

What is the greatest predator of all time?

Scientists believe that the largest land predator ever to live was the Spinosaurus. This now-extinct dinosaur lived 90-100 million years ago and was around sixty feet long and twelve feet tall. 

Did the Megalodon have any predators?

The Megalodon is commonly considered to be one of the greatest predators in Earth’s history. These enormous ancient sharks preyed on everything the oceans had to offer. The only predator they had to be aware of were orcas who, working in pods, could take down an adult Megalodon. Their young often fell prey to these powerful whales. Scientists speculate that orca pods are responsible for decimating Megalodon nurseries and leading to their extinction.

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