Ocean Animals: A List Of Animals That Live In The Ocean With Pictures & Facts – Plus FREE question sheet

Ocean animals list for kids (and adults) with pictures and facts. Discover amazing animals that live in the ocean.

Introduction

The ocean covers almost three-quarters of the Earth’s surface and is one of the most important animal habitats. It is home to around 230,000 recorded species, and many more that are still to be discovered and named.

Biologists estimate that the total number of species living in the world’s oceans may be over 1,000,000!

On this page you’ll find an A to Z list of ocean animals, together with pictures and facts about each animal. You’ll also find links that you can follow in order to find more information, plus a FREE question sheet to test your knowledge!

Free Ocean Animals Worksheet Download

Ocean animals worksheet
Ocean animals worksheet: click image to download

You can download a free printable question sheet (in pdf format) for use with this page here.  (No sign-up required; simply download and print.) For more details see: Free Printable Worksheets.


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Ocean Animals List with Pictures & Facts

Albatross

wandering albatross
Wandering albatross

Albatrosses are large seabirds. They have long, narrow wings that allow them to fly great distances using very little energy.

There are around 21 species of albatross (scientists disagree over the exact number). Together they make up the family Diomedeidae.

  • You can find out more about animal groups such as families, orders and species on this page: Animal Classification

The largest albatross is the wandering albatross. Its wingspan can reach 3.7 m (12 ft.); the longest wingspan of any bird! (The southern royal albatross, a closely related species, is a similar size.)

Imagine 2 tall men lying head to toe on the ground; that’s the size of the albatross’s wingspan!

Albatrosses feed on fish, squid, krill and zooplankton. They either find food on the surface of the ocean or dive in to capture their prey.

Albatrosses spend most of their lives at sea. Some are known to travel all the way around the southern part of the world not once, not twice, but three times a year!

Find out more at Active Wild


Anglerfish

anglerfish
Goosefish (an anglerfish in the family Lophiidae)

An anglerfish is a member of a group of carnivorous fish called the Lophiiformes. The group contains several different families, and includes fishes such as the goosefishes, monkfishes, frogfishes, sea toads and seadevils.

Anglerfish are slow-moving ambush predators who get their name from the unique way in which they catch their prey.

Projecting from the top of the anglerfish’s head is a long, bony ‘arm’. A fleshy growth at the tip of the arm acts as a lure to tempt curious fish closer to the anglerfish. (Think of a fisherman using a fake fly to catch a trout.)

When the unsuspecting fish comes within range of the anglerfish’s fearsome jaws, the anglerfish strikes, capturing the prey in its long teeth!


Bivalves

giant clam
Giant clams at Kingman Reef National Wildlife Refuge

Bivalves are a group of aquatic animals with shells. Most bivalves are ocean animals, but some live in freshwater habitats. A bivalve’s shell has two parts. These are hinged on one side, and can be open and closed.

Animals such as oysters, mussels and clams are bivalves. Many bivalves are hunted and eaten by humans. The world’s largest living bivalve is the giant clam.

Bivalves are members of Mollusca, a group of invertebrates whose members are known as mollusks (spelt mollusc in British English).


Coral

coral reef
Coral Reef at Palmyra Atoll National Wildlife Refuge

Corals are marine invertebrates in the phylum (a large group of related animals) Cnidaria. Jellyfish and sea anemones are also members of this group.

Corals are free-swimming larvae for a short period of their lives. After this time they attach themselves to a suitable surface on the sea bed, never to swim again. Corals at this stage of their lives are known as polyps.

The polyps will then either produce more free-swimming larvae, or an exact copy of themselves which will remain attached to the original body.

Corals can continue to produce copies of themselves over many years. As they do so their hard exoskeletons (skeletons that grow outside of the body) gradually combine to create rocky structures known as coral reefs.

Coral reefs are themselves important habitats for many other ocean animals.


Crab

crab
Warty crab / yellow crab (Eriphia verrucosa)

Crabs are members of the animal group Crustacea. Other crustaceans include lobsters, crayfish, krill and barnacles. Most crustaceans live in the sea, but some – such as woodlice – have adapted to life on land.

A typical crab has five pairs of limbs. The front pair is usually modified into pincers, while the other four pairs are used for movement. Most crabs walk sideways rather than forwards.

Crabs are protected by a hard exoskeleton. As the crab grows it periodically molts, removing its entire body – including its legs – from its old shell. Its new shell is soft and expandable, giving the crab enough room to continue to grow.


Dolphin

bottlenose dolphin
Bottlenose dolphin

Dolphins are marine mammals. Although their ancestors were land animals, dolphins are entirely aquatic. Their bodies are streamlined and fish-like, although, being mammals, dolphins still have to come up to the surface to breathe.

Most dolphins are members of the family Delphinidae, a group otherwise known as the oceanic dolphins. With 30 species, Delphinidae is the largest dolphin family.

As the name suggests, oceanic dolphins are ocean animals. Members of the other three dolphin families live in freshwater or brackish (a mixture of fresh and salt water) habitats.

The brains of dolphins are among the largest – in relation to body size – of any animal. Dolphins are highly-intelligent animals, capable of teamwork, teaching / learning, and problem solving.

Find out more at Active Wild


Eel

moray eel
Moray eel

Eels are fish with long, snake-like bodies. Eels have long fins running along much of the length of their bodies. They swim by moving from side to side, making waves that travel down their bodies, pushing them through the water. Eels are also able to swim backwards.

There are around 800 species of eel. Most live in the ocean, but some make their way into freshwater habitats before returning to the sea to breed.

Eels begin life as tiny, translucent larvae that float in the ocean for up to three years before they metamorphose into small eels. A juvenile eel is known as an elver.


Flatfish

flatfish
A plaice in shallow water.

Flatfish are fish with flattened bodies. Both of their eyes are positioned on the top of their bodies. This means that, unlike most animals, flatfish are asymmetrical.

Flatfish are usually found either on or near the sea bed. The tops of their bodies are usually darker than the undersides, providing camouflage against their surroundings.

As larvae, flatfish look similar to other fish, with an eye on either side of their heads. As they pass from the larval to the juvenile stage of their development, one eye (either the left or the right, depending on the species) migrates to the other side of the head. At the same time they begin to swim on their sides, and the skull and jaws become flattened.

Flatfish such as halibut, plaice and flounder are important food fish for humans


Gull

Great Black-Backed Gull
Great Black-Backed Gull

Gulls are a group of between 50 and 60 species in the family Laridae (this family also includes skimmers and terns). Gulls are medium to large birds, usually with white plumage with contrasting areas of grey or black. Most gulls are dark grey or brown as juveniles, becoming progressively whiter with each molt.

The great black-backed gull is the largest species of gull. It has a wingspan of between 144 and 166 cm.

Gulls are social, noisy birds. They traditionally form breeding colonies on rocks and cliff tops, but today are just as likely to nest on rooftops in towns and cities. Gulls mate for life.


Jellyfish

lions mane jellyfish
Lion’s mane jellyfish

Jellyfish, like sea anemones and corals, are members of the invertebrate group Cnidaria.

Jellyfish in the free-swimming, adult stage of their development have round, jelly-like bodies (known as bells) with several trailing tentacles. A jellyfish in this stage of development is known as a medusa.

The tentacles of a jellyfish are equipped with stinging cells.

Although jellyfish stings are painful, they are usually harmless to humans. However, in some cases contact can be fatal. Box jellyfish (a type of jellyfish identified by their square-shaped bells) are the most dangerous to humans.

Jellyfish have a complex life-cycle. They begin life as larvae. At this point they are free-swimming. The larvae then attaches itself to a suitable surface and becomes a polyp.

The polyp then begins to produce buds. The buds float off and eventually become medusae.

Find out more at Active Wild


Krill

Antarctic Krill
Antarctic Krill

Krill may be small, but they play a vital role in the ocean food chain. Krill are crustaceans that spend their lives drifting in the ocean. During the daylight hours they are found in deep water, but during the night they rise up close to the surface.

There are 86 species of krill. Some of these species occur in such great numbers that their population makes up a significant proportion of the total biomass of an ecosystem.

The total biomass of the Antarctic krill, a species found in the Southern Ocean, may exceed 500 million metric tons. This floating feast is an essential part of the diets of many species, including baleen whales, seals, squid, seabirds and fish.


Lobster

lobster
Common lobster

Lobsters are large crustaceans that live on the sea bed. They have five pairs of limbs, with the front pair being equipped with large claws. The other four pairs are used for walking. The two pairs behind the larger front limbs also possess claws.

Lobsters usually walk slowly over the ocean floor, but if alarmed they are able to swim away backwards by curling and uncurling their tail.

Chemicals in the lobster’s blood give it a blue color.


Killer Whale / Orca

killer whales breaching
Killer whales

The killer whale – also known as the orca – is one of the best-known ocean animals. This fearsome carnivore is an apex predator, having no predators of its own.

The killer whale is found in all of the world’s oceans. It is just as likely to crop up in the Southern Ocean near Antarctica as it is in the Arctic.

Despite its name, the killer whale is actually a dolphin (although strictly speaking all dolphins, including the killer whale, are members of the group of animals known as toothed whales). It is a member of the family Delphinidae, also known as the oceanic dolphins.

With large males reaching 8 meters in length and 6 metric tonnes in mass, the killer whale is the largest oceanic dolphin.

Find out more at Active Wild

Killer Whale Facts


Penguin

emperor penguins
Emperor penguins – the largest penguin species.

Penguins are flightless birds that are adapted to an aquatic lifestyle. Instead of flying through the air, penguins ‘fly’ through the water. Using their wings as flippers, penguins are fast and highly maneuverable. They have to be; their prey consists of sea animals such as fish, krill and squid.

Penguins are usually found in cold regions in the Southern Hemisphere. Several penguin species are found on the coast of Antarctica itself.

All penguins have black backs and white fronts. This is an example of countershading – a system of camouflage used by many ocean animals – with the upper regions being darker than the underparts.

From below, the penguin is difficult to see against the surface of the water. From above, it is concealed against the sea bed.

Some penguin species have additional markings and patches of yellow or other colors.

The biggest penguin is the emperor penguin. It reaches a height of around 1.2 m (4ft.). The smallest penguin is the little penguin, which grows to around 33 cm (13 in.)

Find out more at Active Wild


Ray

manta ray
Giant oceanic manta ray

Rays are fish with wide, flat bodies and wing-like fins. Most rays are bottom-feeders, and many have powerful, plate-like teeth for crushing the shells and exoskeletons of their shellfish and crustacean prey.

Rays, along with sharks, are members of the group known as the cartilaginous fishes. The skeletons of fish in this group are made from a flexible substance called cartilage, rather than of bone.

Some or all of the water taken in by rays for ‘breathing’ enters through openings called spiracles, which are positioned on the top of the ray’s body. The water is then passed over the ray’s gills. (Most fish take in water through the mouth alone.)

Stingrays are rays whose tails are equipped with sharp, venomous spines called stingers. These are usually only used defensively.

Stings from stingrays usually occur when swimmers accidentally step on the fish. The sting is extremely painful, but not usually life-threatening.

Find out more at Active Wild


Sea Anemone

sea anemone
A sea anemone (species unknown)

Sea anemones are members of a group of invertebrates known as Cnidaria. Other cnidarians include jellyfish and corals.

Looking like underwater stars, sea anemones have a ring of stinging tentacles positioned around a central mouth.

Sea anemones begin life as free-swimming larvae. Depending on the species, they then either attach themselves to a solid surface or burrow into soft surfaces.

Anemones are not completely immobile. Depending on the species they are able to move in a variety of ways, including crawling, swimming, or floating using a bubble of gas.

Some sea anemones have a symbiotic relationship with other animals. (In nature, a symbiotic relationship is one in which two different species live together and help each other in some way.)

For example, some sea anemones live on the shells of hermit crabs. This gives the anemone a means of moving around, while the anemone’s stinging tentacles provide protection for the crab.

When the crab changes its shell, it takes the sea anemone with him!


Sea Lion

sea lion
South American sea lion

Sea lions are members of the eared seal family, Otariidae. This family is part of a larger group of animals known as pinnipeds, which also contains the true, or earless, seals, and the walrus.

Unlike true seals, sea lions are able to use their hind flippers for walking on land. This makes them slightly more mobile when out of the water than their earless cousins.

There are six species of sea lion. The most familiar of these is the California sea lion. This is the species that is usually seen in zoos and water parks.

Find out more at Active Wild


Sea Snake

sea snake
Blue-lipped sea krait (Laticauda laticaudata) in Ko Samui. Thailand. Image: jurvetson [CC BY 2.0]
Sea snakes are snakes in the family Elapidae that have adapted to life in the ocean. Not all members of this family live in the sea; cobras, for example, live on land.

Most sea snakes spend their whole lives in the sea. They swim using their modified, paddle-like tails, and, rather than laying eggs, give birth to live young.

Sea snakes possess some of the most powerful venom of all snakes. This is delivered via hollow, fixed fangs positioned at the front of the upper jaw.


Sea Turtle

green sea turtle
Green sea turtle

Sea turtles are a group of seven reptiles that, unlike other Testudines (turtles) have adapted to a life spent mainly in the sea. In fact, once a male sea turtle enters the ocean as a hatchling, it will never again walk on land.

Female sea turtles will periodically return to land – often to the very beach on which they hatched –in order to lay their eggs.

The limbs of sea turtles have evolved into flippers. Although able to spend long periods of time under the water, sea turtles always have to return to the surface in order to breathe.

Sadly, sea turtles occasionally get caught up in the nets of fishing boats and drown. Sea turtles are also vulnerable to pollution, mistakenly eating pieces of plastic they find floating in the sea.

This, combined with the loss of many of their traditional nesting areas, means that sea turtles are in great danger.

Three sea turtle species are rated Vulnerable, one is rated Endangered, and two are rated Critically Endangered.

Find out more at Active Wild


Seahorse

seahorse
Common Seahorse

Seahorses are small fish, named after the land mammals that they resemble. There are 45 species of seahorse.

Seahorses are not powerful swimmers. They spend most of the time holding onto marine vegetation with their prehensile tails. (Prehensile means ‘able to grip’.)

Male seahorses have pouches into which the female deposits eggs. The couple’s eggs develop inside the pouch and the young emerge as tiny seahorses.

Find out more at Active Wild


Seal

Hawaiian Monk seal
Hawaiian monk seal

Seals are marine mammals whose ancestors were once land animals. Unlike whales and dolphins, whose ancestors were hoofed mammals, the ancestors of seals were carnivores.

Seals are in the same order – Carnivora – as cats, dogs, weasels and bears.

Seals have many adaptations for living in the ocean. These include having flippers for swimming, a layer of blubber under the skin for keeping warm, and streamlined, torpedo-shaped bodies for moving swiftly through the water.

There are two main types of seal: ‘true seals’ (also known as ‘earless seals’) in the family Phocidae, and ‘eared seals’ in the family Otariidae.

True seals propel themselves through the water using their hind flippers. This adaptation comes at a cost; their hind flippers cannot be used for walking. Because of this, true seals move awkwardly on land.

The true seal family includes familiar species such as the harbor seal, which is the most widely-distributed seal, and the southern elephant seal – the largest seal species.

The eared seal family includes the fur seals and the sea lions. They swim mainly using their front flippers, and are able to reverse their hind flippers and use them for walking when on land.

Find out more at Active Wild


Shark

great white shark
The great white shark is one of the most feared ocean animals.

Sharks are among the best known – and most feared – of all ocean predators. There are over 500 species of shark. Although not all are dangerous, species such as the great white shark, tiger shark and hammerhead shark are all apex predators; top of the food chain wherever they are found.

Sharks are fast, silent, and most species are armed with a mouthful of sharp teeth that are replaced continuously throughout the animal’s lifetime.

All sharks have special electroreceptive organs in their heads. Using these, a shark can sense the electrical fields produced by other ocean animals. This ‘sixth sense’ is used to locate prey.

Sharks are cartilaginous fish. Whereas the skeletons of bony fish (the other main fish group) are made of bone, those of cartilaginous fish are made of a flexible substance called cartilage.

The world’s largest fish – the whale shark – and the second-largest fish – the basking shark – are both sharks. Unlike their smaller, but deadlier cousins, these two giants are filter feeders. Their diet consists of small marine organisms such as krill.

Find out more at Active Wild


Squid

Squid
Caribbean reef squid (Sepioteuthis sepioidea)

Squid are mollusks in the class Cephalopoda. They have soft bodies with an internal shell called a pen, large eyes, a cluster of 8 arms and 2 tentacles. Like all mollusks, much of a squid’s body is enclosed in a muscular wall known as a mantle.

The colossal squid – a squid that can reach 46ft. (14 m) in length – has the largest eyes of any animal. Its eyes can be up to 11 in. (27 cm) in diameter!

Squid move through the water either by using their fins, or by jet propulsion. Jet propulsion is achieved by ejecting water at high speed by contracting the mantle.


Starfish / Sea Star

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Starfish (also known as sea stars) are invertebrate ocean animals in the order Asteroidea. (The name comes from the Greek for ‘star-like’).

Starfish live on the sea bed, where they feed on small mollusks and other marine invertebrates.

Most starfish have five arms, but some species can have over 50. If a starfish loses one or more of its arms, it can re-grow them!


Whale

humpback whale
Humpback whale

Whales are marine mammals. Along with dolphins and porpoises they form the group Cetacea – members of which are known as cetaceans.

Whales are descended from land animals. Their ancestors were hoofed mammals in the order Artiodactyla (a group of animals whose members are known as ‘even-toad ungulates’.

The cetaceans’ closest living relatives on land are the hippopotamus and the pygmy hippopotamus.

There are two types of whale: toothed whales such as the killer whale and the sperm whale, and baleen whales such as the humpback whale and blue whale.

Baleen whales feed by filtering small organisms from the seawater using comb-like structures in their toothless mouths. Toothed whales are carnivorous predators.

Among the whales are some of the largest living animals. The blue whale (a baleen whale) is not only the largest living animal, it is also the largest animal that has ever lived.

Find out more at Active Wild


Worms

lugworm
Lugworm

Worms are invertebrates with long bodies and no limbs. Many unrelated types of worm have adapted to live in the sea. Worms form an important part of the marine food chain, and can act as prey, scavengers, predators and parasites.

Many types of annelid (segmented worms whose bodies are made up of many rings, or segments) live in the sea. This group includes worms such as lugworms and ragworms – both of which are eaten by other sea animals. Some ragworms are also predators themselves.

Sea worms such as osedax (also known as ‘zombie-worms’) are scavengers who help to break down the bodies of larger ocean animals that have sunk to the sea bed.

Some marine worms, such as the ribbon worm Parborlasia corrugatus, are parasites that live on the bodies of other sea animals while they are still alive.

The giant tube worm is a marine worm that is able to live in areas of high temperature and toxicity surrounding deep-sea volcanic vents.


Ocean Animals List For Kids & Adults: Conclusion

On this page you’ve met a wide range of ocean animals, from coastal animals such as penguins that rely on the ocean for food, to deep sea worms that can survive in the most inhospitable of habitats.

We hope that you’ve enjoyed reading about these amazing creatures and that you’ve discovered something about ocean animals that you didn’t already know!

What’s your favorite ocean animal? Have we missed any animals that you think should be on this list? Have you ever seen any of the animals mentioned on this page in the wild?

Let us know in the comments below; we’d love to hear from you!


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