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Sea animals are an incredibly diverse group of animals that occupy saltwater and freshwater habitats throughout the world.
Their evolutionary history dates back over 500 million years ago. They vary greatly in appearance and structure, ranging from fish to whales.
In this article, we will look at some of the most common aquatic life in English.
Water, Ocean and Sea Animals
To improve your knowledge and expand your vocabulary, we have provided a list of animals, along with a description and image to help you learn more effectively.
Sea, Ocean and Water Animal Names List A-Z
- Antarctic krill
- Beluga whale
- Blue whale
- Great white shark
- Killer Whale
- Rorqual whale
- Sea cucumber
- Sea lion
- Sea otter
- Sea urchin
- Sperm whale
The anchovy is a small fish and one of the most common fish species to consume.
They are found in the Atlantic, Pacific, and Indian oceans, as well as the Black Sea and the Mediterranean Sea.
Anchovies are often used as an ingredient in many dishes, such as pizza and pasta, or they can be eaten straight out of the can.
They are also used in many different kinds of fish bait for fishers all over the world.
This particular fish may suffer from overfishing. When they are overfished, it causes marine life like whales, salmon, sea birds, and other creatures to die.
The Antarctic krill is an invertebrate animal with a transparent body that helps to camouflage it against predators.
Since different types of larger creatures can consume these animals, they often swim in large swarms to avoid being noticed by nearby potential hunters.
Their swarms can have 10,000 to 30,000 krill per cubic meter!
These creatures are found in the Antarctic waters, but they can actually be seen in different parts of the world as well.
The barracuda is a carnivorous, aggressive fish that live in nearshore habitats.
Young barracudas typically live in groups of dozens or even hundreds, called schools.
A great barracuda is one of the fastest fish, with an estimated speed of up to 58km/hr.
The beluga whale is considered to be one of the most intelligent aquatic animals on earth.
They use a variety of vocal sounds in order to communicate with other whales, and they are able to learn new communication skills very quickly.
These creatures spend most of their time swimming up and down through the water while making various types of noises.
Thanks to their white colour, beluga whales can camouflage themselves in the polar ice caps, so they don’t become a meal for other types of animals.
The blue whale is considered to be the largest animal on earth when it comes to size. These creatures are able to grow up to 100 feet long and weigh up to 200 tons, according to National Geographic.
These creatures eat a diet of krill almost exclusively, with up to four tons of krill eaten each day by one adult blue whale.
The blue whale is responsible for making several types of sounds that travel through the water in order to communicate with other whales.
They are extremely loud, and they might be able to be heard by other groups of blue whales up to 1000 miles away from them. This allows the enormous animals to stay in contact with each other.
The catfish is a type of fish that lives in different bodies of water throughout the world, but it is most commonly found in the Americas.
The catfish can be recognized by its whisker-like barbels near its mouth.
It is believed that some species of catfish can live to one hundred years old.
The clam is a filter feeder that squats usually found in sand or mud with its two shells opened widely apart.
This animal has a strong foot which helps it move along the ocean floor so it can find a suitable place to live and locate food more easily.
The clams eat tiny microorganisms and clean the water.
During times when they are in danger, clams will shut their shells tightly and remain very still in order to avoid being noticed by predators nearby.
A star in “Finding Nemo,” the clownfish has become a popular pet.
It is bright orange with three white bars.
All clownfish are born male, but they can switch sex only once.
There are 30 species of clownfish and they live in groups called schools.
Cod is a very popular fish dish to consume, found in the Pacific and Atlantic oceans. It can also be farmed.
The cod lives in shallow waters, making them easy to catch.
They can grow as big as 200 pounds but most are 25 pounds.
The cod population has declined due to overfishing but there are now measures in place to protect them.
Coral is surprisingly an animal, because it doesn’t make its own food.
The structure we called “coral” is made up of tiny coral creatures. They connect to one another and make colonies with form one organism.
They join with other colonies to form reefs.
They obtain nutrients from algae and their tentacles can grab small fish and zooplankton.
The crab is a small animal that has ten legs and has its skeleton on the outside as a shell.
It can be found in oceans all around the world and can be red, blue, brown, white, yellow, or tan in its coloration.
Crabs often like to stay close to rocks and reefs to easily camouflage themselves from predators and other sea animals that might try to harm them.
Crabs keep the coral reef clean from debris that might otherwise harm it.
The crocodile is a large animal that has been known to prey on cows, pigs, birds, fish and any other animals that it can find in its current habitat.
It has four legs and is known for its large jaws that are usually filled with very sharp teeth. They are not able to chew!
Crocodiles can survive months without food. They eat small stones to help their bodies break down food.
The largest species known today is called the saltwater crocodile, and it can be found in tropical regions. They can grow a length of 23 feet!
Dolphins are considered to be one of the most intelligent aquatic animals on earth.
These creatures are extremely social, and they live in a group called a pod that can have up to 1000 dolphins if food is plentiful.
Dolphins use sound waves to determine the size, shape, and speed of faraway objects, in a process known as echolocation.
These creatures are considered to be carnivores that eat whatever they can find in their mouth.
They have long snake-like bodies, and some eels have abdominal organs that are electric!
Eels live alone near caves or rocks where there is not a lot of light which will allow eels to attack their prey more easily.
Goldfish actually originated in China before being introduced to Japan, Europe, and other countries in later years.
They were considered valuable and bred over centuries into rare forms.
Goldfish typically live for about ten years, but some goldfish have been known to live as long as 30 years.
Unfortunately, many goldfish do not reach this life potential due to poor housing conditions.
Great White Shark
The Great White Shark is one of the largest predatory fish on earth.
These creatures often travel great distances in order to find food supplies that will help them survive.
These animals might be considered to be the most dangerous type of shark in the ocean because they are aggressive and have the ability to kill humans.
People who are swimming near the surface of the water might be mistaken as a potential food source for the great white shark; however, research suggests that they only like to take a sample bite from humans before releasing them!
Jellyfish have lived for millions of years even before the time of dinosaurs.
These creatures are considered carnivores with long tentacles that help them grab and paralyze their prey.
Jellyfish stings can be painful and sometimes dangerous.
Jellyfish are considered a delicacy and are found in traditional Chinese medicine.
Killer Whale (Orca)
Orcas, otherwise known as killer whales, are part of the dolphin family. They are not whales!
Despite their name, they almost never attack humans as they are not in their natural diet.
They are sociable and highly intelligent and there is a huge debate whether they should be held captive in marine parks such as Seaworld.
No animals hunt the killer whale. They mainly eat seals, fish, sea birds and squid.
They live in family groups called pods, with up to fifty members.
Lobster is a delicacy and a deep-sea creature found in the ocean.
Lobsters are green, yellow or bright blue in nature. They only turn red when they are cooked. The exception is the white lobster.
Lobsters have claws and a tail that they can curl. They have ten legs that can actually grow back if misplaced!
They eat clams, crabs, starfish and other sea life. If food is very scarce, they eat other lobsters!
The narwhal is a porpoise-like creature living in the Arctic waters.
The narwhal is an animal that has a long tooth that protrudes from the front part of its head.
This tooth resembles a unicorn horn and is made of ivory. This creature does not have many predators, so there is nothing to worry about when it comes to its defense mechanisms.
They travel together and can be found in big groups with thousands of narwhals.
The octopus is a sea animal with eight long arms. They are more commonly found in tropical waters.
Octopuses can change colour to communicate with other octopuses and blend in with their surroundings.
Octopuses can shoot an inky fluid into the water if harmed.
The oyster is a sea animal that is unique compared to most other creatures on this list because it spends almost its entire life living in the same spot.
This animal has a shell-like body and prefers to stay in shallow waters, found in groups called colonies, beds, or reefs.
Oysters have a shell that they can hide in if they feel threatened.
Oysters are considered to be filter feeders, and they play an important role in their habitat by removing impurities from the water around them.
Penguins are seabirds and primarily reside around Antarctica.
While penguins can’t fly, these creatures are able to stay underwater for up to 27 minutes while they look for food.
Climate change is a significant threat to penguins. The penguins depend on ice to build nests and find food.
Penguins have very thick feathers that keep them warm when they are swimming.
They cannot hunt without their waterproof feathers, so they need to fast when they begin losing their feathers during the molting process.
These creatures are considered to be scavenger fish types with razor-sharp teeth.
The piranha can clamp their jaws tightly to their prey. Their teeth act like scissors to cut food.
All Piranhas live in South America, and they live in groups called shoals.
These creatures are considered to be semi-aquatic animals native to Australia.
Platypuses are nocturnal hunters found in rivers, streams, and some lakes.
During the day, the platypus nests in its burrow along the river banks.
They are one of the few animals that lay eggs and are still considered to be a mammal.
Most shrimp are omnivores and scavengers, eating anything they can find, from seaweed to mussels.
Prawns have five pairs of swimming legs as well as antennae; The antennae have sensors that allow them to feel, smell and taste.
Prawns and shrimp are similar, and the terms are often used interchangeably in farming and fishing.
Prawns come from fresh water and are larger than shrimp. Their meat is also sweeter.
The pufferfish, also known as the blowfish, inflates in times of danger. They ingest vast amounts of water or air to turn into an inedible ball.
The pufferfish contains tetrodotoxin, a poisonous substance that is lethal to humans and other animals. In fact, there is enough of this chemical in one pufferfish to kill thirty human adults!
The poison doesn’t stop humans from eating the pufferfish, however.
For an expensive price, the pufferfish can be prepared as a delicacy by trained and licensed chefs.
Despite chefs trying to prepare it as best as they can, it may result in death. Such deaths occur annually.
This animal belongs to the baleen whale family.
The rorqual whale filter feeds on krill, plankton, and other types of ocean creatures.
Most of them breed in tropical waters during the winter and move to polar feeding areas during the summer for their food supply.
Atlantic salmon are often farm-raised; however, wild salmon enjoy both freshwater and saltwater.
They have a streamlined body with a forked tail which helps them move easily through the water until they spot their prey.
Salmon often live alone in deep waters as adults and can grow quite big, with the king salmon weighing up to 57.2kg.
After living many years at sea, salmon are said to come home to the river where they were born to spawn. Salmon usually die within a week or two after spawning.
Sea cucumbers live on or near the ocean floor.
They can consume large amounts of sand and mud from different bodies of water, which helps to ensure that no harmful chemicals or materials make their way into the water supply.
Their slow-moving nature allows them to easily blend into the sand while they wait for their food to swim by.
Once an animal comes close enough, sea cucumbers are able to use their tentacles in order to capture and devour the prey.
These creatures are considered to be carnivores; however, they occasionally eat marine plants and seaweed.
They have long bodies with more prominent, elongated flippers than seals. The flippers allow them to ‘walk’ a little on the land.
They are also much louder and more social than seals. They join in groups called herds or rafts with up to 1500 members.
The sea otters have webbed feet, and are often found floating on the water’s surface on their backs.
Their waterproof furry coats help to keep them warm, and they keep themselves meticulously clean.
They have a varied diet of fish, frogs, birds and even small mammals such as rabbits.
Also known as the sea hedgehog, sea urchins usually live on ocean seabeds and warm waters.
Sea urchins don’t have any bones but they are covered in sharp spines that can cause a great deal of pain if stepped on! Some are poisonous and can sting you.
These creatures tend to move very slowly through the water.
They have sharp teeth and eat algae, plankton, mussels and eat just about anything that floats by.
Some sea snakes spend all their time in the sea. Some divide their time between the sea and land.
These creatures have paddle-like tails which help them to move through water. They don’t have a fin, unlike the eel.
Some sea snakes can stay in the water for up to 8 hours! This is because they can absorb oxygen through their skin.
Sea snakes are the only reptile that give birth in the water.
Watch out! Sea snakes are highly venomous but bites from them are extremely rare.
These creatures live in shallow waters and migrate to deeper waters in winter to escape the harsh weather.
Seahorses are usually carnivorous that eat fish larvae, small shrimp, and other creatures.
Seahorses usually find a mate for life or a long period of time. Every morning, they engage in a ritualistic dance together!
Seahorses are the slowest moving fish and are poor swimmers, but they have a flexible tail that allows them to anchor themselves.
A seal is a pinniped, or one that has fins and lives in the ocean but can come onto land for long periods.
Seals have blubber–a thick layer of fat– which allows them to live in cold waters. Some species of seal even have a fur coat to keep them warm!
Seals have a varied diet, eating fish and other animals.
Some species, such as the elephant seal, can hold their breath for up to two hours in the water! They can also dive thousands of feet underwater, looking for food.
Sperm whales are considered to be the largest toothed whale that lives throughout the ocean.
They have a large brain, and their spermaceti organ helps them determine the location of prey, and it also allows them to know which direction they are going through echolocation.
These animals are known for their ability to dive to extreme depths in order to hunt for food. They can hold their breath underwater for more than 1 hour at a time, allowing them to capture the prey they are after.
Sperm whales are often found in groups called pods. They enjoy eating a ton of fish and squid every day.
This creature has skin that is covered with light-producing organs called photophores.
They also have the ability to change their own color when they feel like they are in danger. Many squids can also produce light and control its intensity.
Their eyes are big and have a good vision that allows them to see in the depths of the ocean.
They have been known to use jet propulsion in order to move through the water quickly.
They also use their dark ink to escape their predators.
Starfish, or sea stars, are interesting marine life with no blood or brain. They usually have five arms, and if one is misplaced, it can grow back!
They can live up to the age of 35. Some starfish can weigh up to 11 pounds, which is very heavy!
Starfish are not actually fish. They are related to sea urchins.
When they eat their prey, their stomach turns inside out! The stomach eats food outside of the body before it comes back into the body again.
Stingrays are related to sharks and don’t have any bones.
These types of fish have barbed spines that are located on their tails. These areas contain venom, which is used to inject any potential predators with a dangerous substance that can help them defend themselves.
Stingray injuries are rare as the stingray is shy and would prefer to swim away.
The stingray is a carnivore that lives in tropical climates with a flat-shaped body and a long tail that has a sharp spine on the end of it.
This spine can be used to defend itself against predators or even humans when necessary, but most people prefer not to touch these creatures because of the way they look.
Stingrays like to eat small fish and other prey items that are swimming nearby.
These animals can spend up to twenty-five minutes with their eyes closed at any given time, but they still make sure to be aware of their surroundings through other senses in case there is danger nearby.
The eyes of a stingray are located on top of its head to allow it to scan the waters above without opening itself up to potential harm.
Tuna is a commonly consumed fish species.
They can reach almost 6.5 feet and 550 pounds.
They are fast swimmers, and some can travel up to 62 miles per hour and can travel large distances in short periods of time.
Tuna release 30 million eggs during spawning, but it’s said that only two survive until adulthood.
Tuna are endangered and are persistently hunted by fishermen.
These animals have been around for millions of years since dinosaurs roamed the earth.
Sea turtles have very unique shells that allow them to quickly swim through the water without being eaten by larger sea creatures.
The shell is also part of their bone structure. It is essentially part of the turtle– you can’t take the turtle out of the shell!
They are among the oldest reptiles. They can live up to 150 years.
All turtles need some water for swimming, and they eat a varied diet of vegetables, aquatic plants, flowers, insects, and fish.
Sea turtles spend most of their lives out at sea swimming up and down until they return to the very same beach where they were born in order to lay their eggs.
These creatures live on ice sheets and tend to stay close together, especially when sunbathing or during mating season when the numbers can grow in thousands.
Walruses use their tusks as defense mechanisms. They continue to grow throughout their lifetime.
Walruses spend most of their life in the water, and their heart rate slows down under the water, so they don’t get too cold.
Sea Animals for Kids
When learning the English language, beginners typically learn the following water animals:
- Sea Horse
- Sea Star (Starfish)
- Sea Lion
Dangerous Sea Animals
There are many types of dangerous sea animals that you should try to avoid because they might be poisonous or just too big for a person to move away from if they attack you.
Stingray, barracuda and sea snakes are examples of dangerous sea animals. Some jellyfish and octopuses are also harmful.
Endangered Sea Animals
Some types of sea animals are on the endangered list because human activity has caused their population to decline. Some species are vulnerable due to a loss in genetic variation.
Some types of turtles, sharks, otters, penguins, salmon, tuna, whales, dolphins, krill and sealions are in danger of becoming extinct.
Extinct Sea Animals
Some types of sea animals used to exist, but now their population has been wiped out, which means the species is extinct.
Some extinct animals include:
- Great Auk
- Japanese Sea Lion
- Stellar’s sea cow
- New Zealand grayling
- Frilled Shark
We hope you found this list of aquatic animals helpful. These animals live in or near water to survive and thrive. There are many more species to learn about, but this is a good start! Don’t forget to share this list with others if you found it helpful!
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I'm an Irish tutor and founder of TPR Teaching. I started teaching in 2016 and have since taught in the UK, Spain, and online.
I love learning new things about the English language and how to teach it better. I'm always trying to improve my knowledge, so I can better meet the needs of others!
I enjoy traveling, nature walks, and soaking up a new culture. Please share the posts if you find them helpful!