Although over 90% of our planet is covered in water, we know very little about what really lives in these waters.
Occasionally, we are lucky enough to watch dolphins or turtles come to the surface, but most of the time the life under the water’s surface is hidden.
We take a closer look at some aquatic animals living in the oceans and seas of our world.
Alligators are well known for their large, fearsome appearance.
These reptiles live in freshwater habitats, including marshes, swamps and rivers.
They are apex predators hunting rodents, fish, turtles and other large prey.
Angelfish are reef fish that can be found in tropical waters where they feed on small crustaceans.
The majority of angelfish live in shallow coral reefs but some have been found even at depth of 600 feet.
These deep sea fish live usually in temperate climates all over the world.
They have a long, flesh protrusion on top of their heads which is believed to help lure prey closer to them.
Barnacles may often look like little rocks because they are typically found on hard surfaces, such as rocky outcrops, cliffs or even boats.
However, they are very small sea creatures that feed on plankton.
Catfish are a popular catch with anglers and fishermen. They can be found both in saltwater as well as freshwater.
Catfish have a slender body with protruding whiskers, called barbels, around their mouths.
Clams can be found all over the world, although they prefer to sit on hard sediment, such as cliffs or rocks.
These mollusks only live in saltwater where they can grow from one inch to even eight inches in length.
Since the famous movie Nemo, even small children know what a clownfish looks like.
However, their bright, striped bodies are a warning signals to predators to stay away.
Clownfish themselves are non-aggressive fish, and can even be kept as pets.
Cod is a popular food fish across the world. It can be found all over the Atlantic Ocean, typically in a depth of 200 meters.
Corals can be spotted in both fresh and saltwater.
These small, invertebrates sit firmly on rocks or hard surfaces where they filter the water for plankton.
Crabs can live almost anywhere in the world as they have adapted to both salt and fresh water.
Surprisingly to many, different species of crabs are either carnivores or herbivores.
Crayfish belongs to the family of freshwater crustaceans, and it can live in ponds, rivers, lakes and other bodies of water.
Similar to the alligator, crocodiles are also reptiles that live in and near the water.
They prefer the warm climates of Asia and Africa.
A crocodile’s diet usually consists of small mammals, amphibians and other reptiles.
Cuttlefish are related to squid and octopuses which means that they can change their skin color to seamlessly camouflage themselves.
One off the most friendly aquatic mammals, dolphins can be found in rivers (Also check out Animals That Live In Rivers), coastal areas and in the ocean.
Their social nature means that they usually live in large groups.
Dugong are related to manatees which also makes them marine mammals.
They live in warmer waters in Africa, Australia and Southeast Asia.
As herbivores, they typically feed on seagrass and other marine plants that grow in their preferred shallow waters.
Despite their reputation for being electric, not all eel species can produce an electric shock like Electrophorus electricus.
Their sharp teeth and long, slim bodies makes them ideal hunters in the muddy and murky waters at the bottom of the ocean.
Jellyfish aren’t really fish as their bodies do not have any bones. Instead, they consist of a jelly-like mass.
These large crustaceans usually live in cold water where they can hide in sandy and rocky surroundings.
As herbivores, manatees enjoy warm coastal waters where their favorite aquatic plants grow.
While they do not look very heavy when they elegantly glide through the water, manatees can weigh up to a ton.
Narwhals are whales living in the cold waters of the Arctic Ocean. They usually feed on squid, fish and other invertebrates.
Famous for their intelligence, most octopus species have eight arms and a body with no bones. They can live in both fresh and saltwater.
Oysters attach themselves to rocks in saltwater areas.
These marine animals are so-called filter feeders which means they filter organic material from the water around them.
Piranhas are best known from the frightening horror film. In real life, a piranha is a carnivorous fish that enjoys the warm climates of the Amazon River.
Similar to shrimp, prawns belong to the family of the crustaceans which live in fresh water and salt water.
These water-living animals eat plankton but they also occasionally feed on dead animals.
There are a number of different types of otters, but all of them live in or near the water.
River otters are semiaquatic which means they prefer rivers and coastal areas.
In comparison, sea otters are marine mammals that lives in the waters of the North Pacific Ocean all year round.
Most otters species are known for their playfulness.
With its hard shell, scallops are well protected from predators. Scallops are omnivores eating both animals and plants.
Sea lions are most commonly found along the Atlantic and Pacific coasts and shores where they hunt for squid, crustaceans and fish.
Seahorses are fragile, little sea animals that can be found all over the world’s oceans.
They catch plankton with their long snout.
With their thick fur and fat layer, seals are perfectly adapted to the cold climate of the Atlantic and North Pacific Oceans (see also: Animals That Live In The Pacific Ocean) where they eat squid, fish and crabs.
Known as apex predator, sharks come in a large variety of shapes and sizes.
Some hunt some crustaceans on the seafloor, while larger sharks typically prey on seals and large fish.
There is a vast variety of animals that live in our oceans(you can check out this post to know more about blue animals), and although we may not always see them, they are there to keep a fragile ecological balance.