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10 Saltwater Animals

Thick-horned nudibranch (hermissenda crassicornis).
Thick-horned nudibranch (hermissenda crassicornis) Njean/

Are you a fan of marine life and curious about the fascinating world of saltwater animals? Then you’re in for a treat! In this article, we’ll explore the vast and diverse array of creatures that call the ocean their home.



If you’re looking for one of the ocean’s top predators, look no further than the orca, also known as the killer whale. Orcas are the largest dolphin family members and are recognizable by their distinctive black-and-white patterned bodies.

These intelligent and powerful creatures can grow up to 33 feet long and weigh around 22,000 pounds. Orcas are highly social animals and live in groups called pods, consisting of up to 40 individuals.

Orcas are known for their hunting tactics, involving coordinated attacks on other marine mammals such as seals, sea lions, and even other whales. They use their sharp teeth to grab and hold onto their prey and their powerful tails to stun and kill them.

Despite their reputation as apex predators, orcas are not a threat to humans in the wild. There are many stories of orcas helping humans in distress, such as guiding boats to safety or protecting swimmers from sharks.

Unfortunately, orcas like most whales and dolphins face many wild threats, including habitat loss, pollution, and overfishing of their prey.

Sea Horses


If you’re looking for a unique and fascinating creature of the ocean, look no further than the sea horse. These small, upright-swimming fish are found in shallow coastal waters worldwide, including coral reefs, mangroves, seagrass beds, and estuaries.

One of the most striking features of sea horses is their unusual appearance. With their horselike head, long snout, and curled tail, they are unlike any other fish in the ocean. They are also quite small, ranging in size from just 0.6 inches to 14 inches.

Another interesting fact about sea horses is that they are monogamous, meaning they mate for life. During courtship, the male sea horse performs an elaborate dance to attract a female, and if she accepts, they will remain together for the rest of their lives.

Sea horses are also unique in that the male carries and incubates the eggs. After mating, the female deposits her eggs into a pouch on the male’s abdomen, where they are fertilized and protected until they hatch.

Unfortunately, sea horses are threatened by habitat loss and overfishing. They are often caught and sold for use in traditional medicines and as curiosities, and their populations are in decline.

Sea Slugs

Pyjama sea slug.
Pyjama sea slug paulvinten/

Sea slugs, or nudibranchs, are a type of gastropod mollusc that has evolved to live without a shell. They come in various colours, from bright blues and purples to muted greens and browns. Some even have intricate patterns and designs on their skin that make them look like works of art.

One of the most interesting things about sea slugs is their ability to defend themselves against predators. Some species have developed toxic chemicals that make them distasteful or even deadly to other animals. Others have evolved to mimic the appearance of other animals, such as sea anemones or flatworms, to avoid being eaten.

Leopard Seal

Leopard seal.

Leopard seals are carnivorous and have a varied diet, which includes krill, squid, fish, and birds. They are also one of the only seals known to eat other seals. They have been observed hunting and killing young seals, which is a behaviour that is not common in other seal species.

One interesting fact about leopard seals is their unique hunting technique. They will often stalk their prey from below, using the element of surprise to their advantage. Once they have caught their prey, they will use their powerful jaws to crush it before swallowing it whole.


Four walruses.

These creatures are known for their impressive size, distinctive tusks, and ability to live on land and in the water.

One of the most striking things about walruses is their tusks. These long, curved teeth can grow to be over three feet long in some individuals, and they’re used for various purposes.

Walruses use their tusks to help them climb out of the water onto the ice, defend themselves against predators, and to help them break through ice to reach their food.

Walruses are also known for their impressive size. Adult males can weigh up to 3,700 pounds, while females are slightly smaller, weighing in at around 2,700 pounds. Despite their bulk, walruses are surprisingly agile both on land and in the water.

When it comes to their diet, walruses are opportunistic feeders. They primarily eat molluscs like clams and mussels but also other small sea creatures like crabs and shrimp. Interestingly, walruses can use their sensitive whiskers to locate food on the ocean floor, even in total darkness.



These beautiful creatures come in a variety of colours, shapes, and sizes. All starfish resemble stars, and though the most common have only five arms, some of these animals can grow up to 40 arms.

Starfish are part of a group of animals known as echinoderms. They travel using their tube feet, small, suction-cup-like structures that help them move across the ocean floor. Some species of starfish can even regenerate lost limbs, making them fascinating creatures to observe.

Starfish can be found worldwide, and they play an important role in many marine ecosystems. A few species of starfish, such as the reef sea star, have become known as “keystone” species. This means that they disproportionately impact their ecosystem, and their removal can have far-reaching consequences.

Starfish can reproduce sexually and asexually. Some species release eggs and sperm into the water, while others give birth to live young. Starfish can also reproduce asexually by splitting in half and regenerating into two separate animals.


Blue fin tuna.
OpenCage, CC BY-SA 2.5, via Wikimedia Commons

Tuna is a saltwater fish that belongs to the tribe Thunnini, a subgrouping of the Scombridae (mackerel) family. There are several tuna species, including northern bluefin tuna, albacore, yellowfin tuna, southern bluefin tuna, bigeye tuna, blackfin tuna, and longtail tuna.

One of the most impressive things about tuna is their speed and agility. Some species of tuna can swim as fast as 43 miles per hour, which is faster than most other fish. Tuna are also known for their impressive size, with some species reaching up to ten feet in length and weighing as much as 2000 pounds.

Tuna is a popular food fish that is widely consumed around the world. It is a rich source of protein, omega-3 fatty acids, and essential vitamins and minerals. Tuna is also low in fat and calories, making it an excellent choice for anyone seeking a healthy diet.

Manta Ray

Manta ray.

If you want to see one of the most graceful creatures in the ocean, you need to check out the manta ray. These animals are not only beautiful, but they’re also impressive in size. The largest manta ray ever recorded had a wingspan of over 29 feet!

Manta rays are known for their unique appearance. They have large, flat bodies that are wider than they are long. Their pectoral fins on either side of their body are large and triangular, almost like wings. This gives them the ability to glide effortlessly through the water.

One of the most interesting things about manta rays is their feeding habits. They are both macro predators and filter feeders, which means they eat a variety of different things.

At the surface, they ingest zooplankton, including shrimp, krill, and crabs. At greater depths, they eat small to medium-sized fish. To help them catch prey, they have cephalic fins that they can flatten to direct prey into their jaws.

Despite their size and unique appearance, manta rays are gentle creatures that are not harmful to humans. They are pretty curious and will often approach divers and snorkelers.

Moray Eels

Leopard moray eel.
Leopard moray eel charlottebleijenberg/

These creatures are found in saltwater environments all over the world and are known for their unique appearance and predatory abilities.

One of the most distinctive features of the moray eel is their elongated, snake-like body. They can grow up to 13 feet long and weigh up to 66 pounds! Their bodies are covered in a thick layer of mucus that helps protect them from predators and parasites.

Moray eels are also known for their sharp teeth and powerful jaws. They have two sets of jaws, with the second set located in their throat. This allows them to grab and swallow prey whole, even if it is larger than their own body.

Despite their fearsome reputation, moray eels are not typically aggressive towards humans. However, they will defend themselves if they feel threatened, so it is important to keep a safe distance.

There are over 200 species of moray eels, each with their own unique characteristics. Some of the most well-known species include the green moray eel, the spotted moray eel, and the giant moray eel. Each species has its own preferred habitat and diet, and some are more aggressive than others.

In addition to being fascinating creatures to observe, moray eels also play an important role in their ecosystems. They help keep populations of smaller fish and crustaceans in check and are a key part of the food chain in many saltwater environments.

Sea Turtles

Sea turtle.

Sea turtles are known for their distinctive shells, which are made up of hundreds of bony plates that protect their bodies from predators. Their shells can range in colour from brown to green, and some even have patterns on them. Their flippers are also unique, with each one having between two and five claws. They can grow up to six feet long and weigh up to 1,500 pounds.

Sea turtles are omnivores, which means they eat both plants and animals. Their diet consists mostly of jellyfish, seaweed, and crabs. They also eat shrimp, sponges, and other small fish.

Sea turtles lay their eggs on the beach, which hatch after about two months. The baby turtles make their way to the ocean, where they spend the first few years of their lives. Sea turtles can live for up to 80 years and don’t start reproducing until they’re about 20 years old.

Sea turtles are endangered, and their populations are declining due to habitat loss, hunting, and pollution. Many organizations are working to protect sea turtles and their habitats, and you can help by supporting these organizations and being mindful of your impact on the environment.