Fun Saltwater Fish Facts For Kids | Kidadl


Fun Saltwater Fish Facts For Kids

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Saltwater fish, also known as marine fish, are found all over the world. This group of fishes lives in diverse and delicate ecosystems in water found in different habitats. These fish species are the most seen fishes in aquariums. They are kept in captivity for entertainment and beautification. These fishes, apart from living in the free world of the ocean, are also grown in farms for widespread sale. Aquafarming under controlled conditions of these fishes is carried out all over the world, not just for commercial purposes but also as a pet culture. This has led to the popularity of saltwater fish in the world but also has brought up a new problem called overfishing. Overfishing is removing the fish species from their natural habitat to such an extent that the fish is unable to replenish in that salt water, leading to population loss. A saltwater aquarium is a big industry in the United States, with over 10 million saltwater fish imported to the country every year.

The saltwater fish comes in many different categories and many different species are bred in captivity. The spiny dogfish and catfish are also part of the group of saltwater fishes found in temperate waters and the northwest Atlantic. Check out some interesting fun facts about these fish only on the Kidadl website.

Fun Saltwater Fish Facts For Kids

What do they prey on?

Looking for fun and interesting facts about a Saltwater Fish? Learn about the amazing mammal and discover other animals from tiny insects to giant mammals!

What do they eat?

Algae, seagrasses, shrimp, plankton, and small crustaceans

Average litter size?

Herbivore, omnivore, and carnivore

How much do they weigh?


How long are they?

2.2-21 lb (1-9.5 kg)

How tall are they?

3.9-70.8 in (10-1800 cm)

What do they look like?

All over the world

Skin Type


What were their main threats?

Slimy Scales, Wet

What is their conservation status?

Humans, food, bigger mammals, habitat degradation

Where you'll find them?





Variable with different species







Saltwater Fish Interesting Facts

What type of animal is a Saltwater Fish?

Saltwater fish are a type of fish found in oceans and aquariums all over the world.

What class of animal does a Saltwater Fish belong to?

As the species found in the group of marine fishes is vast, there is a lot of different classes these species fall in.

How many Saltwater Fish are there in the world?

There are around 15300 species of saltwater fish that currently live their life in the ocean. There are many other categories that have not been discovered yet. While the exact number cannot be derived, it is being found that every year, 150-160 new species are discovered in the salt waters of the world.

An almost similar number of 15000 species of freshwater fish is also found and there are some fishes that can live in both salt water and fresh water.

Where does a Saltwater Fish live?

Different components constitute the saltwater fish habitat. The temperature and the quality of the water are most important. This delicate condition needs to be fulfilled for the survival of this group of species. These fishes are found all over the world and in large groups.

What is a Saltwater Fish's habitat?

The main habitat of saltwater fish is the oceans. The first sign of the presence of these fishes can be predicted with the habitats of rocks, reefs, and sand. The amount of vegetation like the water plants,  algae, and salt marsh is also important for the fish. The saltwater fish can also be found in estuaries, a mixture of saltwater and freshwater, but species like the clownfish cannot survive in these habitats. The clownfish need reefs and only saltwater to survive.

With the United States being the largest business for these fish species, species over 2000 are imported to the US, which is the largest in the world. This has become a common practice in the country now. While many saltwater fish are seen swimming in all the coral reefs found in the ocean, they can also be seen in many offices and homes as the pet culture has become very common. The temperature in the aquarium needs to be 70-80 degrees and the pH needs to be 8.2-8.3. A 55-gallon tank can be a good size for a person starting with keeping these fishes as pets.

Who do Saltwater Fish live with?

Saltwater fish are known to swim and live in solitary, and also have been noticed to stay in large groups. They exhibit this behavior both in their wild habitat and also in the aquarium.

How long does a Saltwater Fish live?

Saltwater fishes can live up to 20 years in captivity, but there have been some instances of few groups living only two to four years in total. However, the wildlife life expectancy is not known.

How do they reproduce?

Marine fishes are known to produce a large number of eggs that are released in the open waters. The average diameter of the eggs ranges from 0.8-1 mm. The eggs are usually small and fragile and the mating season changes from habitat to habitat for these fishes.

What is their conservation status?

Habitat decline, overfishing, pollution, and predation by invasive fishes have led to the population decline of the saltwater fish. Although there are many categories of this group of fish, new ones are found every year. The sea is a vast area to cover and all of the new ones have definitely not been found yet.

There are some saltwater fish that are in danger, and all precautions should be taken to keep their growth in check. Saltwater fish are also eaten by humans as food in many parts of the world. Red snapper and Yellowfin tuna are among the popularly eaten saltwater fishes.

Saltwater Fish Fun Facts

What do Saltwater Fish look like?

Saltwater fishes are known for the dazzling colors and patterns in their body. Commonly known saltwater fish such as clownfish, angelfish, surgeonfish, lionfish, and gobi have distinctive colors and are known to live together. The bright colors and the hardy nature of these fishes make them a perfect companion in an aquarium and are known to be great pets.

The clownfish is a species of the saltwater fish well known for their beautiful colors on the body

How cute are they?

The saltwater fish are very cute with their beautiful colors on the body and graceful swimming.

How do they communicate?

Fishes typically use low-frequency sounds for communication. Some fishes are also known to use movement for the purpose of communicating, but the most usual method is by voice.

How big is a Saltwater Fish?

There are over 15000 known species of saltwater fishes in the world and not much is known about all of them. On average, the measure of the fishes in length ranges from 3.9-70.8 in (10-1800 cm). There are species that can be smaller, or much larger.

How fast can a Saltwater Fish move?

They are pretty quick swimmers but it depends on the species.

How much does a Saltwater Fish weigh?

There can be much bigger saltwater fishes in the world. On average, they can range between 2.2-21 lb (1-9.5 kg) in terms of weight.

What are the male and female names of the species?

The male and female sexes of these fishes are not given different names. They are known by their scientific and common names.

What would you call a baby Saltwater Fish?

Baby saltwater fish is called larvae. They then grow up to be a juvenile.

What do they eat?

Different saltwater fishes are known to be herbivores, omnivores, and some carnivores. Herbivores like surgeonfish are known to survive on different types of algae and seaweed. Omnivores feed on both plants and animals. Carnivores like sharks however are known to feed on other fishes and some invertebrates.

Are they poisonous?

There are some species of saltwater fish that are poisonous. Scorpionfish and Boxfish are examples of poisonous saltwater fish. The Pufferfish is up to 1200 times more poisonous than cyanide for humans.

Would they make a good pet?

In an aquarium, these fishes are known to be hardy and beautiful. They are not simple to care for and need proper care. The water needs to have all the required details correctly managed and even choosing the right fish is important. But with proper research, these fishes can be a great pet to have.

Did you know...

Saltwater fish are known to drink water, unlike freshwater fish that are known to absorb water through their gills and skin.

They need proper care and are harder to take care of than freshwater fishes.

What is the most popular Saltwater Fish?

Clownfish and Angelfish are the most popular fish in this category. They are easy to care for and are pretty affordable too. And the colors they bring in the aquarium are just mind-boggling.

Is a saltwater aquarium hard to maintain?

They were first thought to be hard to maintain and need a lot of different features installed. But as technology and connectivity grew, the availability of the equipment became more accessible and the information on these fishes also became more clearer. Many have tried to keep these fishes as a hobby and succeeded.

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! Learn more about some other fish from our swai fish fun facts for kids and skate fish surprising facts pages.

You can even occupy yourself at home by coloring in one of our free printable Saltwater fish coloring pages.

Written By
Ritwik Bhuyan

Ritwik has a bachelor's degree in English from Delhi University. His degree developed his passion for writing, which he has continued to explore in his previous role as a content writer for PenVelope and his current role as a content writer at Kidadl. In addition to this, he has also completed CPL training and is a licensed commercial pilot!

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