65 Fun Fish Facts for Kids

Fun fish facts for kids are the perfect way to kick off your non-fiction lessons about fish – including freshwater and saltwater fish species.  

Just like many other types of animals on the earth, there is more to learn than we could ever comprehend. If you are looking for a kid-friendly way to start, the post below includes plenty of tidbits, or fun facts, little learners will love to add to their growing brains.

fish facts for kids

Easy Fish Facts for Kids

This section has ten short and simple fish facts for kids.  These facts are great for the younger kids to comprehend, and can be found in these Building Sentences: Fish Facts for Kids printable worksheets. 

  • Some fish can swim 70 miles an hour.
  • A group of fish is called a school.
  • Fish have very small brains.
  • Fish use sounds to talk to other fish.
  • The great whale shark is the largest fish.
  • Fish swim with fins.
  • Saltwater fish are called marine fish.
  • Fish breathe with gills.
  • Fish are cold blooded.
  • A fish vertebrae is the spine.

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Interesting Facts about Fish

  •  Tail fins on fish are called caudal fins.
  •  There are officially 34,000 species of fish in the world.
  •  Betta fish are small fish you can keep as a pet.
  •  Fish are aquatic vertebrate animals. They have a spine, but no limbs!
  •  A swim bladder is an organ that helps fish stay afloat.
  •  Fish come in many different shapes and sizes.
  •  Pectoral fins are on the sides of fish. Fins help fish steer.
  •  The smallest fish in the world is called Paedocypris.
  •  Bony fish have bones and cartilaginous fish have cartilage.
  •  Fish travel in large numbers so they have easy access to mates!
  •  Some schools of fish have millions of members! That is one large group.
  •  Fish farming raises fish to be sold as food.
  •  Fish have an organ called a lateral line system that helps them detect movement around them!
  •  Electric eels are actually considered fish!
  •  Goldfish have an average lifespan of 7 years. However, some live to be 30 years old!
  • Fish are ectotherms! Their body is almost always the same temperature as the water they swim in.

interesting facts about fish

Different Kinds of Fish

As mentioned before, there are over 30,000 different species of fish on our planet. Some of those live in freshwater and some live in salt water. As you will learn later, some live in both! Below are different types of fish you may have heard of before.

Freshwater Fish

  •  American Shad
  •  Apache trout
  •  Black Crappie
  •  Bloater
  •  Bluegill
  •  Bull trout
  •  Channel catfish
  •  Chum salmon
  •  Lake Sturgeon
  •  Lake Trout
  •  Largemouth Bass

Freshwater and saltwater are two easy ways to divvy up fish into different categories. However, fish are so complex, you could divide them into thousands more categories. 

Fish are all so different from the other. For example, sharks, seahorses, and Bass are all fish! Yet, they seem as different as it gets to many of us. This just goes to show how wide the world of fish really is.

Saltwater Fish

  •  Clownfish
  •  Striped Bass
  •  King Salmon
  •  Bluefish
  •  Redfish
  •  Pacific Halibut
  •  Angelfish
  •  Beardfish
  •  Bonefish
  •  Cod
  •  Eel
  •  Sharks
  •  Flounder
  •  Grouper
  •  Mackerel

There are plenty of fish in the sea.” While that is a phrase typically used to console someone about their love life, it actually rings true! However, the phrase would be more accurate if it was, “There are plenty of fish in the sea, and river, and lake, and many other bodies of water!”

The oceans make up the majority of Earth’s surface and around 97% of all of the water on Earth. So, despite only taking up a microscopic percentage of Earth’s water supply, bodies of freshwater are home to almost half of all fish species! The oceans are so big! How does this make sense? Well, scientists say that most saltwater fish descended from freshwater fish!  You can learn more about sharks in the Ocean with these 30 Cool Shark Facts for Kids.

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Fun Facts about Salt Water Fish

Saltwater fish may be different than freshwater fish, but there are large differences between each type of saltwater fish as well. Some saltwater fish types may have a lot in common! On the other hand, the only thing that one saltwater fish may have in common with another is where they live — saltwater. Here are some facts about saltwater fish in general and some tidbits about specific types of saltwater fish!

  •  Saltwater fish are called marine fish.
  •  Saltwater fish can live alone or travel in very large groups or schools of fish!
  •  Ocean currents are so important for fish! They help bring nutrient-rich waters from the bottom of the ocean to the parts where most fish live!
  •  Reef fish are saltwater fish that live close to coral reefs!
  •  Demersal fish are fish that live on the bottom of the ocean.
  •  Pelagic fish are fish that do not live close to the bottom of the ocean or near the coast. They migrate a lot, but stay away from the bottom and the coasts.
  •  There are five species of salmon that live in the Pacific ocean
  •  Saltwater are generally larger fish than freshwater. They have bigger bones.
  •  The fish in Finding Nemo are clownfish! They love the warm waters in the Red Sea and Pacific oceans.
  •  The biggest fish swimming through the Atlantic oceans is the whale shark!
  •  Saltwater fish drink water! Freshwater fish do not.
  •  Many of the tropical fish that live in tropical waters are extremely colorful!
  •  The Great Salt Lake is one of the largest saltwater lakes in the world! However, it does not have very many fish. It is too salty for fish to thrive.
  •  Seer fish and Indian Mackerel are the most common fish found in the Indian ocean.
  •  Atlantic salmon can travel very long distances! Some will travel over 6,000 miles!
  •  Saltwater fish can be herbivores, carnivores, and omnivores. Sharks are carnivorous fish! Clownfish are omnivores. They eat plants and animals.
  •  Saltwater fish drink saltwater because fish need water inside of their bodies. The salt makes the water leave their bodies very quickly. They need to drink water to make sure they keep up their supply!
  •  Swordfish can swim up to 75 miles per hour!
  •  Most sharks are saltwater fish. They are the only fish that have eyelids!
  •  The batfish plays dead when danger is near! This makes it look like a dead leaf floating on top of water!


Interesting Facts about Fresh Water Fish

The aquatic habitats of fish vary so widely. The fish within those habitats vary widely as well! Almost all of the fish on our planet have descended from freshwater fish, so there is plenty to learn! 

  •  Almost 18,000 fish species live in river basins! There are more than 800 freshwater fish species in North America.
  •  Close to half of all fish species live in freshwater, but only 4% of the water on earth is fresh! So, those freshwater fish must be a little more crowded than saltwater fish!
  •  There are places called estuaries that are in between rivers and oceans. Fish live here and the water is a combination of fresh water and salt water!
  •  Some types of freshwater fish are called anadromous. This means that they hatch from their eggs in fresh water, travel to the sea to live, and then return to fresh water to reproduce.
  •  Other types of freshwater fish are called catadromous. This is the opposite! They are born in the ocean, travel to fresh water to live their lives, and then go back to the ocean to reproduce!
  •  Around 40% of North American freshwater fish species are at risk for extinction. Since 1900, 57 species of North American freshwater fish have gone extinct.
  •  Freshwater fish are extremely important for river, lakes, and other bodies of freshwater. The ecosystems could not survive without them!
  •  The oldest fish species in the world is called the sturgeon. They are an anadromous fish. They live most of their live in the sea, but are born and reproduce in freshwater.
  •  Rainbow trout are a type of freshwater fish with colorfully patterned skin. They have the ability to swim upstream!
  •  Channel catfish are the most common and commonly fished freshwater fish in the United States!
  •  The Bluegill is the easiest freshwater fish to catch!
  •  Some freshwater fish species are called warm water fish species. These fish are fairly adaptable to temperatures, but prefer and do best in warm water. Bluegills, catfish, and crappies are warm water fish!
  •  Coolwater fish are freshwater fish that prefer water between 60 and 70 degrees Fahrenheit. Muskellunge and yellow perks are two types of coolwater fish.
  •  Coldwater fish are freshwater fish that can survive at very low temperatures! Koi and goldfish are two that can survive at very cold temperatures.
  •  Water that is cold holds more oxygen than water that is warm. So, cold water fish require more oxygen to survive!
  •  The GloFish is the brightest freshwater fish! It can come in neon, green, red, orange, blue, and purple. The GloFish a type of fish created by scientists to help discover places of pollution! These fish like to be kept in groups of at least six!

Get your Building Sentences Fish Facts HERE or on TPT


Before you go, here are a few posts you’ll enjoy:

30 Cool Shark Facts for Kids

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41 Fun Pizza Facts for Kids

Ocean Facts for Kids

20 Free Building Sentences Worksheets

fish facts for kids little learning corner

Fish Facts for Kids