Freshwater Fish Identification Guide

Freshwater Fish Identification
  • Post category:Fishing
  • Reading time:6 mins read

If you’re a freshwater fish enthusiast, then this blog post is for you! Here we will explore the different ways to identify and classify various freshwater fish. Some of these include common types like cichlids or catfish while others are less commonly known, such as sunfishes or pupfish. With so many different species out there, it can be hard to keep track of them all. If that sounds like something you need help with, read on!

What is a freshwater fish?

A freshwater fish is any species of fish that lives in a body of freshwater. This includes lakes, ponds, and rivers.

There are many types of these aquatic animals including some common ones like goldfish or bass as well as more specific species such as the American eel or sunfish. Some less commonly known examples include catfishes, cichlids, and pupfish.

Fish Classification:

When it comes to fish, there are a lot of different ways we can classify them! One way is by their body shape or general appearance such as having an elongated or torpedo-shaped body.

We could also classify these animals based on the number of fins they have like whether they have one or two dorsal fins, for example. A third way we could classify these animals is by their habitat such as freshwater fish vs saltwater fish.

This method of classification can get a bit complicated though since many species exist in both habitats and some types are also found partially in brackish water!

One last way to classify these aquatic creatures is by their taxonomic grouping which is based on evolutionary history. This can be done through the fossil record, for example.

With so many ways to classify these animals, it’s easy to get confused! While there are some species that exist in only one habitat or have a unique body shape, other types overlap all of these categories and could even be found partially in brackish water.

For example, the American eel is an elongated fish that lives exclusively in freshwater but can sometimes be found living partly in salty ocean waters as well!

Freshwater Fish Identification:

Now that we’ve got some background on other ways to classify these aquatic animals, let’s talk about how you could identify them. Since there are so many different species, some of which even exist partially in brackish water, it can be hard to keep track of them all!

What’s nice is that you don’t need a degree or any special training to correctly identify these creatures; you just have to know what traits they typically share and use those as your guide.

For example, most fish have scales covering their bodies and fins on the sides of their bodies. Some also have visible gills or a lateral line to help them sense vibrations in the water for things like hunting prey or evading predators.

Other characteristics you could look out for are mouth shape (like is it wide open?) as well as coloration. If you’re familiar with the different types of these animals, then you can use that information to help narrow down your search when identifying them!

Common Freshwater Fish Species :

So now that we know some ways to classify freshwater fish and how they typically look, let’s learn about some specific species so we have an easier time in the field. This way if one pops up, you’ll be able to tell what it is right away!


These crustaceans are found in both freshwater and saltwater. They’re identified by their dark brown color as well as the two large claws on each of their front legs that they use for defense or hunting prey like mollusks. Their claws are also used for getting around and holding food.


Another type of fish that can be found in both freshwater and saltwater, this animal has a long paddle-shaped snout as well as large fan-like scales called scutes on the sides of its body that it uses to swim through water. They’re grayish in color with a white underside and can grow to be as long as 20 feet!

American Eel:  

This fish is typically found only in freshwater habitats but has been known to travel into saltwater at times. It’s distinguished by its snake like appearance that allows it to navigate easily through water, much like an eel. When it lays eggs, they’re released into the ocean but hatch when they reach freshwater.

American Shad:  

These fish are identified by their silver-colored bodies with a white underside and also have dark spots on them. Like other types of fish, these animals can be found both in freshwater habitats as well as saltwater ones!


One of the most common freshwater fish is probably a goldfish which you’ve likely seen in someone’s aquarium. These animals typically have an orange color to them with some black spots and are found all over the world!

They prefer warmer waters so they’re usually not living at higher elevations or places that tend to be colder. If one does happen to live in an area with colder temperatures, it will usually experience slower growth rates or even go into a “winter hibernation” of sorts where they’ll slow their metabolism down and not eat much until the weather warms up again.

Now that you know some ways to identify freshwater fish as well as common species found around the world, hopefully, you can put this information to use when you’re out on the water!

Questions and Answers about identifying freshwater fish.

What are some of the characteristics that you can use to differentiate between these animals?

Scales, visible gills or a lateral line. Mouth shape and coloration.

Are there other species besides fish found in freshwater habitats?

Yes! Crayfish, paddlefish, eels and shad all live in fresh water too.

Do freshwater fish have omega 3?

Yes. Omega-three fatty acids are most commonly found in fish and shellfish.

Are freshwater fish easy to take care of?

Yes. They are pretty low maintenance!

Which is better freshwater or saltwater fish?

Both types of fish offer different benefits and you can find a variety of both in any aquarium.

What do freshwater fish eat?

Some species will feed on plankton, algae or other small organisms while others may even prey upon smaller members of their own kind!

Why freshwater fish cannot survive in seawater?

Their bodies will not be able to regulate the amount of salt in their systems. They need fresh water to survive!

You’ve probably heard that the best way to identify a fish is by its fins and tail. The dorsal fin, anal fin, and pelvic fin are all found near the end of the body on either side of it. Usually they’re easy to spot because there’s no other fins or body parts in their vicinity. When you go fishing, try this trick out for yourself!

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