What the word 3 pictures of fish

Fish are some of the most diverse types of animals on the planet, with there being close to 35,000 different species! Fish inhabit water bodies whether that be freshwater in ponds, lakes, streams and rivers or saltwater in oceans- or sometimes both. Regardless of the sheer number of fish species, all species can be broken into three main taxonomic groups or superclasses. In this article, we will cover the three types of fish.

These groups are the bony fish, the cartilaginous fish, and jawless fish. We will dive into these three types and what makes them different from one another. We’ll also list some examples of each type of fish, with pictures, to help you better understand the differences.

Bony fish

What are bony fish?

Bony fish make up the most diverse group of vertebrates and types of fish on the planet, and there are over 28,000 species! As the name implies, bony fish are in fact bony. Meaning they have bones. To be more specific, their bones are made of bone tissue similar to the tissue that makes up our own bones that contain collagen, calcium and other minerals.

What makes bony fish different from other fish?

One telling characteristic of this group is the presence of overlapping scales covering the body. While most people assume that all fish have scales, this is actually a characteristic unique to the bony fish. These scales protect the body as well as a layer of mucus secreted from mucous glands.

Additionally, bony fish have a swim bladder located inside the body. Swim bladders are essentially evolved lungs that their primary function is to help regulate buoyancy. This allows fish to maintain their position without floating or sinking or requiring too much effort from paddling to do so.

Bony fish also have an operculum, which is a large disc-shaped flap that covers and protects the gills. When they open their mouths, this pushes water through their mouth and over their gills, which forces their operculum open.

Most often when we think about a fish, we picture a bony fish. The following types of fish are examples of bony fish, that you may have heard of.

1. Goldfish 

Scientific name: Carassius auratus
Type: Bony

Most people are familiar with Goldfish and many people have kept them as pets. They are commonly thought to be unintelligent, almost mindless fish, however they are actually very socially intelligent. Owners may notice that their Goldfish excitedly swims towards them when they approach the tank. In the wild, they are found in freshwater bodies in East Asia.

2. Parrotfish

Scientific name: Family Scaridae
Type: Bony

There are nearly 100 species of Parrotfish, all of which tend to inhabit tropical or subtropical waters. Parrotfish are typically very colorful, with pink, purple, green and blue scales covering their body. They get their name from their jaws which form almost like a parrot-like beak that they use to crush and scrape coral while feeding.

3. Betta fish

Scientific name: Betta splendens
Type: Bony

Betta fish, also known as Siamese fighting fish are a species of freshwater fish that are commonly kept as pets. They are well known for their brightly colored, large, flowing fins as well as their territorial nature. Males will actually fight to the death if housed together. In the wild, these fish are found in stagnant or slow moving freshwater bodies in Southeast Asia.

4. Winter flounder

Scientific name: Pseudopleuronectes americanus
Type: Bony

Winter flounder, like other species of flounder, are flatfish that spend much of their life on the sea floor buried in the sand. These fish start out their life with one eye on each side of their head, but as they grow both eyes move to the right side of their body. Winter flounder inhabit the northwestern coasts of the Atlantic.

5. Ocean sunfish

Scientific name: Mola mola
Type: Bony

The Ocean sunfish is arguably the heaviest species of bony fish in the world and on average can weigh up to a whopping 550 to 2,250 pounds! They are strange looking fish that are large and vertically flattened with a long fins protruding from either side of their body. They occur in all tropical and subtropical oceans throughout the world.

6. Clownfish

Family: Pomacentridae
Type: Bony

It was a clownfish that was featured in the popular Disney movie, “Finding Nemo”. There are actually many different species of clownfish, but they tend to all share a similar barred pattern. Clownfish are tropical fish and actually depend on anemones for shelter where they will hide from predators or other threats.

7. Atlantic salmon

Scientific name: Salmo salar
Type: Bony

Atlantic salmon are a popular sport-fish and menu item at seafood restaurants. Like other species of salmon, they are born into a freshwater system but will travel to the sea to spend most of their life. Salmon then return to freshwater to breed and reproduce.

8. Moray eel

Family: Muraenidae
Type: Bony

There are nearly 200 different species of Moray eels, however most people associate Moray eels with being bright, lime green which is true of some species. These fish tend to have large jaws with many sharp teeth, some of which stick out of their mouth and can give them an almost sinister look.

9. Atlantic goliath grouper

Scientific name: Epinephelus itajara
Type: Bony

Named for it’s impressive size, the Atlantic goliath grouper is an impressive saltwater fish that can grow up to 8 feet and length and nearly 800 pounds. They tend to inhabit coral overhangs and underwater caverns. They occur in tropical and subtropical waters, however large concentrations of them can be found in the Caribbean.

Cartilaginous fish

What are cartilaginous fish?

Cartilaginous fish are vertebrates, and types of fish with skeletons made out of mostly cartilage. Cartilage is a strong, yet flexible and lightweight material made out of several proteins and fibers. In many animals, humans included, cartilage can be found throughout the body as a connective tissue between bones and joints. Humans also have cartilage in their nose, ears and ribcage.

Having a skeletal system made up of cartilage can be an advantage for these types of fish because the lightweight nature of their skeleton allows for them to travel quicker and further while expelling less energy. Cartilage is also very flexible, meaning that these fish can quickly change directions, bend and turn, making them more agile.

What makes cartilaginous fish different?

This group of fish have scales, but these scales are different from those of bony fish. These scales are called dermal denticles and are essentially very tiny teeth and gives the skin a rough, sandpaper like texture.

Unlike bony fish, cartilaginous fish lack an operculum. Instead, they have 5-7 gill slits that are obvious and present on the body. Additionally, this group of fish lacks a swim bladder and often must mechanically adjust their buoyancy by adjusting their fins.

Below are several examples of cartilaginous fish, however for even more examples you can check out this article.

1. Whale shark

Scientific name: Rhincodon typus
Type: Cartilaginous

Whale sharks are the largest fish in the world by length and can grow as long as 62 feet in some cases, however most are between 40 and 50 feet. Despite their large size, these sharks are completely harmless and are actually filter feeders that eat microscopic invertebrates called plankton.

2. Thorny skate

Scientific name: Amblyraja radiata
Type: Cartilaginous

Skates, like the Thorny skate look very similar to stingrays due to their flattened bodies and they are closely related. However, skates lack the venomous barb that stingrays have and are completely harmless. Thorny skates get their name from the small thorn-like scales on their back. They are native to the Atlantic Ocean and prefer cooler water temperatures.

3. Blacktip reef shark

Scientific name: Carcharhinus melanopterus
Type: Cartilaginous

Blacktip reef sharks get their name from the black markings on the tips of their fins. They are a small shark, typically growing to be about 5 feet in length. They occur in tropical and subtropical waters of the Indo-Pacific. Blacktip reef sharks tend to stick to very shallow waters and thrive on coral reefs.

4. Nurse shark

Scientific name: Ginglymostoma cirratum
Type: Cartilaginous

While most sharks steer clear from people, Nurse sharks are fairly common and seemingly unbothered by people swimming near them. It is not necessarily uncommon for snorkelers or divers to encounter Nurse sharks while swimming. This species of shark is widespread and can be found in warm waters in the Atlantic and Pacific ocean.

5. Bonnethead

Scientific name: Sphyrna tiburo
Type: Cartilaginous

Bonnetheads are a small species of hammerhead shark, however they have a more rounded or shovel shaped head than their relatives. They typically only grow to be 2-3 feet long. Interestingly enough, they are known to be the only species of omnivorous shark and consume both other living organisms and plant material.

6. Greenland shark

Scientific name: Somniosus microcephalus
Type: Cartilaginous

The Greenland shark is an impressive, prehistoric looking shark. This species is capable of living very long lives, with some individuals living to be between 300 and 500 years old! They are incredibly slow moving which allows them to maintain a very slow metabolism. They are secretive sharks and live deep in the Atlantic and Arctic ocean.

7. Sand tiger shark 

Scientific name: Carcharias taurus
Type: Cartilaginous fish

The Sand tiger shark looks like a stone-cold killer with it’s sharp, protruding teeth. However, these sharks have never been involved in any human mortalities and they tend to be uninterested in people. They can be found in tropical and subtropical waters along the coast of all continents except for Antarctica.

8. Bat ray

Scientific name: Myliobatis californica
Type: Cartilaginous

Bat rays are not at all related to bats, however they get their name from their wide, wing-like fins and darkly colored skin. They are native to the cool waters of the Pacific and can be found along the coast of Oregon and California. Like other stingrays, they have venomous barbs on their tail.

Jawless fish

What are jawless fish?

The Jawless fish are a relatively small group of only about 120 species. This type of fish is very unique, due to their body shape. The jawless fish group includes lampreys and hagfish, which are long, eel-like creatures with a disc shaped mouth that have rows of teeth that help to create almost a suction cup.

Jawless fish are covered in skin rather than the overlapping scales seen in bony fish. Some species have very productive mucous glands and have a thick layer of slime covering their body.

What makes jawless fish different?

Aside from their circular mouth, jawless fish are easily identified by their gills, which are actually more like small holes or pockets that run in a straight line along their body, rather than parallel gill slits. Additionally, they tend to lack paired fins and instead have dorsal and tail fins.

While they are different from cartilaginous and bony fish in a lot of ways, they actually have one major characteristic in common with cartilaginous fish which is the presence of a skeleton made out of cartilage.

Here are a few types of fish that are also examples of jawless fish.

1. Sea lamprey

Scientific name: Petromyzon marinus
Type: Jawless

Sea lampreys are parasitic fish and will suction onto other fish to feed on the tissue of their victim, earning them the nickname “vampire fish”. They are also an invasive species in the Great Lakes and have been linked to population declines of native fish. They are able to inhabit both salt and freshwater and are very hardy and resilient fish.

2. Hagfish

Family: Myxinidae
Type: Jawless

There are several species of hagfish, also known as slime eels. They get this name from their very active slime glands that produce large amounts of thick, sticky mucous. In fact, when agitated by being handled, they can produce up to 5 gallons of this substance.

3. European river lamprey

Scientific name: Lampetra fluviatilis
Type: Jawless

European river lampreys are certainly less vicious than their saltwater dwelling relative, the Sea lamprey. This species is somewhat smaller, and is between 10 and 16 inches long. European river lampreys are found almost throughout all of Europe and are also found along the coast of the Mediterranean Sea.

The Earth consists of land and water but we are covered with water. There are many kinds of water forms like rivers, lakes, oceans, seas, and bays. Each water form has different living organisms and many species of fish. 

Fish in the oceans and seas are the common species that are well-known because it has been portrayed in some movies like Finding Nemo. But have you ever wondered what type of fish can be found in the river? 

Today, we are going to talk about the types of fish that can be found in a river!

These Are The Types Of Fish Found In A River

Starting in the southern USA you can find:

Bass Fish

The name bass is a name shared by many species of fish, which means that many fishes have a bass on their name. They are all freshwater fishes below the large order Perciformes. 

Bass Fishes can be found in freshwaters. Large amounts of bass fish can be found in the river and lakes. They are living in St. Lawrence, Great Lakes, Hudson Bay, and Mississippi river basins. 

Bream Fish

The common bream is a freshwater fish that lives in European rivers. They belong to the family Cyprinidae. Also, the common bream is the only species in the genus Abramis. 

The bream has a length of 30 to 60cm even though there are some breams recorded to have a 75cm length. Breams usually weigh 2 to 4kg. The bream’s recorded maximum weight is 9.1kg and the maximum length recorded is 90cm.

The common bream usually inhabits rivers, especially rivers in Europe. They can also be seen in the Balkans and some seas like the Caspian Sea, Black Sea, and Aral sea. But commonly, common breams used to live in ponds, lakes, canals, and rivers. 

Carp Fish

Carps are a species of fish that are oily and live in freshwater. They belong to the family Cyprinidae, and most of them are native to Europe and Asia. Some carp species began to spread in some parts of Africa, Australia, and the United States. 

Carp species are large freshwater fish, and they can be found in many countries. They inhabit rivers, lakes, and ponds. Carp are the usual food of humans and some omnivore animals like dogs and cats. 

Catfish

Catfish have the three largest species alive, and different species have different sizes and behavior. What are those three? The Mekong giant catfish can be found in Asia, the wels catfish in Eurasia, and Paraiba in South America. 

There are many types of catfish, and they differ in size, shape, and behavior. Catfish usually eat clams, snails, insects, and even small birds. 

Catfish can be found mostly in rivers. They also live in deep holes in ponds and rivers where they usually hang out and wait for food. Catfish can also be seen in creeks flowing into any body of water. 

Chinook Fish

The chinook salmon is the largest species of Pacific salmon, and they belong to the genus Oncorhynchus. They have blue-green, red, or purple on the back and top of their head. Also, they have silvery sides and white ventral surfaces. 

The chinook salmon can usually be seen in the Arctic, northwest to northern Pacific. They can also be seen in Honshu Japan and the other sea in Japan. 

Chinook salmon don’t stay long in the river, but they can be seen in the river sometimes. They hatch in freshwater streams and rivers. After that, they migrate to saltwater environments to feed and grow.

Crappie Fish

Crappies inhabit North American freshwater, and they belong to the sunfish family Centrarchidae. There are two recognized species under this genus, and they are the white crappie and black crappie. 

Crappies can be found in a flat adjacent creek or river channels. The bigger crappie tends to hold in deeper water. You can also see them isolated in any weed patches, stumps, or logs. 

Crappies usually eat in the fall, and they feed on smaller species of fish. They also love to eat crustaceans, zooplankton, and a bunch of insects. 

Goldfish

The goldfish is a freshwater fish that belongs to the family Cyprinidae of the order Cypriniformes. Goldfish are one of the most common fish pets of humans, and you can see them in any place with an aquarium.

They are a small member of the carp family, and they are native to East Asia. There are many different goldfish breeds, and they differ in size, body, shape, color, and fin. The colors of goldfish are yellow, orange, red, brown, and black.

Goldfish are abundant in the rivers and lakes of eastern and central Asia. However, many goldfish migrated and now can be found in the freshwater of Europe, South Africa, Madagascar, and America. 

Guppy

The guppy or the million fish is one of the most abundant tropical fish, and they are also one of the most popular fish pets for humans that love to take care of freshwater fish. They belong to the family Poeciliidae. 

Guppies originate from the freshwater ecosystems of South America, but because some species migrate, they can now be found all over the world. They are native to Antigua, Barbados, Brazil, Guyana, Jamaica, and the USA. However, guppies have been introduced in many countries except Antarctica. 

Guppies can be seen usually in rivers. Other guppies inhabit other freshwater ecosystems like ponds, lakes, and creeks.

Koi Fish

Koi fish is a fish that has different colors, and they are one of the preferred pet fish of peoples in Asia. They are used for decorative purposes in outdoor koi ponds, water gardens, and aquariums. Koi fish originated from Niigata Japan.

Koi fish are native to freshwater ecosystems around the Black, Caspian, and Aral seas. They have been domesticated in the 19th century and have been introduced around the globe. Koi can also be seen in rivers, ponds, and lakes. 

Perch Fish

Perch is a name for fish under the genus Perca. They are freshwater fish that belong to the family Percidae. There are three species of perch genus that have been recognized. They are the European perch, Balkhash perch, and Yellow perch.  

Perch are carnivorous fish that can be found in freshwater ecosystems like small ponds, lakes, streams, or rivers. They love to eat smaller fish, shellfish, and some insects. Perch fish usually spawn during the springtime when female perches need to lay eggs. 

Northern Pike

Northern pike fish is a carnivorous fish of the genus Esox. They can be usually seen in freshwater ecosystems of the Northern Hemisphere. Northern pike is only called pike in Britain, Ireland, and Eastern Europe, Canada, and the United States.

Pike are living in streams and weedy places in lakes, rivers, and reservoirs. They are ambush predators where they wait for prey and then strike at full speed. Pike inhabit any freshwater ecosystems where fish and food is abundant. 

Piranha

A piranha is a member of the family Serrasalmidae. They are freshwater fish that inhabit South American rivers, floodplains, lakes, and reservoirs. Piranhas also inhabit the Amazon River. They are carnivorous and love to eat small fish.

There are many species of piranha, and some species can be dangerous to humans. However, some species can be kept as a pet. If you are planning to buy a pet piranha, make sure to research first before getting one. 

Rainbow Trout

The rainbow trout is a species of salmonid that is native to cold-water tributaries of the Pacific Ocean in both Asia and North America.

Rainbow trout usually spawn and can be seen in early to late spring when the water temperature reaches at least 42 to 44 Fahrenheit. The maximum lifespan of a rainbow trout is 11 years old.

Salmon

Salmon is a common name for fish that belongs in the family Salmonidae. Other fish belong to the same family of salmon as trout, char, grayling, and whitefish. 

Salmon are anadromous, which means that they go to freshwater to hatch eggs and migrate to the ocean. They only return to freshwater ecosystems again to reproduce. However, most salmons are restricted to the freshwater ecosystem throughout their lives. 

Salmon are native to tributaries of the North Atlantic and the Pacific Ocean. There are many species of salmon that have been introduced into other environments like the Great Lakes of North America and Patagonia in South America.

Tench Fish

Tench or commonly known as doctor fish in freshwater and brackish fish under the Cypriniformes order. They are living in Eurasia from Western Europe, including the British Isles. Tench love to inhabit slow-moving freshwater habitats like rivers. 

Tench inhabit freshwater ecosystems, and they love to spend their time close to vegetation or patrolling gullies to look for food like snails, bloodworms, and daphnia. They usually live in rivers, ponds, and lakes. 

Tilapia

Tilapia have many species swimming around the world. They are popular in all countries around the world because of their low price, easy preparation, and good taste. Tilapia is also one of the favorite foods of omnivore and carnivore animals. 

Tilapia are freshwater fish that inhabit shallow streams, ponds, rivers, and lakes. They are living in every freshwater ecosystem around the world. 

Trout

Trout are species of fish belonging to the genera Oncorhynchus, Salmo, and Salvelinus. They are closely related to salmon and char species. Trout also love to swim under freshwater ecosystems. 

Trouts usually live in cool and clear streams, lakes, and rivers. They are one of the fishes that live in the river. Trout can be seen throughout North America, North Asia, and Europe. 

Walleye

The walleye is a perciform fish that lives in the freshwater ecosystems of Canada, and the Northern United States. They are closely related to European zander, commonly called the pikeperch. Walleyes can grow to about 80cm, and they can weigh up to about 9kg. 

Walleyes are living in freshwater habitats like rivers, lakes, and ponds.  

Are River Fish Safe To Eat?

Many people love to ride a boat and catch fish. People capture themselves with cameras or mobile phones when they caught a giant fish. They brag about the fish they caught, especially if it’s a big one. I also love fishing, but I only did it twice and am looking forward to doing it again. 

Some people like me who love catching a fish in the river usually eat the fish they caught. But is it safe? Yeah, I know most of our rivers are polluted. This is why you have second thoughts if you will eat the fish you caught or not.

Are river fish safe to eat? Yes and no. River fish can be safe to eat if the river is clean and has no sort of plastics. No, if the river is dirty and polluted. However, fish won’t survive polluted rivers so don’t worry. If you found no fish in the river, it means that the river is polluted or your boat is in the wrong location. 

River fish is good food, especially for people who love to eat fish. They are low-calorie, and they are rich in protein. River fish that have been caught in rivers that are polluted may contain chemicals that can be bad for your health. So make sure to check the river before catching a fish. 

How Do Fish Get In Rivers?

Most fish can only be found in saltwater ecosystems like the ocean and sea. Also, most of the fishes you found in a river are from the oceans. Now you are wondering, how do fishes get into rivers? 

The whole body of water on Earth is connected. Fishes from the ocean drift to the river. After they have drifted, they adapt to their new ecosystem. That is why there are fishes from saltwater that are now living in freshwater, like rivers. That is how fishes get in rivers!

Salmons are fishes that can live in both freshwater and saltwater ecosystems. They go to the freshwater to hatch eggs and mate, then they go back to saltwater again to survive. Anadromous fish species are the types of fish that spend their lives living in both freshwater and saltwater. 

Final Words

There are many fishes in the world, and that is why many people, including me, promote to people that we should take care of the body of water on our planet. God gave us the authority and responsibility to take care of our planet, so we should do our best to keep it clean and safe to all living organisms.