Fish Facts For Kids | Interesting Facts about Fish For Kids

What is Fish?

Fish is the collective name given to the diverse groups of aquatic vertebrates in the world, that are not only found in freshwater but also in all the coastal waters in each continent. Fish play a significant role in aquatic habitats and many other species depend on it for their survival. A fish is basically a cold-blooded vertebrate which have a backbone along with the fins and gills and lives in water. These three characteristic features (i.e. backbone, gills, and fins) are necessary in order to classify any species a ‘Fish.’ Sharks are classified as fish but jellyfish and starfish cannot be so classified since they do not have backbone and are therefore invertebrates. Similarly, whales and dolphins may seem like a fish but they are mammals because they do not have gills and have mammary glands. Now let us dive deep to learn some of the most fascinating fish facts for kids such as fish diet, fish habitat, fish reproduction, and its distribution.

Fish vary to a great deal in size and color—ranging from tiny species measuring no more than one-half-inch to a huge whale shark reaching a length of 50 feet.

Fish also varies significantly according to the variety of habitats—some lives in saltwater whereas others in freshwater, some in shallow waters others in deep waters, still some survives in cold water against warm water, and still water against fast flowing water. The fish habitats vary according to the temperature, pH, oxygen content, salinity, light level, and physical features, but also differ considerably in the space available. Some species are almost entirely restricted to their native range. The desert pupfishes, for instance, are native to the isolated spring systems of desert regions throughout Mexico and southwest USA with the total populations of 15 – 20 species.

As far as food is concerned, many species rely on aquatic plants while others are predatory species and they actively chase their prey. There are several fish which are found in schools as compared to those living solitary lives. Despite all these differences, they do share some of the common behavioral, physical, and reproductive traits. Many of these species are shielded with scales and are cold-blooded.

Fish Facts For Kids

Fish are divided into three fundamental groups—bony fishes, cartilaginous fishes, and lobe-finned fishes.

The cartilaginous fish includes those species which lacks bony structure and their bodies are tough and flexible enough to adjust with the increasing size. The fish belongs to this group are sharks, chimeras, skates, and rays.

The Lobe-finned Fishes are a group of fish which have a bony skeleton and includes more than 23,000 species among which tarpon, cavefish, lanternfish, salmon, herrings, salmon, electric eels, and cods are most notable. They are thought to have evolved from first four-legged land vertebrates (tetrapods).

When Did Fishes Evolve?

Fish has been constantly seemed to evolve from the time they first appeared. However, the prime evolution occurred in between 500 – 350 million years ago in the Devonian and Silurian epoch, and still they are evolving. Many of fish types seem to emerged in the Devonian period which is they it is also called the ‘Age of Fishes.’ Ostracoderms were thought to be the first fishes and of course the first vertebrates which lived in the Cambrian period some 510 mya (million years ago) but they became extinct around 350 mya.

How are Fishes Classified?

Fishes are by far the most diverse groups as compared to many vertebrates and other species. One can find a good many number of fishes in just two acres of pacific reef as compared to the number of bird species throughout North America. Fishes are classified into different classes being based on central anatomic differences.

Superclass Agnatha: these types of fish have a cartilage skeleton and give a primitive fish-like appearance, lacking jaws. The examples are eel-like lampreys and hagfishes.

Class Chondrichthyes: these fishes have jaws and their skeleton is made up of cartilage and not of bone. There are around one thousand species of this class and the most notable amongst these are skates, sharks, and rays.

Class Osteichthyes: the bony fish is the most diverse and contains the bulk of extant fishes today. This class is further subdivided into subclasses or orders.

Elopiformes—tarpons and bonefish

Salmoniformes—salmon, smelts, trout pikes

Cypriniformes—carps, minnows

Anguilliformes—true eels

Clupeiformes—anchovies, herrings

Gadiformes—haddock, cod, whiting


Beloniformes—needlefishes and flyingfishes


Perciformes—cardinalfishes, basses, angelfishes, pipefish, sunfish, cichlids, jacks, sticklebacks, barracuda, blennies, drums, wrasses, grunts, tuna, mackerel, seahorse, perch, gobies, tuna, gouramis, goatfishes, parrotfish

Cyprinodontiformes—topminnows, mollies, guppies, killifishes

Lophiiformes—frogfishes, anglerfishes

Pleuronectiformes—flouders, soles (flatfishes)

Scorpaenformes—rockfishes, stonefishes, scorpionfishes, searobins

Tetraodontiformes—triggerfishes, ocean sunfish, filefishes, puffers, boxfishes

 fish facts for kids
Salmon Fish

How many Species of Fishes Exist Today?

Even though more and more fishes are being discovered with the passage of time and scientists are still not sure precisely as to how many species of fish really exist on planet, scientists have identified more than twenty-five thousand species of fish. Many species are deemed to be discovered in the sea as it is easy to explore in it than in deep-sea waters.

How Long Do Fishes Live? | Fish Facts For Kids

The lifespan of fish varies considerably from few days to several years. Generally small fish live no more than a year while the large ones can live for decades. One such species is Sturgeons which is one of the longest-lived fish species with a lifespan of 50 years. Some species can live a fairly long life if it is given proper care in captivity. An Australian lungfish (Neoceratodus forsteri), for instance, is more than 80 years old and is still alive in Chicago’s Shedd Aquarium. Similarly, different kinds of common carp are kept in captivity and they live around 65 – 70 years. One of the longest lived species died in the Japanese family and it lived for 276 years as it was deemed to pass down by generations, a koi seller reported. A coral reef pygmy goby (Eviota sigillata) is the shortest known fish species which live for a month or two.

Read More: Do Polar Bears Eat Fish?

How can you Determine the Age of a fish?

Thanks to the cycloid and ctenoid scales on a bony fish which grows with the age of a fish because of this we can precisely determine its age. The scale releases concentric circular bands known as circuli, with its growth. The larger the space between circuli the more favorable the environmental conditions (abundant food and fast growth) is for a species. The space becomes smaller in times of decreased metabolisms or environmental depression which is usually occurred in winter when the growth is slow. Sometimes the circuli gets closer so much so that they seem to appear a single line.

Interesting Fish Facts For Kids

Fish are cold-blooded animals which mean they maintain internal body temperature with respect to the surrounding. Fish occupies almost all the major waters ranging from the deepest sea trenches, oceans, to the high mountain lakes, streams, ponds, rivers, and marshes. Some are adept to survive in icy cold water such as icy fish which is only found in icy Antarctic sea. It contains special antifreeze which prevents its blood from freezing.

Have you ever wondered what is the Smallest Fish in the world?

The smallest fish discovered so far is a Goby Trimmatom Nanus from the Indian and Eastern Pacific oceans. It measured less than 10 millimeter in length.

What is the most Common Fish?

Cyclothone Microdon is the most common and widely distributed fish in all the oceanic waters of the world, but are absent from the poles. It won’t be an exaggeration if I say that it is the most widespread vertebrate living on earth, with populations of billions.

What is the most Rare Fish?

The Devil’s Hole Pupfish is one of the rarest species found only in one pool in the Nevada Desert. The pool measured around 18 m in length, 3 m in width, while 90 m in depth. It lives in the shallow rock ledge with the total population comprising no more than 800 individuals.

What is the Longest-lived Fish?

Lake Sturgeon is one of the longest-lived fish species with an average lifespan of 70 – 80 years. According to an unknown claim one species might have lived up to 145 years but this is not confirmed yet. Scientists aren’t sure exactly as to how long do sharks live but some species are known to live that much longer (above 70 years). Besides, sharks, carp are also some of the longest-lived species with the lifespan of 50 years. It is thought that some carps in captivity lived up to 260 years.

Which Fish is called ‘Annuals’, and Why?

Most of the killifish species are called ‘Annuals’ as they survive in pools which become dry for part of the year. They live but seasonally and consume almost all the insects which are present in the seasonal pools. The eggs hatch in the wet season when pools are full of water. The juveniles grow quickly and spawn after couple of months. Once the pool is dry, all mature fish dies out, but eggs survive the drought to hatch next wet season.

Were Fish the First Animals to have Evolved Backbones?

Yes, fish are the first animals to have evolved backbones with the earliest known species which became extinct some 520 million years ago, was Ostracoderms, that emerged in the Cambrian Period. These primitive species lacked jaw bones and teeth but they certainly had notochord.

What is the Largest Group of Fishes?

With more than 24,000 species accredited to this group, ray-finned fishes is arguably the largest group of fish. These species are divided into 431 families.

Do Fish create a Wave Motion while Moving?

Yes, they do indeed! It so happens that while moving it generates a wave motion which facilitates the length of its body and this wave begins at the head and goes to the end of tail where subsequent side-to-side movement generates thrust to redeploy the fish through water.

Are there Any Jawless Fishes Alive Today?

There are only two groups of jawless fishes alive today: hagfish and lampreys.

Are there any Predatory Fishes Today?

Yes, there are some species that are classified as predatory fish since they actively prey on live aquatic animals and sometimes attack humans too. Atlantic Sturgeon, for example, is a predatory fish which is often found inuring boaters when they dive. It is now protected as it is endangered. Similarly, Alligator Gar is another species that seems like it could eat you. It is one of the North American biggest fish species.

What is the Most Common Fish in United States?

Bluegill is the most widespread fish distributed throughout the United States.

What is the name of the world’s Deepest Living Fish?

Abyssobrotula galatheae is the world’s deepest living and it lives in the Puerto Rican Trench at a depth measuring at 8372 meters. the Tibetan stoneloach (Triplophysa stoliczkai) is found at an altitude of 5200 meters in the Himalaya.

Warm-water Fishes | Fish Habitats | Where Do Fishes Live

It would be correct to say that more than eighty percent of all fish species in shallow seas live in temperate and tropical waters, many closely linked to the coral reefs and atolls. In these waters, the temperature does not drop below 18 degree Celsius even in coldest days. Coral reefs are widely distributed throughout western and Indian Pacific oceans, with some species exist around the West Indies and Caribbean. The total population of coral reefs is unequally distributed among the Pacific reefs of New Guinea and Philippine. The Florida is home to 500 – 750 extant species.

Almost all coral fishes are acanthopterygians, and numerous families including wrasses (Labridae), butterfly fishes (Chaetodontidae), gobies (Gobiidae), damsel fishes (Pomacentridae), and squirrel fishes (Holocentridae) stand for coral reefs worldwide.

Which Species are greater in number—Freshwater species or Saltwater species?

The seawater is ten thousand times more in comparison to the freshwater but still two out of every five species exist in freshwater probably due to the varied habitats and because the freshwater species can simply be isolated, by alteration in water level, for instance…once the water level of a lake descends, the entire population is isolated into two new bodies of water. The then separated population began to live differently because of the changing habitat conditions in two lakes—long separation can at times lead to distinct species so much so that it becomes difficult for them to interbred again—they turned out to be new species altogether.

Fish that Migrate

A good many number of fish species fancy their life either in saltwater or in freshwater only, and they do not migrate. There are some, however, which do migrate such as Atlantic Salmon and European Eel.

  • Atlantic Salmon
    Salmon nest and spawn in rivers and move to sea water for feeding. After eggs being hatched, the young fish stay in rivers consuming invertebrates only for about 2 – 4 years. This kind of lifestyle is known as anadromous. They began to migrate towards sea after reaching a length of 15 cm. While in sea, the immature salmons rely on shrimps and small fish for daily consumption. These young ones will grow rapidly. After a period of one or four years, they move to the river for spawning.
  • European Eels
    European Eels are known to spawn in Sargasso Sea after which it moves to the waters of North Africa and Europe. The elongated-body species is adapted for dwelling and burrowing in cracks. They mostly travel via underground streams and by traveling this way they often end up in ponds with no apparent direct connection to the sea. The species which spawn at sea but migrate to freshwater are known as catadromous. The females have a lifespan of 20 years while males live up to 6 years or so.

Freshwater Fish Facts For Kids

Freshwater species embraces all the fish species that are used to living in non-saltish water habitats. Several different freshwater habitats are found throughout North America such as rivers, marshes, ponds, springs, canals, streams, and lakes. Each of these North American habitats offers a unique living environment and each one of these is occupied by fish which are modified to the conditions found there. All these habitats have little or no salt content except the Great Salt Lake and the Great Basin area of Utah and Nevada which are high in salt content. Some of the fish species, however, are not adapted to the wide range of water environments and they do not tolerate even slight changes in living conditions.

It goes without saying that each fish presents a unique display in its size and shape, but the structure is almost entirely the same in all species. Fish undertakes respiration as the water having dissolved oxygen goes through the gills of a fish. The leftover (waste) is secreted through the gill tissue to the surrounding water.

1.)  Catfish

Bullhead is the largest family of catfish. The waters of Mexico and Canada are home to 45 catfish species out of which some can even walk on land which is why they are called walking catfish. These catfish walk on their fins during rain. It is an exotic species and is found only in Florida.

2.) Bullhead Fish

Bullhead catfish displays four pairs of barbels, which are also known as whiskers and feelers, circling their mouths. Barbels are basically organs that facilitate the fish in identifying the food and also it offers the fish a sense of touch.

Bullhead fish is also composed of adipose fins that accumulate fat and pelvic fins that match with the back limbs of terrestrial vertebrates. Some species, especially North American catfish, have robust skins lacking scales on their bodies. They employ their pointed spines as weapons and also that in certain cases, these spines are somewhat poisonous. One such species is Madtom catfish which is claimed to have this kind of poisonous spines to injure opponents.

3.) Black Bullhead (Ameiurus melas)

The black bullhead fish reaches a length of 24 inches. It shows greenish-gold coloring on the sides, while on the back it makes up olive to yellowish brown that fades away as we move to the side. Black bullhead fish build its habitat in lakes, ponds, pools, and sluggish rivers. It is endemic to the waters of United States ranging from Great Lakes to Mexico through some other regions have introduced this species from time to time. Brown and yellow bullhead belong to the same family.

4.) Channel Catfish (Ictalurus Punctatus)

The channel catfish is characterized by its little dark spots on its side and back in the midst of greenish-black coloring. It has white undersides. It can grow to a length of 50 inches and is found in deep lakes and rivers. Presently, many of the species live in the United States. Being scavenger by nature, channel catfish primarily relies on animal matter. Catfish are native to warm waters since they bear higher water temperatures as compared to many other species. They are almost entirely nocturnal bottom feeders. Several other catfish species exist in North America and they differ significantly in shape and sizes. Some species are as small as 1½ inches such as pygmy madtom while others are as long as 5 feet like flathead catfish. Only one North American species is included in a second catfish family and it is known as walking catfish. Authorities have introduced it in the waters of California though it is abundant in Florida waters. It can breathe since a small part of gill acts like a lung tissue. It is known to employ pectoral fins and tail to propel itself over the ground surface.

5.) Sunfish

Sunfish are endemic to North America and it is associated with the family of Centrarchidae. Crappies, bluegills, and basses also come under the same family. Sunfish remains active all throughout the day and it becomes inactive as the day passes on. As the name indicates, it prefers to move under the sunlight.

6.) Largemouth Bass (Micropterus salmoides)

The largemouth bass fish is native to the waters of United States and Canada and is also a popular game fish across North America. Some of these species have been introduced to few other regions in the recent times.

The largemouth bass is known to build its habitat in deep pools, lakes, ponds, sloughs, rivers and in streams. It likes to live in water being dominated by plants. Being predatory by nature, largemouth bass preys on aquatic animals.

In the Centrarchidae family, males build the nest in which females lay eggs. It creates a narrow depression in the sand or stream or at the bottom of a lake. The male also guards the nest and its offspring within its vicinity.

7.) Smallmouth Bass (Micropterus dolomieu)

The smallmouth bass happens to be brownish olive on the back and speckled with dark patterns. Its underparts are entirely yellow and it displays dark bars spotted on yellowish green colored sides. The population is not limited to its native range rather it ranges from central United States to the southern Canada. It prefers to build habitats in rivers, lakes, streams that are accompanied with rocks and gravel bottoms. The flowing water in the shallow lakes is what actually defines its ideal habitat. It eats aquatic animals and small fish.

8.) Black Crappie (Pomoxis nigromaculatus)

The black crappie is a small fish with a compressed body characterized by its greyish-green back. It has silvery-blue sides which, together with black lines, leave a seemingly striking appearance. The underparts are white. Black crappie fancy living in slow-moving clean and calm waters and it is found in deep waters. Its habitats are found in sloughs, lowland ponds, and lakes. Black crappie is a native species to the eastern United States.

9.) Bluegill (Lepomis macrohirus)

Bluegill is one of the most widespread in the waters of freshwater lakes and ponds. It is also native to the eastern United States but is commonly found in the southern states ranging from Mexico to Canada. Most of its habitats exist in swamps, pools, ponds, and lakes where vegetation is plentiful. Bluegill predominantly feeds on small invertebrates especially worms, zooplankton, and insects.

10.) Perch

Perch belongs to the family of Percidae and is commonly found in North America. It stands the second highest number of species among North American fish families. Darters (small fish) are the most widespread in numbers. There are around 150 species of bottom-dwelling fish.

11.) Yellow Perch (Perca flavescens)

A large-mouth yellow perch exhibits a deep beaten body together with a greenish brown back and yellow undersides. Atlantic drainages are home to these fishes ranging from Central Canada to northeastern United States. Like catfish, it is also not limited to its native range. It is found in deep waters of rivers and streams. Perch prefers to stay in water where vegetation is abundant. It feeds heavily on aquatic animals and insects. It reaches a length of 16 inches.

12.) Walleye (Stizostedion vitreum)

The large-mouth walleye reaches a length of 36 inches is characterized by yellowish brown at the back together with yellowish-blue undersides that are stained with dark green makings.

Walleye likes to survive in fairly clean water with brushy banks and it inhabits lakes, ponds, and rivers. The juveniles primarily rely on small insects while adults feed heavily on minnows. These species are endemic to central United States and Canada.

13.) Trout, Char, and Whitefish

All the fish in this group are associated with the family of Salmonidae. Besides freshwater species, there are few salmonids that are known to travel widely to the ocean.

14.) Brown Trout (Salmo trutta)

One of the striking and brightly colored fish, brown trout portrays a silvery yellowish-brown undersides and an olive-brown back. Its sides and back are marked with black and red spots, with few fins being reddish orange. The make brown trout has curved lower jaws.

They keen to live in cold waters of river, stream, and lakes. They prey on small fish, mostly insects, frogs, and numerous other aquatic animals. Originally found in Europe, they were brought in North America in 1883. Presently, brown trout is widely distributed all throughout Canada and United States. They require aerated water and cool temperatures, containing higher content of dissolved oxygen. It builds its habitat in fast-flowing water in deep pools and streams.

15.) Rainbow Trout (salmo gairdneri)

The rainbow trout varies in appearance and color from one habitat to another. The species residing in lakes have predominantly silvery look while those living in streams have yellowish-green back and silvery sheens on their sides.

The pacific drainage is home to rainbow trout and is abundant in lakes, water streams, and rivers in the region. Rainbow trout also survives in isolated streams in some areas. It is considered as one of the most important fish throughout North America. It feeds on insects, small fish, small aquatic animals, and worms. The female releases her eggs in the gravel streambeds and shallow scrapes.

Many species of Salmonidae family move towards spawning waters. Those surviving in ponds and lakes migrate to the flowing streams from calm water which is the freshwater sources. They accomplish reproduction in gravel beds in which well-aerated water is abundant and their eggs are trapped in the rocks. Once the spawning finishes, these species move back to the lakes. Those residing in rivers often move towards small streams that fall into the river.

16.) Mountain Whitefish (Prosopium williamsoni)

A small-mouth mountain whitefish happens to be greenish brown on its top while its undersides are silvery in color. It reaches a length of 22.5 inches and is found in cold water habitat such as in streams and lakes. The population is equally distributed between United States and Canada. They form a large group known as schools. It relies on small insects, worms, and small aquatic animals for their consumption. The female lays eggs in the gravel bottoms and sand of streams and rivers.

Brook trout and closely associated fish are called chars. With the arrival of spawning season, they become brightly-colored with some species display red coloring on their sides and fins.

17.) Brook Trout (Salvelinus fontinalis)

The brook trout is a permanent resident of eastern United States but now it has been introduced in the Pacific Drainage. They are found in flowing waters of streams and creeks. It mainly consumes insects and other aquatic animals. The males become brightly-colored in the spawning season with some red and pink marks on their sides.

18.) Arctic Grayling (Thymallus arcticus)

Arctic Grayling is a resident of Pacific, Arctic, and upper Missouri river drainages throughout North America. It is not limited to its native range in western United States. The dorsal fin of these species is marked by red and green spots. It has a small mouth in which there are small teeth. It has a forked tail and is sheltered by rather blue-gray scales on the upper body. It is found in cold waters of large rivers.

19.) Pike

Pike is associated with the family of Esocidae. They are active predators and they also devour fish almost the same size as that of their own. With the help of long jaws, they can simply swallow the entire prey. Pikes are cannibalistic feeders.

20.) Northern Pike (Esox Lucius)

A huge-mouth fish, northern pike reaches a length of 6 feet. These fish finds its habitat in lakes, ponds, rivers, marshes, and pools, which are abundant in vegetation. They hide themselves behind the bushes in order to stalk their prey as they feed on aquatic animals. Northern pike is widely distributed in continental United States and occupied much of the range of Canada and Alaska.

21.) Sturgeons

Sturgeons stand the largest fish species throughout North America. It grows to a length of 20 feet and it lives in large waters. Sturgeons being a member of Acipenseridae family are one of the longest-lived fish with an average life span of 75 years. They disturb the mud at the bottom to find out any food.

22.) Shovelnose Sturgeon (Scaphirhynchus platorynchus)

The shovelnose sturgeon is characterized by its shovel-shaped snout and it has a sharklike tail. It has four barbels which help it to find food. It preys on aquatic animals which are at the bottom of the river or sometimes beneath the mud. There are large bony plates known as scutes which offer shelter to its back, head, and sides. It finds its habitat at the bottom of the flowing water. It is found in Mobile Bay, Rio Grande, Mississippi drainages.

23.) Minnows and Suckers

The minnows exist in every continent, occupying all the major waters, with the largest concentration is found in the north of Mexico. It is a false belief that minnows are small fish. Some of these species are as large as 49 inches. It belongs to the Cyprinidae family which also includes squawfish, chubs, carp, goldfish, shiners, and several other species.

24.) Common Carp (Cyprinus carpio)

The common carp has an elongated compressed body with a fairly leveled belly. It reaches a length of 48 inches and is bright metallic green in appearance. It makes its way in slow-moving waters having organic matter. The common carp consumes plants matter but it also feeds on aquatic organisms. Its habitats are found in rivers, lakes, and ponds in the southern Canada and United States. Some of these species are almost wholly vegetarians and they consume many aquatic plants.

25.) White Sucker (Catostomus commersoni)

The white sucker is portrayed as a black to olive brown on the sides and on its back, with light undersides. It feeds on heavily on aquatic organisms and plants matter especially at the bottom of ponds, lakes, and rivers. Its habitats vary from small creeks to large lakes and it grows to a length of 25 inches. Sometimes these species are regarded as trash fish, for they are not very effective human food. As a result, its population keeps on increasing.

26.) Salmon Fish

Salmon is associated with the family of Salmonidae. They are closely related to the freshwater species of whitefish and trout. They are known to live in rivers and coastal waters of Pacific and Atlantic coasts of North America. These species often migrate toward the ocean where they live and grow to become adults. Once they become adults, they retreat back to the rivers to reproduce the next generation.

27.) Atlantic Salmon (Salmo salar)

The Atlantic salmon is a long, streamlined species measuring around 55 inches in length. It displays greenish, blue, or brown coloring on its back while the sides are almost entirely silver. These colors appear to be darker as the fish enters into freshwater, and as the spawning accomplishes, red spots begin to appear on its body. They are usually found in Atlantic coast where they feed on marine animals including shrimp. With the arrival of spawning season, Atlantic salmon begins to live in coastal waters of rivers and streams. The juveniles, before finally entering into the ocean, live in freshwater for 2 to 3 years. They, however, migrate back to rivers for spawning after spending a year or more in the ocean. Once the spawning is finished these fish again return to the ocean. Atlantic salmon are some of those species that are capable of spawning more than one time.

28.) Chinook or King Salmon (Oncorhynchus tshawytscha)

True to its name, king salmon is the largest salmon with the weight averages 30 – 50 pounds, though some are even heavier. It display two to three colors ranging from green, blue, to gray out of which the gray is dominant and the back is marked with few black spots. The reddish sides and silvery undersides make it identifiable among the rest. The king salmon feeds heavily on shrimp, fish, and other aquatic organisms. It lives in the Pacific and Arctic Ocean in the North America with some species are stocked in Great Lakes. It is the rarest in the Pacific salmon fish. It retreats to the river for spawning after which it dies out soon.

29.) Pink Salmon (Oncorhynchus gorbuscha)

The pink salmon is characterized by its metallic blue to bluish green appearance together with black spots on the caudal fin and on the back. The males display brownish-pink stripe down their sides. It reaches a length of 30 inches with its undersides are silver. The males have humped backs and hooked upper jaws. The pink salmon lives in the coastal and stream habitats ranging from California to the arctic region. It feeds on shrimp, fish, and other aquatic animals.

30.) Sockeye Salmon (Oncorhynchus nerka)

The sockeye salmon is the best known salmon among the Pacific species. It lives almost entirely into the ocean. It displays silvery appearance together with small black spots. It migrates to freshwater for spawning and becomes reddish in appearance as it enters into it. The males have evolved hooked jaws and large teeth. Once the hatching is done, the fish moves to the downstream lake where it lives for 3 years before finally migrating to the ocean. Many of these species retreat to the home rivers to spawn when they are 5 years of age. Those living in far northern waters often wait to return until they are 7 – 8 years of age. Some sockeye species do not often travel far from the oceanic water whereas others cover hundreds of miles inland to their home waters. The sockeye is native to the waters of Pacific and rivers.

31.) Coho Salmon (Oncorhynchus kisutch)

A silver-colored fish, coho salmon is characterized by its black markings and metallic blue back. Both males and females evolve reddish side, a bright green back, and hooked jaws. They usually stay 2 years in ocean during which their diet varies considerably. While the young salmon rely on crab larvae, insects, lance copepods (crustaceans) and herring in the first year, adults feed on sand lance, large zooplankton, squid, and herring in the subsequent year.

Prior to migrate toward ocean as smolts, these species remain in coastal streams for a period of 2 years. Only a handful number of salmon venture far out to sea since many of them stay close to the coast. The largest concentration of coho salmon lies in the Cook Islands in southern Alaska and in the waters of Columbia River. They are also found in the Pacific coast ranging from California to Alaska.

Saltwater Fish Facts For Kids

Saltwater fish and fauna embrace all those creatures that primarily dwell in oceans and estuaries. Their characteristic features are perfectly adapted for living salty environments. Unlike freshwater environments, oceans are abundant in nutrients; as a result many aquatic animals can easily find rich supply of food.

A marine biome contains the least content of salt averaging 3 – 3.7 percent. Oceans occupy most of the earth’s surface averages 71% in total; since they are interconnected with one another, oceanic organisms can migrate easily from one ocean to another. Each ocean has its own environmental conditions which indeed defines the habitats of many marine organisms. Water temperature, for example, is different in arctic regions than in southern regions. Similarly, the shallow waters have much less temperature as compared to that in deep-sea-waters. Likewise, food supply also varies considerably as we move from shallow waters to several hundred-feet-depths precisely due to the lack of penetration of sunlight into the deeper strata. These differences affect numerous kinds of saltwater fish and fauna.


Sharks, Skates, and Rays

The sharks and rays belong to a classification known as cartilaginous fish. These fish have robust skeletons which are not made of bones but of a tough elastic tissue which allow them to move freely. Sharks are medium-sized species with the exception of whale shark which is the largest fish in the world with the length measuring at 60 feet. It feeds on planktons which it sieves out of the seawater, along with crustaceans and small fish.

1.)  Whale Shark (Rhincodon typus)

The whale shark is the world’s largest fish with the length averaging 18 meters, and it has hooked teeth and broad head which makes it stand among the rest. It is characterized by reddish or greenish brown appearance with the dominance of gray color which is marked by light-colored dots on its upper body. The belly is white or yellow.

Whale shark marks its territory in the warm waters of Atlantic and Pacific coasts and in the Gulf of Mexico. It primarily preys on plankton which it gathers near the water surface.

Perhaps the most feared fish to humans are sharks. This is because some sharks are predatory species as they actively chase their prey even though they seldom attack humans. They have several layers of teeth in the upper and lower jaw which are soon replaced with the new ones when they break or fall out.

2.) White Shark (Carcharodon carcharias)

The white shark is a large species that actively preys on many aquatic organisms such as sea lions, turtles, birds, other sharks, shellfish, seals, and other kinds of fish. It measures around 30 feet, with the grayish-black back and white undersides. Its teeth are large and triangular in shape and have serrated edges. White sharks are found in moderate to tropical waters of North American coasts. Sharks vary in size ranging from couple of feet up to 60 feet.

3.)  Sand Tiger Shark (Carcharias Taurus)

Sand tiger shark is native to the Atlantic coast and it belongs to the Carchariidae family. It prefers to stay in shallow waters ranging from Maine to Florida and exists on both sides of Atlantic Ocean. It is light-colored shark and its skin is marked by several bright spots on its sides.

Rays and skates are streamlined by long thin tails, flattened bodies, and huge wing-like pectoral fins. They also have strong skeletons being made of hardened cartilage. They live in the North American coastal waters ranging from Pacific to Atlantic Oceans. They rely on shellfish for consumption.

Some rays are skates are very unfamiliar in their characteristics. One such example is stingray (Dasyatidae family) which has a deadly poisonous spine on its tail and it uses it against potential predators. Similarly, electric rays (Torpedinidae family) are known to discharge electric shock enough to kill its enemies.

4.) Pacific Electric Ray (Torpedo californica)

The Pacific electric ray, also referred to as torpedo, is a smooth skinned species and it seems like a disc floating in the water. It exhibits several shades of gray from upper body while its underparts are light-colored. The females are large than males with the length averaging 4½ feet and weigh around 90 pounds. It uses its best defense which is electric shock and that paralyzes its prey. It feeds on shellfish, halibut, herring, and other fish.

Mackerel, Tuna, Marlins

Mackerel, tuna, and marlins are large species and are also very fast swimmers. They come to the surface for feeding and are mostly travel in large schools. They believe in hunting in groups.

5.) Chub Mackerel (Scomber japonicas)

The chub mackerel has an unmistakable appearance of several vertical stripes on its sides with its upper body is blue or green, and silvery underparts. It is smaller than tuna. The adults reach up to 16 – 18 inches in length. It is pelagic species which means that it lives in open ocean. The chub mackerel consumes crustaceans, plankton, and also fish. It is found in greater number in Pacific Ocean ranging from Alaska to Mexico, and it generally dwells in moderate oceanic waters in different parts of the world. It is also called Pacific Mackerel probably due to its abundance in Pacific region.

Mackerel and tuna are associated with the family of Scombridae. Both these species cover temperate and tropical waters, and they exist in both offshore and inshore. They are migratory fish as they travel south in the winter north in the summer. The tuna primarily feeds on crustaceans, plankton, and other fish.

6.) Albacore (Thunnus alalunga)

The albacore is abundant in the Pacific Ocean with some species also exist in Atlantic Ocean. It is also migratory species as it lives in pelagic habitats. It likes to survive in warm waters of tropical and subtropical regions. Its upper body exhibits dark blue color with the underparts being silvery white, and they have long pectoral fins. It reaches a length of 4½ and weigh up to 75 – 80 pounds. A group of fish that belong to the mackerel and tuna form Istiophoridae family.

7.) Blue Marlin (Makaira nigricans)

The blue marlin is a relatively large fish with the length averaging 11 feet. Many of these species weigh up to 1,800 pounds. It has a demarcation line which separates the brown to dark blue top from a silvery white underneath. It has vertical bars on its sides.

Blue marlin lives in the Atlantic and Pacific Oceans. The Atlantic species are much smaller in comparison to the Pacific specimens. It is known to consume other fish such as frigate mackerel, blackfin tuna, squid, and other pelagic fish. It is a fast swimmer with the speed reaching 50 miles per hour. With the help of its large hooked bill, it strikes its prey. Little is known about the reproduction of blue marlin.

Flounder, Halibut, and Sole

These fish are the members of the order flatfish (Heterosomata). It prefers to stay for the most part of its life in ocean bottoms. Thanks to their flattened bodies due to which they are adapted to the bottom waters, the eyes being located on the upper side of the head.

8.) Dover Sole (Microstomus pacificus)

The flatfish Dover sole is one of the most delicious and flavored dish for humans. It ranges from the Pacific waters of Alaska to Mexico. It stays mostly in continental shelf and only move towards deep ocean for spawning. It has an eye only on the right side and is blind from the left. The dover sole has a brownish upper side and gray blind side. It reaches a length of 12 inches. They are bottom-feeders.

9.) Pacific Sanddab (Citharichthys sordidus)

The Pacific Sanddab is a left-eyed species and is characterized by a dark brown to mottled brown appearance with some individuals have yellow or orange markings. They live in the waters of Alaska to Mexico and are popular food fish. They are also known to bury themselves in the ocean floor, exposing only eyes. They eat small fish and crustaceans.

Flatfish carnivorous species and they feed on bottom-dwelling aquatic animals including crustaceans, squids, and other fish. Some of the predatory fish do prey on flatfish but these fish are not always easy to prey because of their camouflaging ability. They often change their color to mix with the color of the seabed.

10.) Atlantic Halibut (Hippoglossus hippoglossus)
Pacific Halibut (hippoglossus stenolepis)

The Atlantic and Pacific Halibut are large right-eyed fish with the length measuring at 8 feet and weigh up to 400 pounds. The Atlantic halibut has longer lifespan as compared to the Pacific halibut and the former is also greater in size. Both these species are flattened shape. They have both eyes on the same side. Unlike other flatfish, the halibut has a normal-shaped mouth. The young halibut consumes plankton in the first year. The adults eat small shrimp, herring, clams, crabs, octopus, smaller halibut, small fish, and other marine organisms. It can sustain in temperate and cold waters.

11.) Pacific Herring (Clupea pallasi) and Atlantic Herring (Clupea harengus)

The Pacific and Atlantic herring is characterized by its olive and bluish green top together with silver-colored underparts, and hooked tail. It has an average length of 12 inches and billions of them are preyed upon by humans each year. They feed on plankton which they obtain from the ocean surface.

Herring are also called demersal spawners since they ascribe their eggs to weeds and other materials on the ocean floor. Some of the most notable herring species are the North American skipjack which lives in the freshwater habitats ranging from Gulf of Mexico, Mississippi River, to the eastern tributaries. The alewife occupies the waters from Atlantic coast, Newfoundland to the North Carolina.

12.) Atlantic Codfish (Gadus morhua)

The Atlantic codfish is a small fish with the weight measuring at 10 – 12 pounds. Even the heaviest of these species do not exceed 60 pounds in weight. A long fish, display an olive green to brown façade which is dominated by dark brown markings. It has a single barbell under its chin that is employed as a feeler. This species is abundant all throughout the North Atlantic Ocean probably due to its fast growth. It can become 15 inches long at 2 years of age. They tend to move towards south in the winter season for spawning, which begins at the age of 5. The adult females lay up to 5 million eggs out of which only few reach adulthood.

13.) Pacific Codfish (Gadus macrocephalus)

The Pacific Codfish has a gray to brown upper body with the brown markings on its side and back and light-colored barbels. Gray Cod is the other name of this fish. Its range is found in the cold waters of the Pacific Ocean from Alaska to California. It seldom exceeds 35 – 40 inches in length. The haddock is closely related to the Pacific codfish and both these species share many areas together.

14.) Snowy Grouper (Epinephelus niveatus)

The snowy grouper offers a light brown exterior which is marked by white spots. It has a large mouth. It is found in the warm temperate waters of the Atlantic Ocean. Snowy groupers breathe in rocky ocean bottoms and they consume crustaceans, fish cephalopods, and gastropods. It measures around 4 feet in the Atlantic Ocean, while those living in the Pacific are smaller (measuring 31 inches in length).

15.) Spotted Sand Bass (Paralabrax maculatofasciatus)

The spotted sand bass inhabits southern California and Gulf of California and is a bottom-dwelling species lives at a depth of 200 feet. It can withstand in a varied water temperature. It can survive in temperature as low as 45 degrees and as high as 90 degrees Fahrenheit. It inhabits bays and harbors. The olive-colored upper body and light-colored underparts is what explains the spotted sand bass’ outlook.

Bass are the opportunistic feeders and they remain inactive most of the time. Numerous factors define the feeding drive of bass such as competitive greed, vulnerability force, and intake efficiency factor. Bass are capable to stalk and forage their prey even in extreme low light and as a result they are not easy to be identified. Thanks to the mirror-like coloration which makes them almost invisible in deep water.

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