- Wildlife

Are Sharks Mammals? Is A Shark A Mammal Or A Fish?

Sharks should not mammals; sharks are fish. Sharks lack mammalian traits akin to hair and lungs, and don’t produce milk. Being fish, sharks have scales and fins, and breathe utilizing gills. Sharks belong to the category Chondrichthyes, whereas mammals belong to the category Mammalia.

Though sharks do share some bodily traits with mammals (particularly marine mammals akin to whales and dolphins), they’re very various kinds of animal.

On this web page you’ll uncover why sharks are fish reasonably than mammals, and be taught some wonderful info about each teams of animals alongside the best way…

Is A Shark A Mammal?

Is A Shark A Mammal

A shark shouldn’t be a mammal, it’s a fish. Though there are some similarities between giant shark species and aquatic mammals akin to whales, the 2 teams of animals are not associated and belong to thoroughly completely different courses. A shark is a member of the category Chondrichthyes (one among three courses of fish); a mammal is a member of the category Mammalia.

Variations Between Sharks and Fish

  • Sharks “breathe” with gills.
  • Mammals breathe with lungs.
  • A shark has scales (mammals don’t)
  • Sharks lack mammalian traits akin to hair, mammary glands (for producing milk), and a neocortex (a part of a mammal’s mind)
  • A shark’s skeleton is product of cartilage.
  • A mammal’s skeleton is product of bone.
  • (Most) sharks are cold-blooded.
  • All mammals are warm-blooded.
  • All of a residing shark’s ancestors are aquatic animals.
  • The ancestors of each residing mammal (even sea mammals akin to whales, dolphins and manatees) embrace animals that lived on land.

Sharks and mammals belong to completely different courses

A category is a gaggle of associated animals; one among a number of completely different teams that biologists use to categorise residing issues.

You could find out extra about animal classification on this web page: Animal Classification

Sharks belong to the category Chondrichthyes, which is one among three courses of residing fish (see under)

Mammals belong to the category Mammalia. There are round 6,025 mammal species. (Supply)

The Three Lessons Of Residing Fish

  • Chondrichthyes (cartilaginous fish): fish akin to sharks, rays and skates
  • Agnatha (jawless fish): fish akin to hagfish and lampreys
  • Osteichthyes (bony fish): fish akin to cod, salmon, carp, bass, eels, and many others.

There are different courses of fish, however they comprise solely extinct species.

The category Chondrichthyes itself is split into two subclasses: Elasmobranchii, which accommodates all sharks, rays, skates and sawfish; and Holocephali, which accommodates fish often called chimaeras, that are primarily deep-sea species.

Shark Species

Types Of Sharks
A small number of the c. 530 shark species. Click on on the picture to see completely different shark species.

There are round 530 completely different species of sharks. Sharks are far outnumbered by the bony fish of sophistication Osteichthyes, of which there are round 28,000 species!

You could find out extra concerning the various kinds of sharks on this web page: Kinds of Sharks with Photos and Info

What Is A Mammal?

Mammals Pictures
Most mammals are land animals, however some (e.g. whales and dolphins) are aquatic, and a few (bats) can fly. Click on on the picture above to see extra mammals.

Mammals are a big group of various animals, all of which have sure traits in widespread.

You could find out extra about mammals on this web page: Mammals: The Final Information

One of many defining traits of mammals is that feminine mammals produce milk for feeding their younger.

The phrase ‘mammal’ comes from the scientific phrase for the mammary gland – the a part of a feminine mammal’s physique that produces milk.

You may see examples of mammals on this web page: Mammals Record with Photos and Info

Sharks don’t feed their younger with milk, and subsequently aren’t mammals.

Different traits that each one mammals share embrace being warm-blooded and having hair (or fur).

Humpback Whale
Even whales have hair (or a minimum of, hair follicles). Click on on the picture to see extra whales.

Being heat blooded implies that an animal is ready to regulate its personal physique temperature (by shivering, and many others.) so as to keep a relentless temperature.

The scientific time period for being warm-blooded is endothermic.

Most sharks are cold-blooded. A typical shark’s physique lacks the means to regulate its personal temperature, and is reliant on exterior circumstances.

The scientific time period for being cold-blooded is ectothermic.

Heat-Blooded Sharks

Shortfin Mako Shark
The shortfin mako shark is among the few sharks which might be warm-blooded. Click on on the picture to see enjoyable info on sharks!

Some sharks within the household Lamnidae (e.g., the nice white shark and the 2 species of mako shark) are warm-blooded, and are capable of preserve the temperature of their our bodies at a unique degree to that of their environment.

Regardless of being warm-blooded, these sharks should not mammals. The method by which they management the temperature of their our bodies is completely different to that present in mammals.

Sharks Vs Whales

Whale Shark
The whale shark is the world’s largest shark. Regardless of its title (and its dimension) it’s not a whale; it’s a fish. Click on on the photograph to find extra about ​whale sharks.

The explanation that so many individuals ask the query “Are sharks mammals?” is that giant sharks such because the nice white shark resemble aquatic mammals akin to whales and dolphins.

The truth that whales – a few of which seem like sharks – are mammals confuses folks into pondering that sharks could also be mammals too.

Each sharks and mammals are vertebrates (i.e. they’ve backbones) and share a widespread ancestor that lived a whole lot of tens of millions of years in the past.

Each sharks and whales have clean, torpedo-shaped our bodies for travelling via the water with most effectivity. Each propel themselves with paddle-shaped limbs.

As well as, sharks and whales are additionally (typically) the identical colour!

Nevertheless, regardless of these similarities, sharks and cetaceans (aquatic mammals akin to whales, dolphins and porpoises) are solely very distantly associated.

The similarity in physique form (and different traits) in sharks and whales is a results of convergent evolution: the event of comparable traits in unrelated animals.

One other instance of convergent evolution are ichthyosaurs; these marine reptiles of the Mesozoic Period resemble the sharks and dolphins of right this moment.

Variations Between Sharks And Whales

  • Whereas a shark has fins, a whale’s forelimbs are often called “flippers” and its tail is named a “fluke“.
  • Fish propel themselves via the water with a side-to-side physique movement; a whale’s fluke strikes up and down.
  • Sharks have gills, which extract oxygen from the water; whales have to return as much as the floor to breathe air. (Whales breathe air by way of “blowholes” – openings on the highest of their heads which have developed from nostrils.)
  • A shark has a cartilage skeleton; A whale’s skeleton is product of bone.
  • Sharks are historic animals which have been swimming the world’s oceans for over 400 million years.
  • In comparison with sharks, cetaceans (the group of aquatic mammals that features whales, dolphins and porpoises) are comparatively “younger” animals, having solely appeared round 50 million years in the past.
  • None of a shark’s ancestors have ever left the ocean.
  • All residing mammals (even whales and dolphins) have developed from land animals.

Whereas sharks appeared lengthy earlier than the dinosaurs, the primary whales and dolphins solely appeared tens of millions of years after the dinosaur extinction on the finish of the Cretaceous Interval.

The ancestors of mammals (and all different land animals) developed from fish a whole lot of tens of millions of years in the past.

You may see an inventory of whale species on this web page: High Ten Greatest Whales, With Photos & Info

Whale Hair

Though whales look like hairless, they do have hair follicles (the organs from which hair grows), which are sometimes situated on the face, across the mouth. The younger of some whale species have hair earlier than being born.

Sharks don’t have hair. Their our bodies are lined with robust scales that allow them to swim quietly and effectively.

Is A Shark A Mammal? Dwell Younger

Tiger Shark
Tiger sharks give delivery to stay younger, however the best way wherein the younger develop differs from that seen in mammals.

As we’ve discovered, one attribute of mammals is giving delivery to stay younger (reasonably than laying eggs). Solely 5 mammal species reproduce by laying eggs.

The 5 mammals that lay eggs are the platypus, and the 4 species of echidna (spiny anteaters). These 5 species are often called monotremes.

Like mammals – and in contrast to many different fish – many sharks give delivery to stay younger. So on this respect sharks are much like mammals.

Nevertheless, there are variations in how the unborn sharks obtain nourishment whereas they’re rising contained in the mom (typically the younger sharks develop in eggs that hatch contained in the mom’s physique, a course of often called Ovoviviparity).

Round one quarter of shark species lay eggs. Shark eggs are protected by robust, leathery egg instances often called “mermaid’s purses“.

You could find out extra concerning the fascinating life cycle of a shark on these pages:


Mammals breathe utilizing lungs, whereas most fish (together with sharks) breathe with gills. Gills are organs that extract oxygen from water.

A shark can spend its entire life underwater; an aquatic mammal akin to a whale has to return as much as the floor to breathe at common intervals.

Are Sharks Mammals?

As we’ve discovered, though sharks are vertebrates, and most give delivery to stay younger – they lack many different mammalian traits.

Sharks don’t feed their younger with milk, neither have they got hair or lungs. As well as, the overwhelming majority of sharks are cold-blooded, whereas mammals are heat blooded.

Subsequently, sharks aren’t mammals.

Why Sharks Are Fish

Great Hammerhead Shark
Nice hammerhead shark

Fish are vertebrates (animals with a spine) which have gills (though some fish can breathe utilizing different strategies) and fins. These traits are present in all sharks.

What sort of fish is a shark?

Let’s have a look at the courses of residing fish to seek out out the place a shark belongs…

Jawless fish embrace hagfish and lampreys. They’re eel-like fish, with lengthy, skinny our bodies.

All sharks have jaws, subsequently sharks should not members of this group.

95% of fish species are bony fish. Bony fish have skeletons product of bone. Most bony fish have a swim bladder, which is a gas-filled organ that controls the fish’s buoyancy.

A shark doesn’t have a swim bladder, and has to swim to succeed in the required depth. Subsequently, sharks aren’t bony fish.

  • Chondrichthyes (Cartilaginous Fish)

Chondrichthyes are fish whose skeleton is product of cartilage, reasonably than bone. (Cartilage is like bone, however extra versatile.)

The skeletons of sharks are product of cartilage, subsequently sharks belong to the category Chondrichthyes, and are cartilaginous fish.

The scientist answerable for a lot of the best way we take into consideration animal classification is Swedish naturalist Carl Linnaeus (1707–1778). The Linnean Society is the world’s oldest organic society, and is called after him. (Web site)

Are Sharks Mammals or Fish? Conclusion

Are sharks mammals or fish? On this web page we’ve discovered that sharks should not mammals attributable to a lot of causes:

  • Sharks don’t produce milk to feed their younger.
  • Most sharks are cold-blooded (ectothermic) and can’t regulate their very own physique temperatures.
  • Sharks don’t have lungs, and breathe utilizing gills.
  • Sharks don’t have hair. Their our bodies are lined in laborious scales.

We’ve additionally discovered that sharks are fish.

As well as, as a result of sharks don’t have swim bladders and their skeletons are product of cartilage reasonably than bone, sharks are cartilaginous fish, of sophistication Chondrichthyes.

Different Shark Pages

Shark Info

Varieties Of Sharks

Do Sharks Lay Eggs?

Different Mammal Pages:

Mammals: An Introduction

What Is A Mammal?

Varieties Of Mammal

Mammal Evolution

Different Animal Questions

Is A Hen A Mammal?

Is A Dolphin A Mammal?

Are Birds Animals?

Is A Frog A Reptile?

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