Are fish mammals? || Are whales mammals or fish?|| Updated 2021

Are fish mammals?

Most of us think that either fishes are mammals or are they different creatures. No fishes are not mammals, however there are some particular individuals in the fish family that come under the marine mammal category. It includes whales, dolphins etc.

Fishes are neither mammals and they also do not come under the division of amphibians. Taxonomically, fish come under the extinct term called “pisces” or “ichthyes”.

Fish is an aquatic creature bearing a body and skull made up of hard cartilage. They have gills instead of lungs and they do not have limbs, but they have digits all over their bodies.

They are related to a group called “Tunicates”. Tunicates are also  marine creatures but are invertebrates. So fish together with Tunicates form another group known as “olfactory”.

Fishes are the most abundant creatures of the wild. As our Earth is covered with 70% water you can expect their abundance. Most of the marine animals and fishes are cold blooded, the scientific term for the cold blooded organisms is “ectothermic”.

Fish are present everywhere, either in the ocean, rivers, and you can even find them in the deepest parts of the ocean where it is very difficult for any life to survive.

Are whales mammals or fish?

There are certain marine creatures that come under the category of mammals and we do not know about it. They are whales, dolphins, and porpoises. There are almost  75 species of dolphins present in the world. These creatures are miraculous marine mammals that can spend their entire life in the water.

Similar to the other mammals, whales are also warm blooded, they are not cold-blooded like other fishes. Unlike fishes who have gills for breathing, whales and dolphins on the other hand have a pair of lungs like mammals through which they perform respiration.

However both whales and dolphins have to come up to the ocean’s surface so that they can fill their lungs with air again. They have to perform this activity frequently.

Both whales and dolphins have “blowholes” on their heads and they use them to come up to the surface. With this hole these marine mammals are able to catch a breath.

Another very important feature that makes whales and dolphins mammals is their mode of reproduction. Unlike fish, whales and dolphins do not lay eggs in the water. Instead they perform live birth just like the males. Not only this their young ones nurture their milk and are also dependent on their parents.

Another very important essential is that whales also have a little amount of hair on their blow head. Fish on the other hand only have scales. So whales are mammals and they are not fish.

Are fish mammals

Are fish mammals or reptiles?

No fish are not mammals nor are they reptiles . Only whales, and dolphins come under the category of mammals. The classification of fish is a little bit tricky. Fish belongs to three classes of vertebrates, it includes:

  • Chondrichthyes ( fishes made up of cartilage)
  • Osteichthyes ( Fishes having bony framework)
  • Agnatha ( Jawless fishes)

However all of the above former classes are subdivisions of the mammals and the birds etc. So it is very hard to explain right now under which category do fish fall in.

So, fish are the members of the chordate which is a phylum, but they are not related to tetrapod’s that includes reptiles and some amphibians.  So there are plenty of fishes present on the earth which are not reptiles or mammals. So we cannot particularly categorize fish in either of these categories.

Why are sharks fish not mammals?

There is a certain criteria to be a mammal and sharks do not fit in that certain criteria. They do not exhibit any behavior or anatomical similarity which makes them related to mammals.

Sharks are cold blooded while mammals are warm-blooded. On the other hand, the framework of the shark is made up of cartilage while a mammal’s body is made up of bones.

Like fish, sharks also reproduce opting the method of egg laying On the other hand, mammals perform live birth to reproduce their next generations.

Also, sharks also have fins and gills for respiration while mammals use lungs for the very similar cause. Sharks are thereby a  species of fish that are cold-blooded and are predatory fishes. They feed on the smaller fishes for their survival.

Are dolphins fish mammals or amphibians?

Dolphins live under the water but they are mammals. This statement will be confusing to many. But there are certain specifications which prove this statement that dolphins are mammals

  • Dolphins are warm-blooded like mammals. On the other hand, fishes and amphibians are cold-blooded.
  • Fishes have gills and fins through which they perform gaseous exchange and respire. But, dolphins have a pair of lungs which is a trait similar to mammals.
  • Also, dolphins give live birth to their young ones. On the other hand, fishes opt for the egg laying method.
  • Dolphins cannot be amphibians as well because they have much larger and complex brains unlike amphibians.
  • Dolphins also feed their young ones in milk and they also nurture them until they can take care of themselves.
  • Dolphins also bear some hair on the hole through which they blow the hair out. While fishes only have scales on their body and they do not have hair.

Sharks are fish not mammals

Sharks are not mammals and they cannot be mammals. You have to fulfil some special characteristics to be a mammal and sharks obviously don’t have any of them.

Sharks are a special species of fish. Their framework is very sturdy and is made up of cartilage. The most important thing that differentiate sharks from mammals is that they do not have hair. They also give eggs to reproduce while mammals give birth to their young ones, which means the offspring of mammals are completely developed when they are born.

Another factor that inhibits sharks from being mammals is that they have a swim bladder which keeps them afloat in the water. On the other hand mammals do not exhibit any such anatomical similarity.

Similarly, mammals have a pair of lungs through which they excrete carbon dioxide and inhale oxygen while sharks like fish have fins and gills through which they perform gaseous exchange.

Sharks do not nurture their young one like mammals. Once they lay eggs shark babies then are on their own. While the young ones of the mammals are dependent on their parents for a certain period of time until they can take care of themselves.

Sharks do not produce milk which means they do not have the mammary glands while mammals feed their children through milk. So that proves that sharks are not related to mammals.

Are seals mammals or fish?

Seals are marine mammals which means they are mammals thriving beneath the water under the sea or ocean. As you know seals are not always in the water which explains that seas or sea lions are partially aquatic. It means that they are not dependent on water for their survival like fish.

They belong to a group called “Pinipod ”, members in this group have fin-like feet, which is their only resemblance with a fish. According to the statistics mentioned by the Seals World, there are a total of 18 different species of seals present in the world. Like all other mammals, male seals are heavier and bulkier while females are lighter and smaller in size.

True seals live in cold habitats. Yep! You guessed it right we are talking about those seals that you see on the Discovery channel covered in snow. Some true seals often find cavities and make space in the snow to form an igloo shaped living area. That igloo is obviously not perfect but it provides them warmth and protection.

Are fish mammals

Are there more species of mammals and fish?

Tell me it is very difficult to tell how many animal species are present on the earth. Because there are so many kinds of animals about which we do not know yet. There is so much to explore about life and animals on the Earth.

Right now there are almost ten thousand animal species which science discovers each day. If you want an exact number of total animals in the world, then right now they range from 20 million to 50 million and scientists, biologists are on the hunt to discover more and more animals each day.

Total number of species by classification:


Are manatees mammals or fish?

Manatees belong to the family Trichechidae, and their genus is Trichechus. These are huge aquatic marine mammals. Manatees are most known as “Sea cows”. They are herbivores just like the cows present on the land.

Manatees are large and huge mammals, their head is similar to the shape of an egg. They bear flippers like fish and they also have a tail which is flat like a spatula. As you know they are known as sea cows, so there is something about them which justifies their name.

They are called sea cows, because they are huge, slumber, and have a relatively very slow gait and nature. There are very few chances for them to be eaten but they still can be eaten by bigger fishes because they are too slow. However, whatever their name is they are most related to the elephants.

Are puffer fish mammals?

Puffer fishes are very odd looking and usually look like an inflated balloon. However, to answer your query puffer fishes are not mammals. Like all other fishes they bear vertebrae.

Puffer fish is puffy because it consumes a huge amount of water through its stretchy mouth. You may not know but puffer fishes are dangerous and are very poisonous. They are on second number after the poison dart frog in reference to their toxicity.

Are all fish mammals?

No! Not all fish are mammals. Fish have their separate classification and they exhibit characteristics that are unique to its own species. Fishes have swim bladders for buoyancy, they also have fins and gills for respiration. Fishes lay eggs for reproduction. All of these features clash with the features of the mammals and inhibit the fish to be mammals.

Mammals are warm blooded while fish are cold blooded. Only whales, dolphins and a few other aquatic creatures are termed as marine mammals. Despite them a plenty of marine organisms are not mammals

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