Why are whales classified as mammals but not fish?

-Whales are warm-blooded animals, whereas fishes belong to cold-blooded animals. -Whales breathe air through a pair of lungs, while fishes respire through its gills. -Whales possess mammary glands, but such mammary glands are not found in fishes.Dec 9, 2020

Why are sharks not mammals?

Despite names like ‘whale sharkwhale sharkIt is the sole member of the genus Rhincodon and the only extant member of the family Rhincodontidae, which belongs to the subclass Elasmobranchii in the class Chondrichthyes.https://en.wikipedia.org › wiki › Whale_sharkWhale shark – Wikipedia’, all sharks are fish and differ in many ways from mammals. For example, mammals breathe air through lungs, feed their young with milk and are warm-blooded. Sharks pass water over gills to breathe, don’t have mammary glands and (with the exception of mackerel sharks) are cold-blooded.

Why are sharks not mammals but dolphins are?

Dolphins, and other mammals, are warm blooded, give birth to live young, nurse their young, are born with hair, and breathe air. Sharks, like other fish, have gills to remove oxygen from the environment, are cold blooded, and have scales.Aug 5, 2019

How do biologists know that whales are mammals and not fish?

Why are whales classified as mammals and not fish? Whales are mammals because they are warm blooded, give birth to live young, and are genetically very similar to land animals such as us, (when compared to fish). They are land mammals that have evolved back into ocean going creatures.Nov 1, 2015

Why is a whale a mammal and a shark is not?

Despite names like ‘whale sharkwhale sharkIt is the sole member of the genus Rhincodon and the only extant member of the family Rhincodontidae, which belongs to the subclass Elasmobranchii in the class Chondrichthyes.https://en.wikipedia.org › wiki › Whale_sharkWhale shark – Wikipedia’, all sharks are fish and differ in many ways from mammals. For example, mammals breathe air through lungs, feed their young with milk and are warm-blooded. Sharks pass water over gills to breathe, don’t have mammary glands and (with the exception of mackerel sharks) are cold-blooded.