Why is a baby shark called pup?

A baby shark is called a pup because it's a direct reference to the young of a mammal, like a dog.

While sharks are fish, the term "pup" is used for baby sharks because:

* Sharks give birth to live young: Unlike most fish, sharks do not lay eggs. They give birth to live young, just like mammals.

* Sharks are closely related to mammals: Sharks and mammals are both vertebrates and share a common ancestor.

* The word "pup" is used for young of many animals: The term "pup" is used for young of other animals, like seals and seals.

So, even though sharks are not mammals, the term "pup" is used to describe their young because of the way they reproduce and their evolutionary relationship to mammals.