Why is penguins not in the same group as fish?

Penguins are not in the same group as fish because they are fundamentally different types of animals. Here's why:

* Penguins are birds: They are warm-blooded vertebrates with feathers, wings, and lay eggs.

* Fish are aquatic vertebrates: They are cold-blooded and have gills for breathing underwater, fins for swimming, and scales.

While penguins have adapted to life in the water, they are still birds with the basic characteristics of birds. Fish, on the other hand, are a completely separate class of animals.