Members of the toothed " Toothed whale" family, such as the Common bottlenose dolphin and Pacific white-sided dolphin, have almost completely lost their olfactory structures, such as the nerves that sense smell.
This is because dolphins live in water and do not need it during the evolutionary process.

Because they have a lot of fat, they are able to maintain their body temperature.

Penguins are flightless birds, or avifauna. They used to fly in the past, but it is thought that they evolved and stopped flying. Instead, they became good at swimming & diving.

They can stay underwater for 7 to 8 minutes.

It is called “gaya” because it can be caught in large numbers.
*Hurly-burly is expressed as wai-wai-gaya-gaya in Japanese.