Starfish digest their food by putting their stomachs outside their bodies. This allows them to eat food beyond small crevices and even large pieces of food.

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.

They measure rectal temperature from the anus. We measure rectal temperature from the anus because the rectum is almost always in a closed state, is not easily affected by the outside world, and can maintain a constant body temperature.

When viewed from underwater, their white bellies allow them to blend in with the sunlight, making them harder to spot by other creatures.

The octopus has one brain in the center of its body and a small brain in each of its eight arms. By the way, there are three hearts.