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

Spotted garden eel (Heteroconger hassi) are waiting for food with their faces out of the sand. By keeping their bodies facing the direction of the current, they can catch food efficiently.

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 can be seen in the waters of Noboribetsu and Muroran during the warmer months of June through August.
They come to the waters of Hokkaido during the period when they are mating.

Hermit crabs that live on land have remnants from when they were in the water, and breathe through their gills and abdominal skin. They can only breathe in moist places.