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

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.

About 95-97% of their body is made up of water.

There are five species of wild seals that can be seen in Japan: bearded seal (Erignathus barbatus), ringed seal (Pusa hispida), spotted seal (Phoca largha), Harbor seal (Phoca vitulina), and ribbon seal (Histriophoca fasciata).
In Japan, these seals can basically only be seen in Hokkaido.

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.