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.

The dolphin has a smooth eggplant-like skin to reduce water resistance so that it can swim faster. Incidentally, dolphins renew their skin every two hours.

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.

They stay still in the cold deep sea to conserve energy as much as possible.

Because they mimic rocks and do not move much, moss grows on their bodies, so they molt regularly.