No fish is accessible. As bitter winter creeps in creatures like polar bear, certain species of squirrels, rabbits, etc. seek resting places where they roll up like a ball and go into hibernation, that is motionless sleep for 4 or 5 months. Their respiration and heartbeat become far too shallow and slow to notice. This greatly lowers the energy demand. The minimal energy consumed is derived from the reserve of their body fat.
Hibernation lasts till the return of spring, when they wake back in a bony-skinny shape.
Yogis demonstrate weeks of death like feat, barely breathing, with absolutely no intake of food or water. Spiritual masters are known to have been in trance for months in a frozen state with absolutely no movements or food. We readily accept the phenomena of hibernation, yogi state and spiritual trance. Prolonging Lifespan Scientific research is afoot to induce hibernation in human beings. If it succeeds there will be a big breakthrough in space exploration.