The fish moves up the river to spawn, a walrus stays warm in the cold ocean are the results of an organism having lipid in its body.
Explanation:
The fish have energy deposited in the form of fat or lipids, they do not feed during spawning and gets energy from the fats.
A walrus has good insulation of fat layer over their bodies as they live in the arctic region. The thick layer of lipid/ fat helps it to survive in freezing temperatures.
