Question

Why the animals of colder regions and fishes in cold water have a thick layer of fat describe why?

Answer 1

the animals of colder regions and fishes in cold water have a thick layer of fat because due to the fat more heat is produced thus makes them warm.

Answer 2

We know that in colder regions like poles have so much cold that can even stop blood flow in veins.

So we can say that animals like fishes living in cold water have thick layer of fat because it don't allow the cold to touch the body which helps to avoid the uneven death.