Question

Why animals and fishes of colder region have thicker layer of sub cutaneous fat?

Answer 1

I think the question is wrong.How can they survive in cold region by thick layer of fat?I think they have fat layer.

Answer 2

basically adipose tissue(fat tissue ) protects us from the coldness around us.

whereas in polar regions there is extreme cold present in the environment so to bare that chillness they should have more fat in the sense thick layer of adipose tissue in order to protect themselves from their external environment.