Question

animals of colder regions and fishes of cold water have thicker layer of subcutaneous fats. why?

Answer 1

it's naturally occurs on them to survive in that region

Answer 2

animals of colder regions and fishes of cold water have thicker layer of subcutaneous fats because fats helps to keep body warm protects animals from extreme winters . it acts as an insulator in colder regions for animals . Animals in colder regions have thick layers of fat, because fat acts as an insulator and doesn't let their body heat escape, which helps them survive in such extreme temperatures.
hope this answer is useful to u if helps plz mark it as brain list