The desert fennec is a small fox that lives in the sahara desert. it has long limbs and long ears. compared to the desert fennec, you might expect the arctic fox to have

Compared to the desert fennec, you might expect the arctic fox to have shorter ears.
Given that the desert fennec fox lives in the desert, where it is quite dry and hot, and the arctic fox lives in a place where it is extremely cold, by analogy, if the first fox has long ears, the second one will have shorter ears. Because the locations they live in are quite different, their ears are going to be each other's opposites.