The term 'fish-eating mammal' refers to two animals: the otter and the SEAL. The otter is a semi-aquatic mammal that is found in many parts of the world, including North America, Europe, Asia, and Africa. It has a long, slim body and webbed feet, which help it to swim and catch fish. The SEAL is also a semi-aquatic mammal, but it is found mainly in the colder regions of the world, such as the Arctic and Antarctic. It has a thick layer of blubber and a streamlined body, which helps it to move quickly through the water and catch fish. Both the otter and the SEAL are important predators in their respective ecosystems, and they rely heavily on fish for their diet.