The harbor seal (Phoca vitulina) is the most widely occurring phocid seal in the world. In the United States, it is found on both the east and west coasts.  Their size varies fairly widely across their distribution with the smallest animals weighing around 80-90kg (N. Gulf of Alaska) and the largest animals weighing up to about 170kg (Aleutian Islands). Coloration patterns can also vary between individuals within a population such that they can appear light with dark spots or dark with lighter spots, though often times it is difficult to tell the difference within a population. There is also sexual dimorphism present in this species with males being generally larger than females. You can further explore the normal anatomy of the harbor seal below. Note that many images in the normal anatomy section also feature the Northern Elephant Seal, another phocid species.