here are 18 seal species still inhabiting the seas today, but not long ago there were 19 species. The Caribbean monk seal was last sighted in 1952 and is now listed as extinct. One of the seal species on the endangered species list is the Hawaiian monk seal (Monachus schauinslandi).
Seals can be found in all the oceans and a few freshwater lakes, one of which is Lake Baikal in Russia which is the only place in the world where you can find it. There can be big differences between different species. The largest seal, the elephant seal, can weigh many times more than smallest seal. The elephant seal can weigh more than 5,000 pounds! Adult ringed seals, the smallest of all pinnipeds, can weigh as little as 110 pounds. Another difference is the coloration of the different seal species. The ribbon seal has white markings, like a ribbon, that encircle parts of their bodies. Some other seals are nearly uniform in color.
What are the characteristics of all seals? Well, seals do not have an ear that extends from the skull, but they can still hear well. Also, seals propel themselves through the water with their rear flippers while their front flippers are used for steering. The front flippers of seals are short with sharp claws. Seals cannot use their rear flippers to walk on land or ice and most appear awkward when moving on these surfaces. Seals have a torpedo like shape in the water and use their rear flippers to move rapidly to catch prey and escape predators.