The
American lobster,
Homarus americanus, is a
species of
lobster found on the
Atlantic coast of
North America, chiefly from
Labrador to
New Jersey. It is also known as
true lobster,
northern lobster, or
Maine lobster. It can reach a body length of , and a
mass of over , making it not only the heaviest
crustacean in the world, but also the heaviest of all living
arthropod species. Its closest relative is the European lobster
Homarus gammarus, which can be distinguished by its coloration and the lack of spines on the underside of the
rostrum. American lobsters are usually bluish green to brown with red spines, but a number of color variations have been observed.