Homarus americanus

American lobster Temporal range: Pleistocene–Recent PreЄ Є O S D C P T J K Pg N ↓
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Crustacea
Class:	Malacostraca
Order:	Decapoda
Family:	Nephropidae
Genus:	Homarus
Species:	H. americanus
Binomial name
Homarus americanus H. Milne-Edwards, 1837
Natural range of H. americanus (blue)
Synonyms
Astacus marinus Say, 1817 (non Fabricius, 1775) Astacus americanus Stebbing, 1893 Homarus mainensis Berrill, 1956

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 Atlantic lobster, Canadian lobster, true lobster, northern lobster, Canadian Reds, or Maine lobster. It can reach a body length of 64 cm (25 in), and a mass of over 20 kilograms (44 lb), 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 several color variations have been observed.

Homarus americanus is distributed along the Atlantic coast of North America, from Labrador in the north to Cape Hatteras, North Carolina in the south. South of New Jersey, the species is uncommon, and landings in Delaware, Maryland, Virginia and North Carolina usually make up less than 0.1% of all landings. A fossil claw assigned to Homarus americanus was found at Nantucket, dating from the . In 2013, an American lobster was caught at the Farallon Islands off the coast of California.