American Lobster
Homarus americanus
Quick answer
The American lobster is a large marine crustacean with two powerful front claws, an armored shell, and ten legs. It lives on the cold, rocky seabeds of the northwest Atlantic and can grow heavier than 9 kg (20 lb). Lobsters molt their shells to grow throughout life and can live more than 50 years, making them among the longest-lived invertebrates.
American Lobster facts at a glance
| Scientific name | Homarus americanus |
|---|---|
| Diet | Omnivore (fish, mollusks, worms, algae) |
| Habitat | Cold rocky seabeds of the northwest Atlantic |
| Lifespan | Often 45–50+ years |
| Weight | 0.5–9 kg (1–20 lb) |
| Top speed | Up to 18 km/h (11 mph) in a tail-flip escape |
| Conservation status | Least Concern (IUCN) |
| Kingdom | Animalia |
|---|---|
| Phylum | Arthropoda |
| Class | Malacostraca |
| Order | Decapoda |
| Family | Nephropidae |
| Genus | Homarus |
Where it lives
Cold rocky seabeds of the northwest Atlantic, from Atlantic Canada to the northeastern United States.
Armor and claws
A lobster's body is protected by a hard external skeleton, or exoskeleton, and tipped with two unequal front claws. The larger, blunt crusher claw breaks open shells, while the smaller, sharper pincer claw grips and tears food. To escape danger, a lobster snaps its powerful tail to shoot backward through the water.
Molting and growth
Because its shell cannot stretch, a lobster must molt, shedding its entire exoskeleton to grow a larger one. Young lobsters molt often, while adults may molt only once a year or less. Just after molting the new shell is soft, leaving the lobster vulnerable until it hardens.
Diet and behavior
Lobsters are mostly nocturnal bottom feeders that eat fish, mollusks, worms, sea urchins, and algae, and will scavenge when needed. They shelter in rocky crevices by day and forage at night, using long antennae and sensitive leg hairs to find food in dark water. They can sense their surroundings well despite having a very simple nervous system.
Long life and fishing
American lobsters grow slowly and can live well over 50 years, continuing to grow throughout their lives. They support one of the most valuable fisheries in the North Atlantic, managed with rules on minimum and maximum sizes and protection of egg-bearing females. Healthy populations make them a Least Concern species overall.
Frequently asked questions about the American Lobster
How long do lobsters live?
American lobsters are long-lived and can survive more than 50 years in the wild. They keep growing throughout their lives by repeatedly molting their shells.
Why do lobsters turn red when cooked?
A live lobster's shell contains a red pigment bound to a protein, which masks the red color. Heat breaks that bond during cooking, releasing the red pigment and turning the shell bright red.
What do lobsters eat?
Lobsters are omnivores that eat fish, mollusks, worms, sea urchins, and algae. They are mostly nocturnal and will also scavenge dead animals on the seabed.
Why do lobsters have two different claws?
Lobsters have a large crusher claw for breaking open shells and a smaller, sharper pincer claw for gripping and tearing food. Which side becomes the crusher develops as the lobster grows.
How do lobsters grow if they have a hard shell?
Lobsters grow by molting, shedding their hard exoskeleton and forming a new, larger one. The fresh shell is soft at first and hardens over time, leaving the lobster vulnerable in between.
