Its closest relative is the European Lobster (Homarus gammarus), which is similar in size and shape but darker blue in color and found in the eastern Atlantic.
8 to 24 in (20 to 60 cm)
Length
1 to 9 lbs (0.5 to 4 kg)
Weight
About
The American Lobster (Homarus americanus) is the largest species of lobster in the world and belongs to the family Nephropidae. Native to the cold waters of the northwestern Atlantic Ocean, it ranges from Labrador in Canada down to North Carolina in the United States, though it is most abundant in the Gulf of Maine. This crustacean is not only an ecological keystone but also one of the most economically valuable seafood species.
American Lobsters are characterized by their robust bodies, hard exoskeletons, and two large, unequal claws. The larger “crusher claw” is adapted for breaking shells, while the smaller “cutter claw” is designed for slicing. Their coloration is typically a mottled greenish-brown, providing camouflage on the seafloor, though rare genetic variations can produce blue, yellow, calico, or even albino individuals. Adults can reach lengths of over 24 inches (61 cm) and weigh more than 40 pounds (18 kg), with the largest recorded lobster exceeding 44 pounds.
They inhabit rocky and sandy bottoms at depths ranging from the shoreline to 1,600 feet (500 meters), though most are found in shallower, cooler waters. Primarily nocturnal, lobsters emerge from burrows and crevices at night to forage. Their diet consists of fish, mollusks, crustaceans, and plant matter, making them opportunistic omnivores.
Reproduction occurs in summer when females molt and mate with males, after which they carry fertilized eggs under their tails for up to a year. Juveniles are highly vulnerable, spending time in the planktonic stage before settling to the seafloor. Adult lobsters can live for decades, with some estimated to surpass 50 years in age.
Conservation efforts and strict fishery management have kept American Lobster populations relatively stable, though warming oceans and shifting ecosystems pose future challenges. Their impressive size, distinctive claws, and cultural importance make them an iconic species of North America’s Atlantic coast.
Threatened:
Extinct
Critically Endangered
Endangered
Vulnerable
Near Threatened
Least Concern
Physical Characteristics
The American Lobster (Homarus americanus) is the largest crustacean in the Atlantic Ocean, distinguished by its massive claws and armored body.
Coloration:
Typically dark bluish-green to greenish-brown, which helps with camouflage on rocky seafloors. Rare color morphs occur, including blue, yellow, calico, and even albino (white) individuals.
Head and Eyes:
They have stalked compound eyes that detect movement and light. Long, sensitive antennae extend forward, used for touch and detecting chemical signals in the water.
Body:
The body is segmented and covered in a hard exoskeleton (carapace) that provides protection. Lobsters periodically molt this shell to grow.
Claws (Chelipeds):
They possess two large, unequal claws:
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Crusher claw: Thick and heavy, used to break shells.
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Pincer claw: Narrower and sharper, used for cutting and tearing prey.
Legs:
In addition to the claws, they have four pairs of walking legs and several smaller appendages under the body for swimming, grooming, and carrying eggs.
Tail (Abdomen):
The muscular tail ends in a fan-shaped structure called the uropod, used for rapid backward swimming (tail-flipping escape response).
Size:
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Length: Adults average 8 to 24 in (20 to 60 cm).
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Weight: Most weigh 1 to 9 lbs (0.5 to 4 kg), though record individuals can exceed 40 lbs (18 kg).
Sexual Dimorphism:
Males tend to have larger claws relative to body size, while females have broader tails to carry eggs.
The American Lobster’s powerful claws, armored shell, and ability to reach record sizes make it one of the most iconic marine invertebrates of the North Atlantic.
Reproduction
The American Lobster has a complex reproductive cycle tied to molting and seasonal behaviors.
Mating and Courtship:
Mating occurs after the female molts, when her shell is soft. Males court females by approaching with displays of their claws, followed by gentle contact.
Breeding Season:
Breeding typically takes place in summer and early autumn, though timing varies by region and water temperature.
Fertilization:
During mating, the male deposits a sperm packet inside the female, which she stores for months until she is ready to release eggs.
Egg Development:
Females carry fertilized eggs externally on the underside of their tails, attached to swimmerets. A single female may carry 5,000 to 100,000 eggs depending on her size.
Incubation:
Eggs are carried for 9 to 12 months, turning from bright orange to dark brown as they develop.
Hatching of Larvae:
Larvae hatch in late spring or summer, floating to the surface as plankton. They pass through three planktonic stagesbefore settling to the seafloor as juveniles.
Nurturing and Care:
Unlike mammals, lobsters do not provide direct care beyond carrying eggs. Survival rates are very low—fewer than 1 in 1,000 larvae reach adulthood.
Maturity:
Lobsters reach sexual maturity at about 5 to 8 years, when they are around 1 lb (0.45 kg) in weight.
The American Lobster’s high egg production but low larval survival reflects its strategy of quantity over care, ensuring that some offspring survive in a competitive marine environment.
Lifespan
The American Lobster is one of the longest-living marine invertebrates, with survival shaped by molting cycles, predation, and fishing pressure.
Lifespan in the Wild:
They can live 40 to 60 years or more, with some individuals believed to exceed 100 years. Their continuous molting and ability to keep growing throughout life contribute to their longevity.
Lifespan in Captivity:
Lobsters kept in aquariums or tanks can survive for many years if conditions replicate their natural habitat, though stress and disease may shorten lifespan compared to the wild.
Threats to Longevity:
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Fishing Pressure: Trapping is the primary threat, as lobsters are heavily harvested for food.
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Predation: Young lobsters face high predation from fish, crabs, and other marine species.
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Molting Stress: Molting requires energy and leaves lobsters vulnerable until their shell hardens.
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Disease: Shell disease and parasites can reduce survival.
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Climate Change: Rising ocean temperatures and acidification threaten lobster habitats and reproduction.
Conservation measures, including regulated fisheries, size limits, and protected areas, are key to ensuring the American Lobster’s long natural lifespan in the Atlantic Ocean.
Eating Habits
The American Lobster is an opportunistic omnivore with feeding habits adapted to the rocky seafloor.
Diet:
They consume a wide range of prey, including fish, crabs, clams, mussels, sea urchins, worms, and small shellfish. They also feed on decaying matter, acting as natural scavengers.
Hunting Strategy:
Lobsters are primarily nocturnal hunters, emerging from their burrows at night to forage. They rely on strong claws and keen chemosensory antennae to detect and capture prey.
Foraging Behavior:
They prefer rocky, complex habitats that provide both prey and shelter. While juveniles rely on small invertebrates, adults can crack hard shells with their crusher claw.
Feeding Technique:
The crusher claw breaks open shells, while the pincer claw tears and slices soft tissue. Food is brought to the mouthparts, where it is shredded before ingestion.
Feeding Frequency:
They do not need to eat daily but consume large meals when prey is abundant. Their slow metabolism allows them to survive extended periods without food.
Adaptations:
Powerful claws, sensitive antennae, and flexible diets enable lobsters to thrive in diverse environments from shallow coastal waters to depths over 1,500 ft (457 m).
The American Lobster’s dual role as both predator and scavenger makes it a key species in maintaining balance on the North Atlantic seafloor.
Uniqueness
The American Lobster (Homarus americanus) is one of the most iconic marine invertebrates, notable for its size, resilience, and cultural importance.
Largest Lobster Species:
It is the largest crustacean in the world, with record individuals weighing over 40 lbs (18 kg) and exceeding 3.5 ft (1.1 m) in length.
Dual Claws:
Their two specialized claws—a crushing claw and a cutting claw—set them apart from many other crustaceans, allowing them to tackle a wide variety of prey.
Long Lifespan and Growth:
Lobsters molt throughout their lives, continuing to grow for decades. This allows some individuals to reach exceptional sizes and ages, potentially over 100 years.
Color Variations:
While most are dark greenish-brown, rare genetic variations produce blue, orange, calico, and even albino lobsters, making them prized finds.
Regeneration:
They can regenerate lost claws, legs, and antennae, an adaptation that enhances survival in predator-rich environments.
Cultural and Economic Importance:
The lobster fishery is one of the most valuable in North America, with the species deeply tied to the culture and cuisine of New England and Atlantic Canada.
The American Lobster’s immense size, long life, rare color morphs, and dual-claw adaptations make it one of the most unique and fascinating invertebrates of the ocean.
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FAQ’s
1. What species is closest to the American Lobster?
2. How does the American Lobster compare to other lobsters?
It is the largest lobster species in the world, heavier than spiny lobsters and slipper lobsters, and is distinguished by its two oversized claws used for crushing and cutting.
3. What national parks provide the best opportunities to see an American Lobster?
They are commonly found in marine parks such as Acadia National Park (USA), Fundy National Park (Canada), and Kouchibouguac National Park (Canada) along the North Atlantic coast.