American Lobster – Profile | Traits | Habitat | Biology | Breeding

American lobster

The American lobster, scientific name Homarus americanus, is discovered alongside the Atlantic coast of North America in the area from Labrador, Canada to North Carolina, United States. They are most prevalent alongside the New England coast. The American lobster is present in shallow waters however is more plentiful in deeper waters and may live as far deep as 365 m.

American lobster profile

The American lobster (Homarus americanus) is a species of lobster discovered on the Atlantic coast of North America, mainly from Labrador to New Jersey.

American lobster is also referred to as Atlantic lobster, Canadian lobster, true lobster, northern lobster, Canadian Reds, or Maine lobster.

The American lobster can attain a body size of 64 cm (25 in), and a mass of over 20 kilograms (44 lb), making it not solely the heaviest crustacean on the earth, but additionally the heaviest of all dwelling arthropod species.

Its closest relative is the European lobster Homarus gammarus, which may be distinguished by its coloration and the dearth of spines on the underside of the podium.

American lobsters are normally bluish-green to brown with red spines, however, several coloration variations have been noticed.

The American lobster reaches weights of at the very least 45 pounds (20 kg) and is the biggest crustacean on the earth by weight.

Along with true crabs, prawns, and different lobsters, the American lobster is a decapod; it has ten legs, and it’s lined with a spiny exoskeleton that gives it some safety from potential predators.

Most American Lobsters are rusty brown in coloration, however, all kinds of unusual colors/patterns have been not often noticed by fishers and scientists.

These embody people which might be brilliant blue, green, mottled, and even some which might be completely divided down the center with completely different colors on either side (e.g., half blue, half black; half black, half red; and so forth.).

The American lobster’s front legs are modified into very giant claws. The two claws are barely completely different from one another, with one being stronger and used for crushing whereas the opposite is sharper and used for slicing. Like in all decapods, the American lobster’s shell actually is a skeleton on the surface of its body.

The exoskeleton doesn’t develop, and due to this fact, the lobster should molt it often so as to develop larger. Before molting, a person begins building a brand new, bigger skeleton inside the prevailing one.

As it will get too huge to be contained, it splits open the outer shell, and the brand new exoskeleton hardens. During this process, the brand new exoskeleton may be mushy for a number of hours, and the lobster is very susceptible to predation.

During the day, American lobsters stay in hiding locations alongside their rocky reef habitats. During the twilight hours and at night, people are a lot more lively and forage alongside the reef for a wide range of prey, together with many varieties of invertebrates, decaying natural matter, and a few algae.

American lobster, Homarus americanus

These lobsters will eat most issues that they discover. Large fishes and octopuses are recognized to eat adult American lobsters, and a bigger number of fishes eat the juveniles.

Unlike many aquatic species, American lobsters reproduce by way of inside fertilization. After a male passes his sperm to a feminine, she shops the fertilized eggs on the ventral aspect of her body till they hatch.

American lobsters help an enormous fishery within the northwestern Atlantic Ocean, where a number of profitable management rules have been utilized to make sure that the fishery will proceed to be viable in the long run.

These embody size limits, gear limits, and different management methods. Currently, populations appear to be stable, and scientists don’t imagine that this species is in any danger of going extinct.

However, it is a very important procedure to watch populations so as to be sure that the fishery stays viable and the species stays healthy.


Homarus americanus, American lobster is distributed alongside the Atlantic coast of North America, from Labrador within the north to Cape Hatteras, North Carolina within the south.

South of New Jersey, the species is unusual, and landings in Delaware, Maryland, Virginia and North Carolina normally make up lower than 0.1% of all landings.

A fossil claw assigned to Homarus americanus was discovered at Nantucket, courting from the Pleistocene. In 2013, an American lobster was caught on the Farallon Islands off the coast of California. It has been launched in Norway and doubtlessly Iceland.

American lobster Description

Homarus americanus, American lobster generally reaches 8–24 inches (200–610 mm) long and weighs 1–9 pounds (0.45–4.08 kg) in weight, however, has been recognized to weigh as a lot as 44 lb (20 kg), making this the heaviest crustacean on the earth.

Together with Sagmariasus verreauxi, American lobster is also the longest decapod crustacean on the earth; an average adult is about 9 in (230 mm) long and weighs 1.5 to 2 lb (680 to 910 g).

The longest American lobsters have a body (excluding claws) 64 cm (25 in) long. According to Guinness World Records, the heaviest crustacean ever recorded was an American lobster caught off Nova Scotia, Canada, weighing 44.4 lb (20.1 kg).

Homarus americanus, American lobster is the biggest species of lobster and may attain a size of as much as 1.1 m and a weight of 20 kg. However, the size of a lobster that is often caught is roughly 25 cm in size and weighs about 0.5 kg.

A lobster’s body is split into twenty-one segments: six segments from the pinnacle area, eight segments compose the thorax (mid-section), and 7 segments make up the stomach (usually referred to as the tail).

American lobster, Homarus americanus

Commonly considered to be red, the body is absolutely blackish-green or brownish-green. The red coloration outcomes when a lobster is boiled and is a results of pigments within the shell breaking down.

The eyes are on the first section of the pinnacle and are stalked. They can solely detect movement in dim light. The second section of the pinnacle has anntenules with delicate hairs which have more than 400 varieties of chemoreceptors. The lobsters can detect different species, potential mates, prey, and predators with the receptors.

Being within the Order Decapoda (which means “ten feet”), the lobster has ten legs. Five pairs of jointed legs lengthen from the thorax area. The first pair of those legs extend in the direction of the pinnacle and have claws (chela) on the end.

One claw is normally bigger than the opposite and has thick teeth that are used to crush objects. The different claw normally is smaller and has sharp teeth used for slicing.

Lobsters undergo distinctive growth throughout their lifetime. When they first hatch, a lobster weighs lower than one-tenth of a gram. By the time they’re full adults, they will attain a weight of as much as 10 kilograms.

This growth is a rise of 100,000 instances. Lobsters obtain this growth by going by way of intervals referred to as molts. When a lobster is able to molt, its body absorbs the mineral salts that had hardened its shell, drawing the salts additional into its skin.

When the shell softens, the lobster is ready to break it and slide out. The lobster takes in more water and thus swells in size. The new shell is already masking its body however takes a couple of days to harden.

During this period the lobster stays in seclusion to keep away from predators. Each time a lobster molts its body can develop 10-15% in size. Newly hatched lobsters molt for the first time throughout the first week and three more instances throughout the first month.

American lobster, Homarus americanus

American lobster Head

The antennae measure about 2 in (51 mm) long and cut up into Y-shaped constructions with pointed suggestions. Each tip reveals a dense zone of hair tufts staggered in a zigzag association.

These hairs are lined with a number of nerve cells that may detect odors. Larger, thicker hairs discovered alongside the sides control the stream of water, containing odor molecules, to the interior sensory hairs.

The shorter antennules present an additional sense of odor. By having a pair of olfactory organs, a lobster can find the path a smell comes from, a lot the same method people can hear the path a sound comes from. In addition to sensing smells, the antennules can decide water pace to enhance direction-finding.

Lobsters have two urinary bladders, situated on both aspects of the pinnacle. Lobsters use scents to speak what and the place they’re, and those scents are within the urine.

They mission long plumes of urine 1–2 meters (3 ft 3 in–6 ft 7 in) in front of them, and accomplish that after they detect a rival or a possible mate within the space.


The first pair of pereiopods (legs) is armed with a big, uneven pair of claws. The bigger one is the “crusher”, and has rounded nodules used for crushing prey; the opposite is the “cutter”, which has sharp interior edges and is used for holding or tearing the prey.

Whether the crusher claw is on the left aspect or right aspect of its body determines whether or not a lobster is left or right-handed.

American lobster, Homarus americanus


The regular coloration of Homarus americanus is bluish-green to brown with red spines attributable to a combination of yellow, blue, and red pigments that happen naturally within the shell.

On uncommon occasions, these colors are distorted attributable to genetic mutations or situations making a spectacle for many who catch them.

In 2012 it was reported that there was a rise in these “rare” catches attributable to unclear causes. Social media affect making reporting and sharing more accessible to a drop in predator populations have been instructed as possible causes. The lobsters talked about below thus normally obtain media protection attributable to their rarity and eye enchantment.

American lobster Biology

American lobsters have a long life span. It’s troublesome to find out their precise age as a result of they shed their onerous shell after they molt, leaving no proof of age. But scientists imagine some American lobsters could live to be 100 years old.

They can weigh as much as 44 pounds.

Lobsters should periodically molt so as to develop, shedding their onerous, exterior skeleton (shell) after they develop too giant for it and forming a brand new one.

They eat voraciously after they molt, usually devouring their very own just lately vacated shells. Eating their shell replenishes lost calcium and helps harden their new shell.

Lobsters molt about 20 to 25 instances over a period of 5 to eight years between the time they hatch and when they’re able to reproduce and attain the minimal authorized size to be harvested.

Usually, lobsters mate after the female’s molt. Males deposit sperm within the soft-shelled females. The feminine shops the sperm internally for as much as a year.

Females can have 5,000 to more than 100,000 eggs, relying on their size. The eggs are fertilized as females launch them on the underside of their tails, the place they carry the eggs for 9 to 11 months.

American lobster, Homarus americanus

Egg-bearing females transfer inshore to hatch their eggs throughout the late spring or early summer season.

The pelagic (free-swimming) larvae molt 4 instances before they resemble adults and settle to the underside.

Lobsters are opportunistic feeders, feeding on no matter prey is most accessible, so their diet varies regionally.

Larvae and postlarvae are carnivorous and eat zooplankton (tiny floating animals) throughout their first year.

Adults are omnivorous, feeding on crabs, mollusks, worms, sea urchins, sea stars, fish, and macroalgae.

In common, a wide range of bottom-dwelling species feeds on lobster, together with fish, sharks, rays, skates, octopuses, and crabs. Young lobsters are particularly susceptible to predators. Large, hard-shelled lobsters could also be proof against predators (besides people).

American lobster Habitat

The American Lobster lives on the underside of the ocean. They may be present in sandy and muddy areas, however want rocky bottoms with more locations to cover.

Young lobsters appear to want to settle in areas with cobble. The lobster spends many of the days inside its burrow and can solely go away if meals are close by.

At night it wanders the ocean floor and will enterprise into the intertidal zone when tides are high. If a predator approaches, it shortly retreats back into the protected cover of its burrow.

American lobsters are discovered within the northwest Atlantic Ocean from Labrador to Cape Hatteras. They’re most plentiful in coastal waters from Maine by way of New Jersey and are additionally widespread offshore to depths of two,300 feet from Maine by way of North Carolina.

American lobster, Homarus americanus

American lobster Food Habits

Three stomachs make up the digestive system, which is throughout the cephalothorax (the pinnacle and thorax). The first abdomen (forgut) grinds meals into small particles with grinding teeth.

The second abdomen (midgut) has glands to digest particles. The glands are the green portion of the lobster eaten by some people (referred to as the “tomalley”). The third abdomen (hindgut) receives non-absorbed particles that are handed to the rectum and anus.

Homarus americanus does nearly all of its consumption at night. It is normally a scavenger, feeding on useless animals, however can be able to capture its personal prey.

The lobster’s diet consists principally of clams, crabs, snails, small fish, algae, and different vegetation referred to as eelgrass.

Since lobsters typically eat their very own molted shell they had been regarded as cannibalistic, however, this has by no means been recorded within the wild. However, they’ll eat different lobsters when in captive

American lobster Diet

The natural diet of H. americanus is comparatively constant throughout completely different habitats. It is dominated by mollusks (particularly mussels), echinoderms, and polychaetes, though a large range of different prey gadgets could also be eaten, together with different crustaceans, brittle stars, and cnidarians.

Lobsters in Maine have been proven to realize 35–55% of their energy from herring, which is used as bait for lobster traps. Only 6% of lobsters coming into lobster traps to feed are caught.

American lobster, Homarus americanus

American lobster Life cycle and reproduction

A feminine is able to mate at about 5 years of age. Mating should happen within 48 hours after the feminine molts, and the process normally lasts a few minutes.

The feminine will spawn her eggs between one month and two years after mating, at which era they change into fertilized by sperm that has been saved.

The variety of eggs the feminine spawns relies on body size, the place an 18 cm lobster will lay about 3,000 eggs, and a 45 cm lobster will lay around 75,000 eggs.

The feminine will then carry the eggs beneath her tail for about 10 to 11 months till they hatch. Only about 1/10 of 1 percent of the younger survive after 4 weeks, primarily attributable to predation.

The younger will transfer concerning the water column for about 12 days, then transfer to the underside.

A feminine lobster carrying eggs on her pleopods. The tail flipper second from left has been notched by researchers to point she is a lively breeding feminine.

Mating solely takes place shortly after the feminine has molted and her exoskeleton remains to be mushy. The feminine releases a pheromone which causes the males to change into much less aggressive and to start courtship, which entails a courtship dance with claws closed.

Eventually, the male inserts spermatophores (sperm packets) into the feminine’s seminal receptacle utilizing his first pleopods; the feminine could store the sperm for as much as 15 months.

The feminine releases eggs by way of her oviducts, they usually move the seminal receptacle and are fertilized by the saved sperm. They are then hooked up to the feminine’s pleopods (swimmerets) utilizing an adhesive, the place they’re cared for till they’re able to hatch.

The feminine cleans the eggs often and followers them with water to maintain them oxygenated. The giant telolecithal eggs could resemble the segments of a raspberry, and a feminine carrying egg is claimed to be “in berry”.

American lobster, Homarus americanus

Since this era lasts 10–11 months, berried females may be discovered at any time of year. In the waters off New England, the eggs are sometimes laid in July or August, and hatch the next May or June.

The growing embryo passes by way of a number of molts throughout the egg, before hatching as a metanauplius larva. When the eggs hatch, the feminine releases them by waving her tail within the water, setting batches of larvae free.

The metanauplius of H. americanus is 1⁄3 in (8.5 mm) long, transparent, with giant eyes and a long backbone projecting from its head. It shortly molts, and the next three phases are related, however bigger.

These molts take 10–20 days, throughout which the planktonic larvae are susceptible to predation; just one in 1,000 is assumed to outlive to the juvenile stage.

To attain the fourth stage – the post-larva – the larva undergoes metamorphosis, and subsequently exhibits a lot larger resemblance to the adult lobster, is around 1⁄2 in (13 mm) long, and swims with its pleopods.

At this stage, the lobster’s claws are nonetheless comparatively small in order that they rely totally on tail-flip escapes if threatened.

After the next molt, the lobster sinks to the ocean flooring and adopts a benthic lifestyle. It molts more and more occasionally, from an initial rate of ten instances per year to as soon as every few years.

After one year it’s round 1–1.5 in (25–38 mm) long, and after six years it could weigh 1 pound (0.45 kg). By the time it reaches the minimum landing size, a person could have molted 25–27 instances, and thereafter every molt could signal a 40%–50% increase in weight, and a 14% enhance in carapace size. If threatened, adult lobsters will usually select to struggle until they’ve lost their claws.

American lobster, Homarus americanus


Although this species just isn’t endangered, conservation efforts have been carried out to protect lobster populations from overfishing.

Laws regulate the size of lobsters taken, which will increase the variety of females reaching sexual maturity and reproducing before being harvested.

Other rules embody limiting the variety of traps set, limits on lobstering licenses, and instances of the year when lobsters are harvested. Another volunteer program carried out is slicing a “V” notch within the tail when a feminine carrying egg is trapped.

She is returned to the ocean and if caught once more just isn’t imagined to be harvested since she is a recognized egg producer.

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