American lobster (Homarus americanus) is an attractive crustacean found on the Northwest Atlantic coast, mainly from North Carolina in the US to Labrador, Canada. Its other common names include Maine lobster, True lobster, Atlantic lobster, Canadian lobster, and Northern lobster.
American lobsters are a part of the crustacean family, which also includes shrimps and crabs. They are an important resource for fisheries along the Atlantic coast of North America, where they are harvested using gear such as lobster traps.
These creatures are cherished by many seafood lovers worldwide for their succulent meat and distinctive flavor. However, they also play an important ecological role as predators and scavengers in their coastal habitat.
Together, let’s explore more about the American lobster’s appearance, habitat, diet, reproduction, threats, and intriguing facts.
Appearance
American lobster’s unique appearance sets them apart from other living arthropod species. For example, they are the heaviest living arthropod species and the heaviest crustacean in the world. They are typically bluish-green to brown, which is a great way to distinguish them from their closest living relative, the European lobster. Some species, especially true and spiny lobsters, are commercially important to humans as food.
Left image credit: Flickr – Patrick Randall; Right image credit: Animalia
American lobsters have a distinct rostrum on the carapace, which covers the head and thorax and provides protection. It must be shed periodically for the animal to grow – a process known as molting. After molting, the lobster has a new shell that hardens over time. During this period, the lobster is vulnerable to predation and often seeks shelter until its new shell hardens.
They possess long, spiny antennae measuring approximately 51 mm long and split into Y-shaped structures covered with nerve cells that sense odors. They also have five pairs of walking legs, with the front two pairs modified into large claws that they use for catching prey and defending themselves from predators. Recreational fishermen catch lobsters in coastal waters with pots and by hand while scuba diving.
Habitat
American lobsters are most commonly found on the Atlantic coast, in the waters around New Jersey, Maine, and North Carolina.
These lobsters prefer rocky shelves and crevices that provide shelter and camouflage from predators like sea urchins and whales. In offshore waters, they are abundant on the ocean floor, down to 1,200 feet.
An adult lobster can dig away sand and gravel from under a rock with their large claws, making a tunnel-like home for themselves. Some of the larger extensive burrows may house two or three lobsters of different sizes. Lobsters may be found from the low tide mark out to depths of approximately 400m.
Although lobsters can be fished in deep waters, high concentrations are found closer to shore in shallower water, like in the southern Gulf of St. Lawrence at depths ranging from 1-40 meters.
Diet & Feeding
American lobsters have a unique digestive system that includes two stomachs. The first stomach, located near the lobster’s mouth, contains a gastric mill with teeth-like features that grind up food. The second stomach is where digestion occurs, breaking down the food particles into nutrients that can be absorbed by the lobster.
Their diet consists of fish, mollusks, algae, and other crustaceans. Mussels are also a common part of the American lobster’s diet.
Using their strong claws, lobsters can pry open the hard shells of mussels to access the soft tissue inside. Once the mussel is opened, the lobster uses its smaller, sharper claw to cut the meat into pieces small enough to swallow. These pieces then pass into the lobster’s stomach for digestion. This ability to feed on mussels and other shellfish contributes to the lobster’s role as a predator in its ecosystem.
They occasionally scavenge on dead animals that have sunk to the seafloor. However, mollusks, clams, worms, and echinoderms dominate their diet across different habitats. These lobsters are also typically nocturnal hunters. So they are great at using their strong sense of smell to locate prey at night.
Reproduction
American lobsters mate after the female has molted and her exoskeleton is soft. The female releases a substance known as pheromone into the water to trigger the males to begin courtship.
Once the two are ready, the male uses his first legs (pleopods) to insert sperm packets into his counterpart’s seminal receptacle.
The egg-bearing females release thousands of eggs through the oviduct that are fertilized by the stored sperm into the water. The eggs are then attached to the female’s abdomen with a sticky substance.
After hatching, the young larvae drift freely with ocean currents before settling on the floor and undergoing a series of molts to become juveniles. This process, known as recruitment, is crucial for maintaining healthy lobster populations.
Lobsters mature into adulthood within 5 to 8 years, but it typically takes around 6 to 7 years for a lobster to grow to the consumable size of 1 pound. It is believed that American lobsters have a lifespan ranging from 50 to 100 years, possibly even longer.
Threats
Young lobsters are more vulnerable to predators than large lobsters because of their soft and less-developed shells.
Bacterial infections like red-tail can cause the death of millions of healthy lobsters within minutes. Epizootic shell disease often causes black lesions on the lobster’s dorsal carapaces. This can reduce their salability and cause deaths.
Conservation of American lobsters is essential due to their ecological role and economic value. Regulations such as size limits, gear restrictions, and protections for egg-bearing females help ensure sustainable harvests.
The lobster’s habitat is also threatened by coast development and pollution from agriculture, industry, and other human activities. Climate change could potentially put lobsters under stress in certain regions while boosting populations in others. However, it also encourages the northward migration of warm-water species.
5 Curious Facts About American Lobsters
- American lobsters are famous for their distinctive claws, which can be used for defense and catching prey.
- These lobsters are not true scavengers but will eat dead animals that have sunk to the deeper water.
- They have a reputation for being unpleasant to eat. Nonetheless, they are considered a delicacy in many parts of the world when cooked properly.
- Two urinary bladders are present in their head region. They use urine to alert other lobsters of their presence and to attract mates.
- The American lobster is not considered endangered or threatened and currently enjoys a stable population.
FAQs
What is the difference between a male and a female American lobster?
Male and female American lobsters can be distinguished by their swimmerets. These features are the small, feathery appendages on their tail’s underside. Males have larger, sturdier swimmerets. On the other hand, females have smaller, softer ones. At the same time, female lobsters have wider tails than males to accommodate their eggs.
Are American lobsters dangerous to handle?
While American lobsters are not inherently dangerous, they can be aggressive and have sharp claws that can pinch if not handled properly. To handle a lobster safely, grasp it firmly behind the claws and avoid putting your fingers or other body parts near its mouth or claws. If possible, avoid taking the risk.
Can American lobsters change color?
Yes, American lobsters can change color depending on their environment and mood. They can range in color from greenish-brown to blue-green to bright red and may turn darker or lighter depending on their surroundings. Some lobsters can also exhibit a bi-colored appearance. In this case, each side of the lobster has a different color.
How do American lobsters differ from other lobsters?
American lobsters are distinguished by their large size, two asymmetrical claws, and a deep greenish-blue to brown coloration, with rare instances of unique colors like blue or albino. European lobsters can appear to be less red in color.
