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The American lobster, Homarus americanus, is one species of lobster found on the Atlantic coast of North America. Within North America, it is also known as the northern lobster, Atlantic lobster or Maine lobster. It thrives in cold, shallow waters where there are many rocks and other places to hide from predators and is both solitary and nocturnal. It feeds on fish, small crustaceans, and mollusks.
The American lobster is found as far south as North Carolina, but is famously associated with the colder waters around the Canadian Maritimes, Newfoundland and Labrador, Maine, Massachusetts, Rhode Island and New Hampshire. They commonly range from 8 to 24 in (20 to 61 cm) in length and 1 to 9 lb (0.5 to 4.1 kg) in weight, but have been known to reach lengths of well over 1 yd (1 m) and weigh as much as 44 lb (20 kg) or more, making this the heaviest marine crustacean in the world. An average adult is about 9 in (230 mm) long and weighs 1.5 to 2 lb (680 to 910 g).
The adult American lobster's main natural predator is the codfish, but other enemies include haddock, certain species of seals, flounder, and other lobsters. Overfishing of cod in the early 20th century has allowed the lobster population to grow enormously.
American lobsters molt two to three times per year while juvenile, but only once a year or less when fully mature (which is about four to seven years old). When a lobster nears its next shedding period, it starts to grow a new shell underneath the current one, and the outer shell becomes very hard and darkens. The line that runs along the back of the lobster's carapace begins to split, and the two halves of the shell fall away. Claws and tail pull out from the old outer shell, as the inner shell is very malleable. The old shell is often eaten for calcium recovery and the leftovers are sometimes buried.
Females usually mate right after molting, but mating in between molts, known as intermolt mating, can occur. Larger females can store sperm for several batches of eggs from a single coupling. All females store the sperm to fertilize eggs later, not at the time of copulation. While getting ready to molt the female finds the den of a suitable male and visits it several times. When finally ready to molt, the female does so in that den. After the molt the male waits for the shell to start to harden, gently stroking the paper thin new shell with his large antennae. After several minutes the male rises on his claws and tail, and uses his legs to flip the female over and get on top. The male has a pair of hardened swimmerets, or fins on the bottom, that match a pair of swimmerets on the female that have an opening between them. The sperm, contained in a gelatinous blob called a spermatophore slides down notches in the male's swimmerets into the female. The outside end of the spermatophore hardens to block the hole. The receptacle on the female is part of her shell so she must use the sperm before her next molt or lose it. The male dismounts, and then may eat the female's shell. The female stays in the den for several days while her shell hardens more. Lobsters do not mate for life, contrary to some myths. The female seeks the most alpha male she can find, and the male mates with as many females as he can.
In the first two weeks after molting, lobsters are very vulnerable, as their shells are so soft they can neither move very fast nor defend themselves with their claws. (At this point, they are often referred to as "shedders" in the industry.) They often fall prey to other lobsters, especially egg-bearing females, who become defensive when carrying eggs.
Because lobsters molt, it is extremely difficult to determine a lobster's age. Many lobsters live up to 50 years.
The eyes of these lobsters are different from almost all other animals. Rather than using lenses to focus light on sensitive cells, narrow tapered channels lined with a crystalline material reflect the light onto the retinal cells. This same design is proving useful for focusing x-rays and other hard to refract light — as in the namesake Lobster-ISS x-ray telescope.
The antennae measure about two inches long and split into Y-shaped structures with pointed tips. Each tip exhibits a dense zone of hair tufts staggered in a zigzag arrangement. These hairs are covered with multiple nerve cells that can detect odors. Larger, thicker hairs are found along the edges. These hairs control the flow of water, containing odor molecules, to the inner sensory hairs.
The shorter antennules provide a sense of smell. By having a pair of olfactory organs, a lobster can locate the direction a smell comes from, much the same way humans can hear the direction a sound comes from. In addition to sensing smells, the antennules can judge water speed to improve direction finding.
The lobster's mouth is used for more than eating. For burrowing it can be shaped into a wedge and used to push gravel and sand, and used to carry small rocks away. A lobster can even pull itself around by its mouth, if it has lost both claws and all legs by fighting.
A lobster actually chews its food in its stomach, rather than its mouth. Food is chewed between three teeth-like grinders in what is called the gastric mill.
Legs and claws
At first, a lobster's claws are identical, but with use the lobster starts to favor one over the other. The favored claw gets bigger and fills with primarily slow-acting muscle tissue that cannot react quickly, but has more stamina. This is the crusher claw. The other claw, the pincher, develops fast-acting muscle tissue useful for grabbing prey. During lobster to lobster fights, one typical move is claw lock where the two lobsters grab each other's crusher claw and have a showdown of muscle and shell strength.
Lobsters have not one, but two urinary bladders, located on either side of the head. Lobsters use scents to communicate who and where they are, and those scents are in the urine, as in dogs. But while a dog just marks places, lobsters have strong muscles to project long (up to 1½ m) plumes of urine in front of them and do so when they detect a rival or a potential mate in the area. Lobsters also urinate continually while at the doors of their hiding places to indicate who is inside.
The eggs are bright orange, and very small, about 1 mm (0.039 in) in diameter. They are carried by the female on the underside of the tail for a period of 8–12 months , whereupon they are released over several days and hatch. The number of eggs carried by a single female can range well into the tens of thousands, but the survival rate is very low, speculated at around 0.1%. Older females produce vastly more eggs than younger ones. In one observation (Francis Herrick, in the 1890s) 5 in (13 cm) females were found to have about 4,000 eggs, while 10 in (25 cm) ones produced about 50,000 eggs.
Eggs and newly hatched lobsters can be carried very long distances by ocean currents. Within the egg lobsters molt thirty-five times. At the time of hatching, the larva still looks more like a shrimp than a lobster. For several weeks, the larva floats near the surface of the sea, eating and growing. It has small fins that allow some movement, but not real swimming. The final juvenile stage, the postlarva stage, has been called the "superlobster" by some. It is the only time in a lobster's life that it can swim forward, an act that bears some resemblance to Superman flying. At this age the lobster is about .8 in (2.0 cm) long. This stage lasts a week or two, during which the lobster swims during the day, at speeds of up to 8 in (20 cm) per second — fast enough to cover 6 mi (10 km) per day. The superlobster seeks a rocky bottom with good hiding places. This way its predators cannot attack it. Without anywhere to hide it quickly falls prey to small fish, such as sculpin and cunner.
Red lobsters are the usual result of a lobster being cooked. However according to the Gulf of Maine Institute there is a 1 in 10 million chance of catching one alive with that color. Most lobsters are colored a mottled dark greenish brown, and are usually a mixed pigment of yellow, blue, and red.
It is estimated that around one in 2–5 million lobsters are blue. A genetic defect causes a blue lobster to produce an excessive amount of protein. The protein, and a red carotenoid molecule known as astaxanthin, combine to form a blue complex known as crustacyanin, giving the lobster its blue color. According to the New England Aquarium, while blue lobsters are rare, they are not unheard of; in 2009 a blue lobster was caught in New Hampshire by a fisherman who thought he had caught a shiny blue beer can.
Yellow lobsters are the result of a rare genetic mutation and are very rare with the odds of finding one at 1 in 30 million. While the exact number of catches is unknown the following examples made headlines with two of the catches being preserved.
On June 11, 2009, a yellow lobster was reported by The Boston Globe as having been caught off the coast of Prince Edward Island, Canada, by Michael R. Gagne, sales manager at Ipswich Shellfish Company, Inc. The lobster was given by Mr. Gagne to his friend Nathan Nickerson of Arnold's Lobster and Clam bar in Eastham, Massachusetts. Nickerson named the rare yellow lobster "Fiona" in honor of his girlfriend's granddaughter and intends to keep the animal as a pet before possibly donating it to either the Cape Cod Museum of Natural History in Brewster or the New England Aquarium.
On April 30, 2010, a yellow lobster named "Leilani" was discovered in a shipment in Wainani Kai Seafoods in Kalihi, Hawaii. The shipment arrived from Nova Scotia, Canada. Employees quickly spread the word on the rare creature. Wainani Kai Seafoods called the Waikiki Aquarium to take a look at the female lobster. Four days later, the lobster is now in the hands of employees from Waikiki Aquarium. The Aquarium staffers will quarantine the lobster first; then they will build a special display for the lobster.
It was also reported in July 2010 that an albino lobster was caught in Gloucester. It is estimated that only about one in 100 million lobsters is albino — lacking in colored pigments. These are also referred to as "white" or "crystal" lobsters due to their metallic appearance.
On July 13, 2006, a Maine fisherman named Alan Robinson caught a half-and-half lobster, where the colors are perfectly divided on each side of the shell. He submitted the brown and orange lobster to the local oceanarium, which has only seen three lobsters of this kind in 35 years. The chance of finding one is estimated at 1 in 50 million. Lobster shells are usually a blend of the three primary colors: red, yellow and blue. The colors mix to form the greenish-brown color of most lobsters. All split-colored lobsters observed by Bob Bayer of the Lobster Institute in Maine have been hermaphroditic.
On August 28, 2010 it was reported that a rare calico lobster was caught in Maine with a mottled orange and black shell. Diane Cowan, a lobster scientist and founder of the Lobster Conservancy in Friendship stated that only albino lobsters are more rare and also orange lobsters such as these are a 1 in 30 million catch.
American lobsters as food
American lobsters are a popular food. They are commonly boiled or steamed; for either method, keeping them alive until they are cooked can help avoid food poisoning, but frozen and refrigeration storage methods are also very common, and safe. Hardshells (lobsters that are several months past their last molt) can survive out of water for up to two days if kept refrigerated. Softshells (lobsters that have only recently molted) do not survive more than a few hours out of water. Because of this requirement, they can often be selected out of the tank in many restaurants, and their cost also can vary seasonally. Lobsters are usually cooked alive, which causes some to refuse to eat them believing such treatment inhumane.
Lobster on its own is very low in fat but not suitable for low sodium diets. Lobster tail usually comes from different varieties of lobsters. The 'tail' of a lobster tail, is not actually a tail but the abdomen, called a telson. One common way of serving lobster tail is with beef. This is known as surf and turf. Lobsters have a greenish or brownish organ called the tomalley that performs the functions of the liver and pancreas in a human, i.e., it filters out toxins from the body. Some diners consider it a delicacy, but others avoid it because they consider it a toxin source or dislike eating innards.
Most lobsters before cooking are mottled in appearance, but after cooking, almost all of them are completely red. Caution is advisable, as much of the body still contains water, which may stay hotter than the outside of the shell and can scald an inexperienced diner.
A set of nutcrackers and a long, thin tool for pulling meat from inaccessible areas are suggested as basics, although more experienced diners can eat the animal with their bare hands or a simple tool (a fork, knife or rock). Eating a lobster can get messy, and most restaurants offer a lobster bib.
Meat is generally contained in the larger claws and tails, and stays warm quite a while after being served. There is some meat in the legs and in the arms that connect the large claws to the body. There is also some small amount of meat just below the carapace around the thorax and in the smaller legs. The meat is generally sweet and tender. Dipping chunks of the meat into melted butter is often done to enhance its taste.
North American lobster industry
Most lobsters come from the north-eastern coast of North America with the Canadian Maritimes and the US state of Maine being the largest producers. They are caught primarily using lobster traps, although lobsters are also harvested as bycatch by bottom trawlers, fishermen using gillnets, and by scuba divers.
Lobster traps are rectangular shaped cages made of vinyl-coated galvanized steel mesh with woven mesh entrances and traps of the same design made of wood. These are baited and lowered to the sea floor. They allow a lobster to enter, but make it difficult for the larger specimens to turn around and exit. This allows the creatures to be captured alive. The traps, sometimes referred to as "pots", have a buoy floating on the surface and lobstermen check their traps anywhere between one to seven days later. The inefficiency of the trapping system has inadvertently prevented the lobster population from being overfished. Lobsters can easily escape the trap, and will defend the trap against other lobsters because it is a source of food. It has been estimated that only 10% of lobsters that encounter a trap enter, and only 6% will actually be caught.
In the United States, the lobster industry is regulated by law. This is done to protect the lobster industry for future generations. Every lobsterman is required to carry a lobster gauge. This is a measuring device that gauges the distance from the lobster's eye socket to the end of its carapace. If the lobster is less than 3¼ inches (83 mm) long, it is too young to be sold and must be released back to the sea. Dishonest lobstermen could try to sell these "shorts." There is also a legal maximum size of 5 inches (127 mm) in Maine, meant to ensure the survival of a healthy breeding stock of adult males, but in parts of some states, such as Massachusetts, there is none. Also, traps must contain an escape hole or "vent", which allows juvenile lobsters and by-catch species to escape. Law in Maine and other states dictates that a second large escape hole or "ghost panel" must be installed. This hole is held shut through use of biodegradable clips made of ferrous metal. Should the trap become lost, the trap eventually opens, allowing the catch to escape.
To protect known breeding females, lobsters that are caught carrying eggs are to be notched on a tail flipper (second from the right, if the lobster is right-side up and the tail is fully extended). Following this, the female cannot be kept or sold, and is commonly referred to as a "punch-tail" or as "v-notched". These egg-bearing females are also known as "scrubs", since an unscrupulous lobsterman may scrub the eggs off the underside of the tail with a stiff brush and attempt to sell the lobster as an honest catch. The United States Coast Guard often boards the boats of lobstermen to ensure that they are not carrying "shorts" or "scrubs".
The commercial lobstering industry is largely self-regulated. There have been well-documented examples of 'ocean justice' where dishonest lobstermen have lost their boats, homes and vehicles to vandalism by other lobstermen in retaliation for illegal acts such as scrubbing, selling shorts or hauling another lobsterman's pots. In the past, many lobstermen would keep firearms aboard their vessels to threaten any boaters or other lobstermen who were seen hauling their pots. This practice continues in many parts of New England. The laws of Massachusetts and several other states permit lobstermen to use force to protect their pots.
Lobster management policy in the US is made by committees called LCMT's or Lobster Conservation Management Committees. These groups are made up of local fishermen, policy managers and scientists. The LCMT's report to the Atlantic States Marine Fisheries Commission, an interstate fisheries organization. Lobstermen are unique in the US in that they are able to create their own conservation policy, as set under specific guidelines by scientists and political management.
Lobster boats range from small rowboats to the larger 80+ ft offshore boats that fish the US EEZ from Maine to North Carolina. The average inshore lobster boat is anywhere from 25 to 42 ft (8 to 13 m) long. These inshore boats haul anywhere from 200-500 traps each day.
An inshore lobster boat costs anywhere from US$30,000 to $400,000, depending upon the size of the boat and engine. Lobster traps cost anywhere from $50–80 each, and most lobstermen fish 400-800 traps (800 is the maximum number of traps allowed lobstermen in the inshore Gulf of Maine). In addition, the rope and buoys used are also very expensive.
In the late 1990s and early 21st century, lobster fishing was the cause of troubles between Acadians and Mi'kmaq First Nations in the Canadian Maritimes. The Acadian economy (and identity) relied substantially on fisheries, especially lobster. In 1998, the Supreme Court of Canada ruled in favor of the First Nations and granted them unlimited rights to natural resources. The decision was based on a treaty from the 18th century. The federal government attempted to take licenses and quotas from the traditional fishermen and hand them out to the natives, which caused great upset among Acadian fishermen, whose fishing quota had already dropped dramatically in the years before. The hub of these troubles was Burnt Church, a reserve between Miramichi and the Acadian town of Neguac, in the heart of a region where white people are just as poor as Natives. White fishermen had cut the buoys off Native-owned lobster traps, causing the lobster traps to be lost and become a hazard to marine life. A Royal Canadian Mounted Police ship nearly sank a Native ship.
The tension increased and decreased with each fishing season. Its climax came in April 2003 when a riot broke in the port of Shippagan. Three native-owned fishing ships and a fish processing plant were burnt down. Since then, efforts have been made to bring Acadians and Natives closer together and the tension has slowly come down.
American lobster tends to have a stable stock in northern (colder) waters, but gradually decrease in abundance moving southward. To manage lobster populations, more regulations and restrictions, geared towards achieving sustainable populations, are implemented gradually southward.
Like all organisms, lobsters are susceptible to diseases. These can be both infectious and non-infectious. Neoplastic (cancerous) diseases of lobsters are few if any.
Paramoebiasis is an infectious disease of lobsters caused by infection with the sarcomastigophoran (amoeba) Neoparamoeba pemaquidensis. This organism also causes amoebic gill disease in farmed Atlantic Salmon, Salmo salar. Infection occurs throughout the tissues, causing granuloma-like lesions, especially within the ventral nerve cord, the interstices of the hepatopancreas and the antennal gland. It is strongly suspected that paramoebiasis played a prominent role in the rapid die-off of American lobsters in Long Island Sound that occurred in the summer of 1999.
Gaffkemia or red-tail is an extremely virulent infectious disease of lobsters caused by the bacterium Aerococcus viridans. It only requires a few bacterial cells to cause death of otherwise healthy lobsters. The "red tail" common name refers to a dark orange discoloration of the ventral abdomen of affected lobsters. This is, in fact, the haemolymph or blood seen through the thin ventral arthrodial membranes. The red discoloration comes from astaxanthin, a carotenoid pigment exported to the blood during times of stress. The same sign is also seen in other diseases of lobsters and appears to be a non-specific stress response, possibly relating to the anti-oxidant and immunostimulatory properties of the astaxanthin molecule.
Systemic infections by the bacterium Vibrio fluvialis (or similar organisms) are reported to cause "limp lobster disease", wherein lobsters become lethargic and die.
Excretory calcinosis in American lobsters in Long Island Sound was described from an epizootic in 2002. It is a disease that causes mineralized calculi to form in the antennal glands and gills. These cause a loss of surface area around the gills and the lobster eventually asphyxiates. Several reasons have been proposed as to what has caused a recent outbreak of the disease. The most generally attributed factor is an increased duration of warmer temperatures in the bottom of the Long Island Sound.
According to Guinness World Records, the heaviest crustacean recorded was an American lobster caught off Nova Scotia, Canada, weighing 44.4 lb (20.1 kg) and having a length of 3.51 ft (1.07 m).
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