We invite you to learn all what you ever wanted about these stunning and delicious crustacean called Lobsters.
Lobsters are crustaceans from the phylum Arthropoda, and the decapods order. All of them are marine and benthic and most are nocturnal. They feed on dead and living animals, whether they are small mollusks or other invertebrates that inhabit the sea bottom and seaweed. Some species, especially the true and the spiny lobsters, are commercially important for humans as food. We invite you to read our article types of lobsters, to learn about which of these crustacean are true lobsters and which not.
Table Of Content
- 1 Let’s learn about Crustaceans
- 2 Main Characteristics of the Lobsters
- 3 Lobsters’ Common Behavior.
- 4 Longevity
- 5 Habitat
- 6 How Do Lobsters Reproduce?
- 7 What do lobsters feed on?
- 8 Lobsters as Food
- 9 Hunting and Commercializing Lobsters
- 10 Benefits of Consuming Lobsters.
Let’s learn about Crustaceans
Crustaceans are mostly aquatic arthropods, although there are terrestrial species too. They are named in this way because they are provided with articulated legs made up of different parts. They have very varied forms and we have some 26,000 living species. The common characteristics of the arthropods are their legs and the whole body formed by several segments or somites joined together by means of joints. In this way we have a body constituted by repetitive segments (three in total): head (cephalon), thorax (pereion) and abdomen (pleon). Even, sometimes the first segments or somites of the thorax join the head forming what we will call the cephalothorax. The arthropods have a chitinous external skeleton (the same material of our nails) or exoskeleton which molt periodically, so that they can grow little by little.
Decapod crustaceans are characterized by:
- Presence of ten legs
- Presence of two pairs of antennas, that is, they have a total of four antennas.
- The first three appendages or projections of the second region (thorax) have been developed as mouthparts (for feeding) and are called maxillipeds.
- The appendages or projections of the third region or abdomen are known as pleopods and the last two are called uropods, and between them we find the telson. This set is known as the tail.
For their classification, crustaceans include, in addition to lobsters, shrimp, crabs and prawns. The crustaceans are fundamentally aquatic and inhabit all the depths, both in the marine, brackish and freshwater environments.
Main Characteristics of the Lobsters
Lobsters are invertebrates with a hard protective exoskeleton. Like most arthropods, they need to molt their exoskeleton to grow, which on many occasions makes them vulnerable. During the molting process, several species change color. Three of their five pairs of legs have claws, including the first pair, which are generally much larger than the others. One of their front claws is known as crusher, and they employ it to crush their prey. The other one, is known as pincher, and has serrated blades or teeth and is employed by them to cut or seize their prey. Lobsters employ the other eight pairs of legs to walk. Although they are largely symmetrical bilaterally, like most other arthropods, some genera have unequal and specialized claws.
They have a cephalothorax where the head and thorax are located, covered both by an exoskeleton shell, the abdomen being the other part of their anatomy. Their antennae, jaws, first and second Jaws, and the first, second and third maxillipeds are located in their head. Since they live in shady environments at the bottom of their habitats, they mostly use their antennae as sensors. Their eyes have a reflective structure on a convex retina. In contrast to most complex eyes they use refractive ray concentrators (lenses) and a concave retina. Their tail is made up by the uropod and the telson.
Like snails and spiders, they have blue blood due to the presence of hemocyanin which contains copper, which contrasts with the majority of red blood invertebrates due to the presence of hemoglobin. Their size ranges between 30 and 60 centimeters in length, although the vast majority does not measure more than 40 centimeters. As for their weight, it is seldom greater than 1kgm, although male specimens have been found of up to 12kgms weight.
Differences between Males and Females.
The lobsters are unisexual, that is to say there are males and females, whose main difference lies in the location of their genitals and in their form. The females’ last two legs have bifurcated shape, while males have fingernails at the end of each thoracic leg and their sexual orifice is at the base of the fifth row of the thorax legs. On the other hand females have a narrower head and a wider tail that allows them to lodge the clusters of eggs after mating.
Let´s meet them better
Lobsters’ Common Behavior.
Lobsters are characterized by developing nocturnal habits during their adulthood. They also develop migratory habits in times of cold. When winter comes, they usually swim 250 meters or even more, to get in warmer waters at the bottom of the sea. In times of heat they live in depths varying between 20 to 70 meters. They are nocturnal animals, and during the day they remain as motionless as possible so that their predators do not see them. In the evenings they roam the surface of the habitat where they live to look for food. They usually prefer that their environment has some coverage that they can use to protect themselves from predators. They are found in coral and artificial reefs , between mangrove roots. They can also be found near man-built structures such as docks or wooden bridges.
Lobsters live between 45 and 50 years when they remain in their natural habitats. Several researches suggests that they don´t lose their skills when they age in terms of speed, strength and fertility, and even older lobsters can be more fertile than the younger ones. This longevity is due to an enzyme called telomerase, which is common in most crustaceans during embryonic stages, but is usually absent during the adult stages of their lives. However, such enzyme is present in most of the lobsters’ tissues during their adult stage.
How does it work?
The cells make up all living creatures on Earth, from humans to lobsters. However, cell replication is limited depending on nucleotide sequences called telomeres that are found at the ends of chromosomes. In short, telomeres prevent the DNA strands from unraveling and also prevent them from accidentally fusing with neighboring chromosomes. The problem is that these end caps are shortened each time the cell divides due to the fact that the enzymes that duplicate the DNA, with a little help from short fragments of RNA, can not do so until the end of a chromosome. Then, something is cut every time a replication occurs. Telomeres make sure that what is cut is not critical information. But the result of this reduction every time is that the telomeres become too short to provide an adequate buffer. For reference, human cells can only replicate between forty and seventy times before the telomeres become too short. This leads to the cell can no longer replicate correctly and cell death. The lobster cells work a little differently.
The body of a lobster produces amounts of the telomerase enzyme even in adulthood. While humans and other vertebrates also produce telomerase, our bodies only (generally) produce it while they are in embryonic form. What does telomerase do? It continuously repairs the telomeres of the cells, preventing them from becoming too short. The result is that the DNA in the cells can continue to replicate indefinitely, so it is often claimed that lobsters are technically «immortal.» The bigger a lobster, the greater its age. However, moulting consumes more and more energy as the lobster increases in size and the amount of effort required by a lobster from 30 to 50 years to molt, kills between 10% and 15% of the lobsters each year. But just because lobsters can potentially keep growing and molting until their death, doesn’t mean they always do, even if they have enough food available and ideal environmental conditions. It has been observed that the old lobsters stop molting completely, with the theory that their bodies simply do not have the ability to do so, probably because of the lack of the necessary metabolic energy.
Just as an elderly human being is often more susceptible to things like pneumonia for several age-related reasons, this is a major problem for lobsters as it often leads to a shell disease, a bacterial infection in the shell that can create a scar tissue between the lobster and the shell. If they are able to molt again later, they have the problem that scar tissue adheres to the inner body and shell, which can cause the lobster to bind and die. Shell disease can also lead to other problems, such as rotting the shell, being the net effect the same: the lobster that no longer moults.
So how long do lobsters live before they die for this kind of natural causes? According to the biologist Carl Wilson of the Department of Marine Resources of Maine , «The problem with lobsters is when they molt, they change their exoskeleton completely, including their digestive tract and gastric mill and the like, so there are no remaining hard parts, « Leaving little in the way of measurable physical markers accurately. Even judging by size is not fool proof because of a variety of environmental factors that greatly influence their growth rate. But for reference, using several different means to try to judge the age of the lobsters it is believed that the average lifespan in the natural habitat of the various types of lobsters is about thirty years for the males and of about fifty or sixty years for the females.
Lobsters live in all oceans, on rocky, sandy or muddy bottoms from the coast to beyond the edge of the continental shelf. In general, they live alone in crevices or in burrows under rocks. They usually walk slowly on the bottom of their habitats. However, when they flee, they swim back quickly at a speed of 5 m / s (11 mph), curving and unscrewing their abdomens for that purpose. This is known as the caridioid escape reaction.
How Do Lobsters Reproduce?
Lobsters only mate after the females molt their exoskeleton. Before this process, the female releases pheromones (chemicals) into the water, so that nearby males know that she is preparing to molt and mate. If there are several males interested in her, they will fight each other to determine which of them mates. The winner takes the female to his cave and protects her from any predator, since she is quite vulnerable when she molts her exoskeleton. When the molting process has culminated, the male gently turns her over and pierces her abdomen with his first pair of pleopods, depositing his sperm in the female’s sperm receptacles.
The male’s reproductive fluid usually stays up to 15 months in the female. When the female considers it to be the right time, she releases her eggs to be fertilized by the sperm stored in her. The female then fixes the eggs, (around 5000, or even 10000 in some cases) under her tail, where they remain for the next 10 or even 15 months. During this time the female lobsters are commonly called berried, because the eggs look like small berries. When the eggs hatch, baby lobsters look like adult lobsters. They are rather small larvae, which will molt four times before they begin to show any resemblance to an adult lobster.
During their larval stage the lobsters float on the surface of the ocean. Most of them don´t survive this stage of their lives, because they are devoured by other marine species or even by other lobsters. Once the small lobsters have passed the early larval stages, they move to the ocean bed to find protection in algae and rocks. There, juvenile lobsters will remain hidden until they are large enough to fight predators.
Let´s watch them molting their exoskeleton
What do lobsters feed on?
Lobsters like to eat crabs, clams, mussels, starfish, smaller fish, and sometimes even other lobsters. Their mouth is located just below the cephalothorax, which is in the middle of the antennae. They have jaws that they use as teeth to make a first chewing. These foods are taken to the first stomach called cardiac stomach, where they are ground. After this they reach the second stomach, called Pyloric where they finally pass into the intestine. Some experts call them sea cockroaches, because they can also eat the waste of other animals as well as dead fish in the depths of the sea.
If after traveling around some distance they don´t find their food, they dig in the surroundings areas in search of clams, algae and small fish that live among the algae. They are also fervent hunters of slower species like snails, to which they break the shell with a single blow using their claws. They can also eat crabs if they get them. What most highlights of the lobsters is their huge adaptability to different environments and food, surviving even in captivity, where they need a huge variety of vegetables, such as spinach, carrots and zucchini.
Lobsters as Food
Lobster recipes include Newberg Lobster and lobster Thermidor. They are commonly used in soups, creams, lobster rolls and lean. Their meat when mixed with clarified butter, results in an accentuated and delicious flavor. They are usually cooked while still alive, a fact that has unleashed a lot of controversy, due to the huge pain they suffer. In fact, since this year in countries like Switzerland and New Zealand this practice has been banned, and it has been established that lobsters must be stunned electrically before being cooked. In some other countries this law is about to be applied.
Therefore we should not worry about missing this exquisite dish on our tables, always remembering that to maintain our planet´s biodiversity, it is best to take a balanced diet without abusing of the consumption of a particular species.
Hunting and Commercializing Lobsters
In the Florida Keys, the American lobsters, Homarus americanus, compete with shrimps in terms of commercial value, in addition to being the main food exported to the Bahamas. They are hunted for both human consumption and sports by professional divers. The hunting season of this animal extends from the months of August to January. Before starting the official fishing season there is a recreational season for divers, winning even prizes for the best fishing. The divers can take the lobster with their hands, with the help of a glove and a block or stick.
How are the Lobsters Hunted?
Commercial fishermen hunt this animal using traps, which are basically huge cages made of frame and covered with galvanized wire in turn covered by plastic. This is a very similar method to the one used in New England. These traps are baited with dead fish or chicken necks, in order to attract the lobsters with their smell. The traps are set on the bottom of the sea during the night. During the morning the fishermen find the traps with the help of a buoy, and take them out using an engine.
Once out of the water, they put the animals in water tanks inside the fishing boats, and then proceed to measure them, releasing the specimens that have not reached the legal size that is 8.25 centimeters at least. Then they put bait in the trap again, to repeat the whole process. The lobster is placed in a compartment inside the boat, and then passed to a wooden box. This box is moored to a buoy at a dock near the city. Then when they are already bought, they are passed to drawers that are covered with sacks to take them to their final destination.
The traps are made in such a way that they have a funnel-shaped entrance, so when the lobsters reach the end, they enter into a compartment from which they cannot leave afterwards. However, they have openings on the sides, which allow the young lobsters that don´t have the catching legal size, get out of the trap. Although it is illegal in Florida, in the Bahamas and the Caribbean it is allowed to fish lobster using harpoons.
According to the FEDECOOP (Regional Federation of Cooperative Societies of the Baja California Fisheries Industry, F.C.L), lobster hunting has an annual average of 1400 tons. Most of the export is sent to Asia. A small amount is sent to markets in France and the United States. Only 10% of the total catch is sold locally in the Gulf of Mexico. While the hunting season is open, the lobster is sold and distributed while alive, being packed in 10-kilo boxes where they are kept frozen, so that they can resist the trip along the ocean liner. During the closure, as long as the product is available, the lobster is sold frozen. Also at this time, it is possible that the lobster is cooked whole steamed, to sell then under special order, only the tails. Lobsters in three different types of presentation can be acquired: live lobster, frozen raw lobster and frozen cooked lobster. Generally the sizes vary between the small lobster weighing between 1 1/2 and 1 3/4 pounds and large lobsters whose weight varies between 1 3/4 of a pound or more.
Social Change in Lobsters´ Consumption
Maybe nowadays, saying that you are going to eat lobster ignites the envy of some of your friends, since it is considered a luxurious and ostentatious dish. The luxury of this animal not only resides in its great flavor, but also on its high price, which keeps it away from the table of those who have few resources. Curiously, this was not always the case, and its social escalation is considered one of the most extreme changes of image, that have occurred in the history of food and products.
When the first European settlers arrived in North America, there were so many lobsters on the Atlantic coasts of Canada and New England, accumulated on the shores of the beaches, forming piles that reached the knees of the settlers. Due to this abundance, the lobster became a hindrance for fishermen who wanted to go into the sea to catch fish, often considering them an undesirable animal. The settlers started feeding pigs, cows and cats with these crustaceans.
In addition the lobster was considered food for poor people, and was used by the wealthiest community to feed the prisoners and the serfdom. After a while the prestige of the lobster fell so much that the servants rebelled, getting to establish a clause in the job´s contracts, which stipulated that they would not be fed with lobsters more than three times a week. If lobster shells were seen in a house, it was considered a house of resourceless people with great social degradation.
Reaching the Riches Tables.
You are probably wondering how lobsters had such a drastic change in the consumers´ appreciation. They became a privileged dish, thanks to the appearance of canned products and the railway in the late nineteenth century. The first canned factory in the United States was established in Maine in the year 1841 and although at first it was difficult for stores to buy canned food, people living in the center of the country had at last a direct and cheap access to the lobster. But what really elevated their category of Kings Food served with butter and herbs, were the tourists. The employees who were on the railways realized that the passengers didn´t really know the reputation of the lobster, so they could offer it as a delicacy professed to the diners a real delight. This practice was popularized by restaurants describing the crustacean as a splendid food, offering it to high-class tourists who visited Maine from the south, eager to meet the sea and its exotic delicacies. Returning home, the elegant tourists wanted to continue testing the lobsters´ delicate taste, and described to their friends and family the delights offered by Maine through their dishes. When refrigeration arrived in states, the lobster took an even bigger step, as they began to distribute them alive in more distant places like England and diverse markets where their value was multiplied by ten.
The highest point in the price of the lobster, was reached in the 20s, however the great Depression that went through America caused the animal to lower its value again. By the end of the 50s, which were times of high economic prosperity, lobster consolidated as a dish for the royalty. It was a sort of exclusive meal for the rich people and Hollywood stars, maintaining its reputation over the years.
In spite of all the glamour that the lobsters represent, it may be that it is descending again in the social scale. This decline is due to a bonanza that occurs mainly in North America. As a result, there are restaurants that are venturing to offer lobsters on their menus, which previously would have seemed unthinkable. A clear example of this, is that fast food chains like McDonald’s are experimenting with this crustacean. According to Adam Leyland, considered an authority in the food industry and online editor of the publication «The Grocer,» «the product is being democratized.» Of course, the increase or decrease in the lobster price directly influences the rule of supply and demand.
In the United States, the value of this product can rise without limit, because it is not regulated by any price structure that has been imposed by the government, unlike other products such as corn, wheat and meat. But despite the lack of regulation, the price of lobster can also fall precipitously. According to the food historian Polly Russell, the decline in the price is mainly due to the accelerated reproduction that the animal has had, as a consequence of the climate change. In addition to this, the cod population which is its main predator; has decreased due to its big consumption.
Benefits of Consuming Lobsters.
Many studies have shown that the consumption of fish and shellfish decreases the risk of obesity, diabetes and heart disease, while promoting healthy cholesterol levels. Fish and shellfish, such as lobster, are especially important to provide Omega-3 fatty acids, which are found in very few foods. It is estimated that a three ounce serving of spiny lobster provides 200 to 500 milligrams (mg) of Omega-3. As for the American Lobster it provides 200 mg in a portion of the same size. Although the content of fatty acids in lobster is not the highest among fish and shellfish, it remains a considerable source of these important nutrients. We invite you to read our article common tuna to learn more about the sea food benefits
Bon appétit again