Educational Resources
Lobsters and the lobstering industry provide a wealth of opportunities for learners of all ages. Whether it is the culture and folklore surrounding lobsters and lobstermen; the economics of the industry; or the process of passing laws and regulations to manage the fishery…the American lobster, and the people and industry that surrounds it, can teach us a great deal.
Lobsters are complex creatures. Click the tabs above to learn more.
Body Parts
Nervous System
Invertebrates such as lobsters and insects do not have complex brains like vertebrates such as fish, birds, reptiles, or mammals do. Instead, lobsters contain 15 nerve clusters called ganglia dispersed throughout their bodies, with a main ganglion located between their eyes. Each ganglion helps to control and process sensory information in a different segment of the lobster’s body. Whether these ganglia allow them to feel pain, though, is still somewhat contested. Studies have shown they do contain nociceptors- nerves that allow the processing of noxious stimuli; however, this does not necessarily mean lobsters feel pain in the way we understand it, as pain is a subjective experience. Researchers have debated for many years whether animals without true brains have the complexity or capacity to experience pain in the way we understand it and will likely continue to debate this point for years to come as well.
Circulation
A lobster’s blood is usually greyish/clear in color. It is circulated by a heart located just behind the stomach, through a few large blood vessels. It picks up oxygen from the water through the gills, found in the lobsters’ thorax section.
Female lobster
A female lobster mates primarily when she is in the soft-shell state, right after she has shed her shell (molted). The photo to the left shows an egg-bearing lobster, also known as a “berried” lobster.
Eggs
A freshly laid lobster egg is the size of the head of a pin (1/16″). A 1-pound female lobster usually carries approximately 8,000 eggs. A 9-pound female may carry more than 100,000 eggs. The female lobster carries the eggs inside for 9 to 12 months and then for another 9 to 12 months, externally attached to the swimmerets under her tail by a glue-like substance. When the eggs hatch, the mother releases them by fanning her swimmerets.
Larval Stage
Now in the first larval stage, the newborn lobsters will float near the surface for 4 to 6 weeks. They are very susceptible to prey during this stage and will go through three molts or stages.
Post-Larval Stage
After the fourth molt the few that survive will settle to the bottom; look for hiding places in rocks, grassy areas, etc. and continue to develop as post-larval lobsters. For every 50,000 eggs, only about two lobsters are expected to survive to legal size.
Juvenile Lobsters:
As the lobsters grow, they become more adventuresome and hide less. Their habits are similar to adult lobsters. It takes 5 to 7 years for a lobster to grow to the legal size to harvest. A lobster at minimum legal size will weigh approximately 1 pound. (Based on Maine’s legal minimum of 3 1/4″ carapace size. Legal sizes can vary by state/country.) Juvenile lobsters can molt as many as 25 times before reaching adulthood. See the photo of juvenile lobsters on the right.
Adult Lobsters:
Lobsters reach adulthood after 5-8 years. As adults, males typically shed or molt once a year, and females once every two years.
Molting:
Lobsters grow by molting. This is the process in which they struggle out of their old shells while simultaneously absorbing water, which expands their body size. After molting, lobsters will eat voraciously, often devouring the shells they just shed. This replenishes lost calcium and hastens the hardening of the new shell.
Click for links to molting photos and videos.
This molting, or shedding, occurs about 25 times in the first 5-7 years of life. Following this cycle, the lobster will weigh approximately one pound. After this time, the lobster may then only molt once per year (males) or once every two years (females). At this point, with each molt, the lobster will increase about 15% in length and 40% in weight. No one has yet found a way to determine the exact age of a lobster. However, based on scientific knowledge of body size at age, the maximum age attained may approach 100 years. Lobsters can grow to be 3 feet or more in overall body length.
Habitat
Lobsters are benthic, living on the bottom of the ocean. They prefer temperatures from 15-18°C (59-64°F) and salinities of 20-25 ppt. The American lobster can be found on the east coast of North America, from Newfoundland to North Carolina. Small lobsters (less than 1.5″ carapace length) are very cryptic, hiding in and about sea weeds and rocky habitat that provide adequate food and shelter from predators. Adolescent lobsters (1.5″ – 3.5″ carapace length) dominate coastal habitats and offshore areas. They generally exhibit minimal migratory behavior. Larger, more mobile, adult lobsters may inhabit deeper waters but return seasonally to shallow, warmer waters.
Lobster Fishing
Commercial lobster fisheries are found in the North Atlantic from the Long Island Sound areas of New York & Connecticut up to Newfoundland. About 60% of North American lobster landings are in Canada and 40% in the U.S. Maine lands approximately 80% of the U.S. catch, followed by Massachusetts at 18%.
Diet
Lobsters usually move around and hunt for food at night. It was once thought that lobsters were scavengers, and ate primarily dead things. However, lobsters are really more opportunists, catching mainly fresh food which includes fish, crabs, clams, mussels, sea urchins. Lobsters are also cannibalistic and sometimes will eat other lobsters. Baited traps also supply food for lobsters. Traps were traditionally baited with salted fish — usually herring. Juvenile lobsters can move freely in and out of lobster traps, and adults can also move in and out of the traps. Thus, many feel bait provides a substantial source of food for inshore lobsters.
Eating & Digestion
Lobsters “smell” their food by using the four small antennules on the front of their heads and tiny sensing hairs that cover their bodies. A lobster will use its crusher claw to break open shellfish and its ripper claw to tear food apart. The two sets of walking legs (or pereiopods) immediately behind the claws are also used for catching and eating food and have many “taste” sensors. They are used to move food into the mouthparts or maxillipeds. The teeth of the lobster are in its stomach. The stomach is located a very short distance from the mouth, and the food is actually chewed in the stomach between three grinding surfaces, called the gastric mill, that look like molar surfaces.
Classification
Lobsters are classified in the phyllum Arthropoda (which also includes shrimp, crabs, barnacles, and insects.) The word Arthropoda comes from the Latin word “arthro”, meaning jointed, and the Greek word “poda”, foot. Hence, you will note the lobster has jointed appendages…and since lobsters are also decapods (“deca” being Greek for ten) it has ten legs (five pairs). As invertebrate crustaceans, lobsters also have a hard outer shell or exoskeleton, and no inner skeleton or bones.
Who can fish for lobster?
You need a license to fish for lobster, whether you are a multi-generational resident, or a weekend tourist. The rules and regulations vary by state and province. The Maine Department of Marine Resources provides a good example, and more information can be found in their ‘Guide to Lobstering in Maine’.
Where are lobsters caught?
Their historic natural habitat extends as far south as North Carolina, but commercial lobster fishing is primarily found from Rhode Island north to Newfoundland.
How do you catch a lobster?
Lobsters are fished with baited traps, also known as pots. A harvester will put a bag full of bait (historically herring or other fish) in each trap that is dropped from the boat, or “set”. The trap is attached by a rope (trap line) to a floating buoy to mark its location. Buoys are painted with particular colors that are registered by each harvester, which helps identify to whom each trap belongs.
Each trap is allowed to “soak”, or stay in the water for a few days before the boat returns to haul up each trap. The captain will pull the boat up beside the trap and snag the buoy with a gaffe, a special hook designed for that purpose. The trap line will then be brought onto the boat and connected to a hydraulic trap hauler, an automated pulley-like system that reels the trap up from the bottom to the side of the boat. Once on the boat, the crew will remove the lobsters from the trap. Those of legal size will be kept and those that are too small or too big, and those that are v-notched (to identify a reproductive female lobster), will be returned to the water. A new bait bag is put in the trap and it is the re-set for the next haul
Lobster boats, as the name implies, are particularly suited to the needs of the lobstermen. However, they have been used for other purposes, including as pleasure craft; research vessels; and for other fisheries.
There are some variations in the types of lobster boats typically used in the lobster fishery. They can have outboard motors, inboard gasoline motors, or inboard diesel motors. Shorter, smaller boats (14-22 feet) are used by those who fish a smaller number of traps (typically young people getting started or recreational license holders). Longer, larger boats from 22-45 feet are used by most inshore lobstermen who make their living harvesting lobsters. Even larger boats are used in the offshore fishery, where lobstermen will go out to sea for several days at a time.
Standard characteristics of a working inshore lobsterboat include a single engine; a low trunk cabin; a standing shelter, usually close to midship, with an open cockpit aft (behind it); and sloping rails (downward from bow to stern) to allow for a shorter distance from water to rail (freeboard) in the back half of the boat for easier hauling of traps.
Most modern lobsterboats are made of figerglass and are equipped with an hydraulic trap hauler, a marine radio, GPS chartplotter, depth sounder, and radar. An excellent source for more complete information about the design and building of lobsterboats is the book Maine Lobsterboats: Builders and Lobstermen Speak of Their Craft by Virginia Thorndike (1998, Down East Books, ISBN 0-89272-403-X)
Most modern-day lobster traps (also called pots) are rectangular(for easy stacking when out of water), and are constructed of coated wire mesh. Wire traps began to replace traditional wooden traps in the late 1970s. Wire traps require less maintenance and are lighter out of water (about 40 lbs. vs. 125 lbs.) than wet wooden traps – yet heavier in the water (about 35 lbs. vs. 7 lbs.) This makes them easier to maneuver out of water and more stable in the water. The typical trap costs between $150-$200.
Here’s how a lobster trap works:
A lobster will enter through the net “head” to go after the bait in a bait bag placed in the “kitchen.” When it tries to exit it lands in the “bedroom” or “parlor.” Some traps have more than one kitchen and bedroom. Traps are required to have an escape vent that is large enough to let all but the legal-sized lobsters escape. Traps are also equipped with runners that help prevent legs, claws and antennae from being pinched between the bottom of the trap and the boat when the traps are hauled. Most areas also require traps to have a biodegradable “ghost panel.” This panel will eventually degrade and release, allowing a large space for lobsters to escape from “ghost traps” (those that have broken free of their buoy lines and are therefore unretrievable).
Here are “job descriptions” for some of the basic jobs connected to lobstering and the lobster industry:
Lobsterman or Harvester: A lobsterman (and most women prefer to be called lobstermen) is a man or woman who actually holds a commercial license and fishes for (or harvests) lobster. Inshore lobstermen set and haul traps or trawls (two or more traps attached to each other with rope). Lobstermen must be able to safely navigate a boat, moving from buoy to buoy to haul traps. They must be able to lift traps, which can weigh 40 pounds or more. They must also have accounting skills to keep track of expenses and income, and must be able to interpret the federal and state rules and regulations that are part of lobster management directives. Other duties include maintaining their lobster boat, keeping traps in good repair, obtaining bait and stuffing bait bags, and negotiating the sale of their lobsters.
Sternman: Also known as an aftsman or deck-hand, a sternman does not actually hold a lobster license, but assists a lobsterman in the harvesting of lobster. He or she will bait, empty, stack, and drop traps. They do not haul traps or pilot the boat.
Lobster Dealer: The lobster dealer typically runs the wharf in the harbor the lobstermen fish out of, and where they return to sell their catch. They buy lobsters from the harvesters, and sell them to a variety of outlets (i.e. restaurants, processors, and even other dealers). The lobster dealer also generally supplies bait to the lobstermen, and sometimes other marine supplies as well. Sometimes several lobstermen from one area will band together and form a cooperative (co-op) — acting as their own lobster dealer.
Lobster Pound Owner: These people store live lobsters in coves or inlets that have been dammed in order to keep lobsters confined, yet allow for the flow of fresh tidal waters. Such coves or inlets are called tidal lobster pounds. Lobsters are stored in order to provide for the live market when catch rates are seasonally lower.
Lobster Processor: Owners of lobster processing operations buy live lobsters from many dealers and other sources. Workers will then “process” or prepare the lobster for sale in the wholesale or retail marketplace. Processed lobster can take a variety of forms. Most is cooked and removed from the shell, and then sold as fresh or frozen meat. Sometimes the lobster is cooked and frozen whole in the shell. Other times the lobster is frozen uncooked, either whole or tails only. Lobster can also be canned or used as an ingredient in a number of value-added products.
Lobster Scientist: Scientists from a number of different fields of study (for example biology, microbiology, animal & veterinary science, food science, etc.) may specialize in lobster research. Lobster Scientists can conduct research at universities, for the goverment in lobster management, or in private laboratories. Their work is focused on keeping the lobster resource healthy and the fishery successful.