Great Grey Slug
Encyclopedia
Limax maximus also known by common names such as the great grey slug, or the leopard slug, is one of the largest kinds of keeled air-breathing land slug
in the world, (Limax cinereoniger
being the largest). It is in the family Limacidae
, the keeled slugs.
Limax maximus is the type species
of the genus Limax. The adult slug measures 10-20 cm
(4-8 in
) in length and is generally a light greyish or grey-brown with darker spots and blotches, although the coloration and exact patterning of the body of this slug species is quite variable.
This species has a very unusual and distinctive mating method, where the pair of slugs use a thick thread of mucus to hang suspended in the air from a tree branch or other structure.
Although native to Europe
, this species has been accidentally introduced to many other parts of the world.
(4-8 in
).
The greater part of the body is rounded, but there is a short keel
on its tail, with about 48 longitudinal rows of elongate, detached tubercles.
The animal's body color is pale-grey, ash-colored, brownish or sometimes yellowish-white. The body is longitudinally streaked or spotted with black. The shield is always black-spotted. The sole of the foot is ash or yellowish-ash colored, and the color is always uniform. The foot-fringe is pale, with a row of minute submarginal blackish tubercles.
Every Limax maximus differs slightly in its pattern of black spots:
The tentacle
s are very long and slender. The reproductive pore is near the base of the right upper tentacle.
The shield is oblong, about one-third of the total length of the animal. The shield is rounded in front, angular behind, and forming an angle
of about 80 degrees when in motion, usually of a similar tint to the body, but boldly marbled or maculate with black, somewhat concentrically and interruptedly ridged around a sub-posterior nucleus.
The pneumostome
is just posterior to the mid-point of the mantle, as it is in all Limacidae.
The mucus
is colorless and iridescent, and not very adhesive.
Although color varieties have no actual taxonomic significance, a large number of color varieties have been described, prominent among them being the varieties serpentinus, vulgaris, cellarius (typical), johnstoni, maculatus, ferrussaci, obscurus, fasciatus and rufescens, of Alfred Moquin-Tandon
, and cornaliee, of Pini
.
As well as different tints and markings, various shades of color exist in Limax maximus:
The shell
of Limax maximus is reduced and internal, under the shield. The occurrence of this internal shell was known to Pliny the Elder
; the shell was used by the ancient physicians for the sake of its carbonate
of lime.
The calcitic shell is situated beneath the hinder part of the shield, and is perceptible through the skin. The color of the shell is whitish. The shape of the shell is oblong-oval and thin, slightly convex above, and correspondingly concave beneath, with a membranous margin. The apex
or nucleus is at the posterior margin but inclined towards the left side, and forming the apophysis by which the shell is organically attached to the animal. The length of the shell is 13 mm (1/2 inch) and the width of the shell is 7 mm (1/4 inch). Shells of different Limacidae species are undiagnostic: in other words, they are not helpful for identification purpose.
Digestive system
: The formula of the radula
is: 62-73/ × 138-157. The intestine
has six convolutions and is without a caecum. Of the six convolutions of the intestine, four are imbedded in the liver, and two hang freely in the body cavity.
The nervous system
is composed of the typical ganglia. The pedal ganglia are placed beneath the radula sac and joined together by an anterior and a posterior commissure
. The abdominal ganglion lies a little to the right of the median line. The visceral ganglia occupy the angle between the lingual sheath and the oesophagus and the buccal ganglia are widely separated but joined together by a commissure nearly as thick as the ganglia themselves.
Reproductive system
: The hermaphrodite gland (HG) is elongated and large, and is connected with spermoviduct (SD) by means of the hermaphrodite duct (HD) which takes its course through a portion of the albumen gland (AG). The spermoviduct is thick and well convoluted, and separates further down into a vas deferens or sperm-duct (VD) and an oviduct (OV). The former opens into the upper end of a very long penis (P), to which a strong retractor muscle (PRM) is attached. The lower portion of the penis unites with that of the oviduct at the genital orifice, so that there is no vestibule. The receptaculum seminis (RS) opens into the lower end of the penis near the junction of the two ducts.
and Quaternary
deposits.
.
The indigenous distribution of Limax maximus is western and southern Europe and part of western Africa also, maybe originally Mediterranean.
Within Europe, this species is known to occur in a number of different countries and islands including:
Central Europe:
Northern Europe - Scandinavia
Eastern Europe:
This slug species has been introduced to North America. It occurs along the East
and the West Coast
s of that continent.
Its introduction into the United States was first announced by George Washington Tryon
in 1867, when it was discovered in cellars in Philadelphia. Within a few years its presence was noticed at Newport, Rhode Island
, Brooklyn
, Pittsburgh, etc., and it has now become rather numerous in some localities.
East Coast of the United States
:
South Central United States
:
Midwest United States:
West Coast of the United States
:
Other non-indigenous distribution areas include Madeira
, southern Africa, Australia, Tasmania, New Zealand and southern Brazil.
It is inactive in its habits, not very prolific, and exudes a thick and glutinous slime which is iridescent when dried. When alarmed, or at rest, this slug merely draws its head within the shield, but does not otherwise contract its body. When irritated, it is said to expand its shield.
The homing
faculty is strongly developed in this species, which, after its nocturnal rambles or foraging expeditions, usually returns to the particular crevice or chink in which it has established itself.
Limax maximus is capable of associative learning, specifically classical conditioning
, because it is capable of aversion learning
and other types of learning. They can also detect that there are deficiencies in a nutritionally incomplete diet, if the essential amino acid
methionine
is experimentally removed from their food.
s or in other damp areas.
This species is not gregarious. It frequents gardens, damp and shady hedgerows and woods, hiding during the day beneath stones, under fallen trees, or other obscure and damp places. It does however exhibit a decided preference for the vicinity of human habitations, and readily takes up its abode in damp cellars or outbuildings.
In Ireland, this predilection for human dwellings is not exhibited, and the species is restricted to woods and other similar places. It may even be met with almost within high-water mark on the seashore.
for it cleans up dead plants and fungi, and as a carnivore for it hunts down other slugs with its top speed of 6 in/min. However it is also eats young crops faster than they can grow and so is listed as a major agricultural pest by State Departments of Agriculture from Florida to Oregon.
The eggs of this slug are deposited in a cluster, slightly attached to each other. Eggs are transparent, elastic and slightly yellowish in color. The size of the egg is 6×4.5 mm. They hatch in about a month.
The tiny slugs which emerge from the eggs need at least two years to reach sexual maturity.
The lifespan of Limax maximus is 2.5–3 years.
habits of Limax maximus are considered unusual among slugs: the hermaphrodite
slugs court, usually for hours, by circling and licking each other. After this, the slugs will climb into a tree or other high area and then, entwined together, lower themselves on a thick string of mucus
, evert their white translucent mating organs (penis
es) from their gonopore
s (openings on the right side of the head), entwine these organs, and exchange sperm
. Both participants will later lay hundreds of eggs.
A commonly seen practice among many slugs is apophallation
, when one or both of the slugs chews off the other's penis. The penis of these species is curled like a corkscrew
and often becomes entangled in their mate's genitalia in the process of exchanging sperm
. When all else fails, apophallation allows the slugs to separate themselves. Once its penis has been removed, a slug is still able to participate in mating subsequently, but only using the female parts of its reproductive system.
This slug is often infested (as are some other slug species) by a white parasitic slug mite
Riccardoella limacum. These mites can be seen swarming about its body, and live in its respiratory cavity.
-causing nematode
, Angiostrongylus cantonensis, which normally infests the lungs of rat
s, has a larval stage which can only live in mollusks, including slugs.
Previously, this nematode was only known to be a problem in tropical areas, but it has since spread to other regions. Live slugs that are accidentally eaten with improperly cleaned vegetables (such as lettuce
), or improperly cooked slugs (for use in recipes requiring larger slugs such as banana slug
s), can act as a vector for a parasitic infection.
Slug
Slug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...
in the world, (Limax cinereoniger
Limax cinereoniger
Limax cinereoniger is a species of air-breathing land slug, a terrestrial pulmonate gastropod mollusk in the family Limacidae, the keelback slugs.-Description:Rarely this slug can grow up to 30 cm long...
being the largest). It is in the family Limacidae
Limacidae
Limacidae, common name the keelback slugs, are a taxonomic family of medium-sized to very large, air-breathing land slugs, terrestrial pulmonate gastropod molluscs in the superfamily Limacoidea.- Distribution :...
, the keeled slugs.
Limax maximus is the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
of the genus Limax. The adult slug measures 10-20 cm
Centimetre
A centimetre is a unit of length in the metric system, equal to one hundredth of a metre, which is the SI base unit of length. Centi is the SI prefix for a factor of . Hence a centimetre can be written as or — meaning or respectively...
(4-8 in
Inch
An inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot...
) in length and is generally a light greyish or grey-brown with darker spots and blotches, although the coloration and exact patterning of the body of this slug species is quite variable.
This species has a very unusual and distinctive mating method, where the pair of slugs use a thick thread of mucus to hang suspended in the air from a tree branch or other structure.
Although native to Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, this species has been accidentally introduced to many other parts of the world.
External anatomy
The body length of adults of this slug species is 10-20 cmCentimetre
A centimetre is a unit of length in the metric system, equal to one hundredth of a metre, which is the SI base unit of length. Centi is the SI prefix for a factor of . Hence a centimetre can be written as or — meaning or respectively...
(4-8 in
Inch
An inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot...
).
The greater part of the body is rounded, but there is a short keel
Keel (disambiguation)
Keel may be:* Keel, the central beam of the hull of a boatThis meaning has given rise to many other related uses of the word in biology and natural history, including:...
on its tail, with about 48 longitudinal rows of elongate, detached tubercles.
The animal's body color is pale-grey, ash-colored, brownish or sometimes yellowish-white. The body is longitudinally streaked or spotted with black. The shield is always black-spotted. The sole of the foot is ash or yellowish-ash colored, and the color is always uniform. The foot-fringe is pale, with a row of minute submarginal blackish tubercles.
Every Limax maximus differs slightly in its pattern of black spots:
Tentacle
A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...
s are very long and slender. The reproductive pore is near the base of the right upper tentacle.
The shield is oblong, about one-third of the total length of the animal. The shield is rounded in front, angular behind, and forming an angle
of about 80 degrees when in motion, usually of a similar tint to the body, but boldly marbled or maculate with black, somewhat concentrically and interruptedly ridged around a sub-posterior nucleus.
The pneumostome
Pneumostome
The pneumostome is a feature of the external body anatomy of an air-breathing land slug or land snail. It is a part of the respiratory system of gastropods....
is just posterior to the mid-point of the mantle, as it is in all Limacidae.
The mucus
Mucus
In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes. Mucous fluid is typically produced from mucous cells found in mucous glands. Mucous cells secrete products that are rich in glycoproteins and water. Mucous fluid may also originate from mixed glands, which...
is colorless and iridescent, and not very adhesive.
Although color varieties have no actual taxonomic significance, a large number of color varieties have been described, prominent among them being the varieties serpentinus, vulgaris, cellarius (typical), johnstoni, maculatus, ferrussaci, obscurus, fasciatus and rufescens, of Alfred Moquin-Tandon
Alfred Moquin-Tandon
Christian Horace Benedict Alfred Moquin-Tandon was a French naturalist and doctor.Moquin-Tandon was professor of zoology at Marseille from 1829 until 1833, when he was appointed professor of botany and director of the botanical gardens at Toulouse. In 1850, he was sent by the French government to...
, and cornaliee, of Pini
Pini
Pini is a surname, and may refer to:*Antonio Pini-Corsi*Carolina Pini*Rodolfo Pini*Ryan Pini*Karla Pini*Wendy and Richard Pini, creators of the Elfquest seriesPini may also refer to:...
.
As well as different tints and markings, various shades of color exist in Limax maximus:
Internal anatomy
Gastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
of Limax maximus is reduced and internal, under the shield. The occurrence of this internal shell was known to Pliny the Elder
Pliny the Elder
Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...
; the shell was used by the ancient physicians for the sake of its carbonate
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....
of lime.
Apex (mollusc)
Apex is an anatomical term for the tip of the mollusc shell of a gastropod, scaphopod, or cephalopod mollusc.-Gastropods:The word "apex" is most often used to mean the tip of the spire of the shell of a gastropod...
or nucleus is at the posterior margin but inclined towards the left side, and forming the apophysis by which the shell is organically attached to the animal. The length of the shell is 13 mm (1/2 inch) and the width of the shell is 7 mm (1/4 inch). Shells of different Limacidae species are undiagnostic: in other words, they are not helpful for identification purpose.
Digestive system
Digestive system of gastropods
The digestive system of gastropods has evolved to suit almost every kind of diet and feeding behavior. Gastropods as the largest taxonomic class of the mollusca are very diverse indeed: the group includes carnivores, herbivores, scavengers, filter feeders, and even parasites.In particular, the...
: The formula of the radula
Radula
The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared rather inaccurately to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus...
is: 62-73/ × 138-157. The intestine
Intestine
In human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...
has six convolutions and is without a caecum. Of the six convolutions of the intestine, four are imbedded in the liver, and two hang freely in the body cavity.
The nervous system
Nervous system of gastropods
The nervous system of gastropods consists of a series of paired ganglia connected by major nerve cords, and a number of smaller branching peripheral nerves.The brain of a gastropod consists of three pairs of ganglia, all located close to the oesophagus...
is composed of the typical ganglia. The pedal ganglia are placed beneath the radula sac and joined together by an anterior and a posterior commissure
Commissure
A commissure is the place where two things are joined. The term is used especially in the fields of anatomy and biology.In anatomy, commissure refers to a bundle of nerve fibers that cross the midline at their level of origin or entry .* The most common usage of the term refers to the brain's...
. The abdominal ganglion lies a little to the right of the median line. The visceral ganglia occupy the angle between the lingual sheath and the oesophagus and the buccal ganglia are widely separated but joined together by a commissure nearly as thick as the ganglia themselves.
Reproductive system
Reproductive system of gastropods
The reproductive system of gastropods varies greatly from one group to another within this very large and diverse taxonomic class of animals...
: The hermaphrodite gland (HG) is elongated and large, and is connected with spermoviduct (SD) by means of the hermaphrodite duct (HD) which takes its course through a portion of the albumen gland (AG). The spermoviduct is thick and well convoluted, and separates further down into a vas deferens or sperm-duct (VD) and an oviduct (OV). The former opens into the upper end of a very long penis (P), to which a strong retractor muscle (PRM) is attached. The lower portion of the penis unites with that of the oviduct at the genital orifice, so that there is no vestibule. The receptaculum seminis (RS) opens into the lower end of the penis near the junction of the two ducts.
Fossil distribution
The internal shells of the different species of Limacidae are not recognizable to the species level. Therefore, the fossil distribution of Limax maximus (and other Limacidae species) is unknown. Unidentified calcitic shells of Limacidae are known from European TertiaryTertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
and Quaternary
Quaternary
The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present...
deposits.
Indigenous distribution
This species is widely distributed but it is generally considered to be native to EuropeEurope
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
.
The indigenous distribution of Limax maximus is western and southern Europe and part of western Africa also, maybe originally Mediterranean.
Within Europe, this species is known to occur in a number of different countries and islands including:
- Great Britain - Limax maximus was described from a scientific point from England in Animalium Angliae Tres Tractatus … Alter de Cochleis tum Terrestribus tum Fluviatilibus by Dr. Martin ListerMartin ListerMartin Lister FRS was an English naturalist and physician.-Life:Lister was born at Radcliffe, near Buckingham, the son of Sir Martin Lister MP for Brackley in the Long Parliament and his wife Susan Temple daughter of Sir Alexander Temple. Lister was connected to a number of well known individuals...
among first three British slugs in 1678. However the existence of Limax maximus in England was indicated twelve years before in Christopher Merret's Pinax Rerum Naturalium Britannicarum in 1667. - Ireland
- BeneluxBeneluxThe Benelux is an economic union in Western Europe comprising three neighbouring countries, Belgium, the Netherlands, and Luxembourg. These countries are located in northwestern Europe between France and Germany...
: Belgium, Netherlands, Luxembourg - France
- Switzerland
- Bulgaria
- ScandinaviaScandinaviaScandinavia is a cultural, historical and ethno-linguistic region in northern Europe that includes the three kingdoms of Denmark, Norway and Sweden, characterized by their common ethno-cultural heritage and language. Modern Norway and Sweden proper are situated on the Scandinavian Peninsula,...
- and other areas
Nonindigenous distribution
The non-indigenous distribution of Limax maximus includes:Central Europe:
- Czech Republic
- Poland
- Slovakia
- Hungary
- Germany
- Austria
Northern Europe - Scandinavia
- Norway
- Sweden - The type locality of Limax maximus is probably Sweden.
Eastern Europe:
- Latvia
- Lithuania - vulnerable
- Belarus
- Ukraine
This slug species has been introduced to North America. It occurs along the East
East Coast of the United States
The East Coast of the United States, also known as the Eastern Seaboard, refers to the easternmost coastal states in the United States, which touch the Atlantic Ocean and stretch up to Canada. The term includes the U.S...
and the West Coast
West Coast of the United States
West Coast or Pacific Coast are terms for the westernmost coastal states of the United States. The term most often refers to the states of California, Oregon, and Washington. Although not part of the contiguous United States, Alaska and Hawaii do border the Pacific Ocean but can't be included in...
s of that continent.
Its introduction into the United States was first announced by George Washington Tryon
George Washington Tryon
George Washington Tryon, Jr. was an American malacologist who worked at the Academy of Natural Sciences in Philadelphia.- Biography :George Washington Tryon was the son of Edward K. Tryon and Adeline Savidt...
in 1867, when it was discovered in cellars in Philadelphia. Within a few years its presence was noticed at Newport, Rhode Island
Newport, Rhode Island
Newport is a city on Aquidneck Island in Newport County, Rhode Island, United States, about south of Providence. Known as a New England summer resort and for the famous Newport Mansions, it is the home of Salve Regina University and Naval Station Newport which houses the United States Naval War...
, Brooklyn
Brooklyn
Brooklyn is the most populous of New York City's five boroughs, with nearly 2.6 million residents, and the second-largest in area. Since 1896, Brooklyn has had the same boundaries as Kings County, which is now the most populous county in New York State and the second-most densely populated...
, Pittsburgh, etc., and it has now become rather numerous in some localities.
East Coast of the United States
East Coast of the United States
The East Coast of the United States, also known as the Eastern Seaboard, refers to the easternmost coastal states in the United States, which touch the Atlantic Ocean and stretch up to Canada. The term includes the U.S...
:
- MaineMaineMaine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...
- MarylandMarylandMaryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...
- MassachusettsMassachusettsThe Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...
- New HampshireNew HampshireNew Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian...
- New JerseyNew JerseyNew Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
- New YorkNew YorkNew York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
- North CarolinaNorth CarolinaNorth Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
- OhioOhioOhio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...
- West VirginiaWest VirginiaWest Virginia is a state in the Appalachian and Southeastern regions of the United States, bordered by Virginia to the southeast, Kentucky to the southwest, Ohio to the northwest, Pennsylvania to the northeast and Maryland to the east...
- PennsylvaniaPennsylvaniaThe Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...
- Rhode IslandRhode IslandThe state of Rhode Island and Providence Plantations, more commonly referred to as Rhode Island , is a state in the New England region of the United States. It is the smallest U.S. state by area...
- South CarolinaSouth CarolinaSouth Carolina is a state in the Deep South of the United States that borders Georgia to the south, North Carolina to the north, and the Atlantic Ocean to the east. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence...
- VirginiaVirginiaThe Commonwealth of Virginia , is a U.S. state on the Atlantic Coast of the Southern United States. Virginia is nicknamed the "Old Dominion" and sometimes the "Mother of Presidents" after the eight U.S. presidents born there...
South Central United States
South Central United States
The South Central United States or South Central states is a region of the United States located in the south central part of the country. It evolved out of the archaic southwest, which originally was literally the western U.S. South...
:
- ArkansasArkansasArkansas is a state located in the southern region of the United States. Its name is an Algonquian name of the Quapaw Indians. Arkansas shares borders with six states , and its eastern border is largely defined by the Mississippi River...
- OklahomaOklahomaOklahoma is a state located in the South Central region of the United States of America. With an estimated 3,751,351 residents as of the 2010 census and a land area of 68,667 square miles , Oklahoma is the 28th most populous and 20th-largest state...
- TennesseeTennesseeTennessee is a U.S. state located in the Southeastern United States. It has a population of 6,346,105, making it the nation's 17th-largest state by population, and covers , making it the 36th-largest by total land area...
Midwest United States:
- IllinoisIllinoisIllinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
- IowaIowaIowa is a state located in the Midwestern United States, an area often referred to as the "American Heartland". It derives its name from the Ioway people, one of the many American Indian tribes that occupied the state at the time of European exploration. Iowa was a part of the French colony of New...
- MichiganMichiganMichigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
- MissouriMissouriMissouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...
West Coast of the United States
West Coast of the United States
West Coast or Pacific Coast are terms for the westernmost coastal states of the United States. The term most often refers to the states of California, Oregon, and Washington. Although not part of the contiguous United States, Alaska and Hawaii do border the Pacific Ocean but can't be included in...
:
- CaliforniaCaliforniaCalifornia is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
since 1896 - MontanaMontanaMontana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...
- OregonOregonOregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
- Washington
-
-
-
- found in some parts of Canada
-
-
Other non-indigenous distribution areas include Madeira
Madeira
Madeira is a Portuguese archipelago that lies between and , just under 400 km north of Tenerife, Canary Islands, in the north Atlantic Ocean and an outermost region of the European Union...
, southern Africa, Australia, Tasmania, New Zealand and southern Brazil.
Behavior
Limax maximus is a nocturnal animal which feeds at night.It is inactive in its habits, not very prolific, and exudes a thick and glutinous slime which is iridescent when dried. When alarmed, or at rest, this slug merely draws its head within the shield, but does not otherwise contract its body. When irritated, it is said to expand its shield.
The homing
Homing (biology)
Homing is the inherent ability of an animal to navigate towards an original location through unfamiliar areas. This location may be either a home territory, or a breeding spot.-Uses:...
faculty is strongly developed in this species, which, after its nocturnal rambles or foraging expeditions, usually returns to the particular crevice or chink in which it has established itself.
Limax maximus is capable of associative learning, specifically classical conditioning
Classical conditioning
Classical conditioning is a form of conditioning that was first demonstrated by Ivan Pavlov...
, because it is capable of aversion learning
Taste aversion
Conditioned taste aversion, also known as Garcia effect , and as "Sauce-Bearnaise Syndrome", a term coined by Seligman and Hager, is an example of classical conditioning or Pavlovian conditioning...
and other types of learning. They can also detect that there are deficiencies in a nutritionally incomplete diet, if the essential amino acid
Essential amino acid
An essential amino acid or indispensable amino acid is an amino acid that cannot be synthesized de novo by the organism , and therefore must be supplied in the diet.-Essentiality vs. conditional essentiality in humans:...
methionine
Methionine
Methionine is an α-amino acid with the chemical formula HO2CCHCH2CH2SCH3. This essential amino acid is classified as nonpolar. This amino-acid is coded by the codon AUG, also known as the initiation codon, since it indicates mRNA's coding region where translation into protein...
is experimentally removed from their food.
Habitat
The slugs are almost always found near human habitation — usually in lawns, gardens, cellarBasement
__FORCETOC__A basement is one or more floors of a building that are either completely or partially below the ground floor. Basements are typically used as a utility space for a building where such items as the furnace, water heater, breaker panel or fuse box, car park, and air-conditioning system...
s or in other damp areas.
This species is not gregarious. It frequents gardens, damp and shady hedgerows and woods, hiding during the day beneath stones, under fallen trees, or other obscure and damp places. It does however exhibit a decided preference for the vicinity of human habitations, and readily takes up its abode in damp cellars or outbuildings.
In Ireland, this predilection for human dwellings is not exhibited, and the species is restricted to woods and other similar places. It may even be met with almost within high-water mark on the seashore.
Feeding habits
Limax maximus is omnivorous. It is of benefit as a detrivoreDetritivore
Detritivores, also known as detritophages or detritus feeders or detritus eaters or saprophages, are heterotrophs that obtain nutrients by consuming detritus . By doing so, they contribute to decomposition and the nutrient cycles...
for it cleans up dead plants and fungi, and as a carnivore for it hunts down other slugs with its top speed of 6 in/min. However it is also eats young crops faster than they can grow and so is listed as a major agricultural pest by State Departments of Agriculture from Florida to Oregon.
Life cycle
The tiny slugs which emerge from the eggs need at least two years to reach sexual maturity.
The lifespan of Limax maximus is 2.5–3 years.
Mating
The matingMating
In biology, mating is the pairing of opposite-sex or hermaphroditic organisms for copulation. In social animals, it also includes the raising of their offspring. Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization...
habits of Limax maximus are considered unusual among slugs: the hermaphrodite
Hermaphrodite
In biology, a hermaphrodite is an organism that has reproductive organs normally associated with both male and female sexes.Many taxonomic groups of animals do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which both...
slugs court, usually for hours, by circling and licking each other. After this, the slugs will climb into a tree or other high area and then, entwined together, lower themselves on a thick string of mucus
Mucus
In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes. Mucous fluid is typically produced from mucous cells found in mucous glands. Mucous cells secrete products that are rich in glycoproteins and water. Mucous fluid may also originate from mixed glands, which...
, evert their white translucent mating organs (penis
Penis
The penis is a biological feature of male animals including both vertebrates and invertebrates...
es) from their gonopore
Gonopore
A gonopore, sometimes called a gonadopore, is a genital pore in many invertebrates. Hexapods, including insects have a single common gonopore, except mayflies, which have a pair of gonopores...
s (openings on the right side of the head), entwine these organs, and exchange sperm
Sperm
The term sperm is derived from the Greek word sperma and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell...
. Both participants will later lay hundreds of eggs.
A commonly seen practice among many slugs is apophallation
Apophallation
Apophallation is a technique resorted to by some species of air-breathing land slugs such as Limax maximus and Ariolimax spp. In these species of hermaphroditic terrestrial gastropod mollusks, after mating, if the slugs cannot successfully separate, a deliberate amputating of the penis takes...
, when one or both of the slugs chews off the other's penis. The penis of these species is curled like a corkscrew
Corkscrew
A corkscrew is a kitchen tool for drawing stopping corks from wine bottles. Generally, a corkscrew consists of a pointed metallic helix attached to a handle. The user grips the handle and screws the metal point into the cork, until the helix is firmly embedded, then a vertical pull on the...
and often becomes entangled in their mate's genitalia in the process of exchanging sperm
Sperm
The term sperm is derived from the Greek word sperma and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell...
. When all else fails, apophallation allows the slugs to separate themselves. Once its penis has been removed, a slug is still able to participate in mating subsequently, but only using the female parts of its reproductive system.
Parasites
Parasites of Limax maximus include:- The nematodeNematodeThe nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
worm Agfa flexilisAgfa flexilisAgfa flexilis is a species of parasitic nematode....
(Dujardin, 1845) lives in the slug's salivary glands
- The nematode Angiostoma limacisAngiostoma limacisAngiostoma limacis is a species of parasitic nematode....
Dujardin, 1845 lives in the rectum
- Angiostrongylus costaricensisAngiostrongylus costaricensisAngiostrongylus costaricensis is a parasitic nematode.Its distribution include Brazil.- Hosts :* Limax maximus* slugs from the family Veronicellidae...
Morera & Cespedes, 1971
This slug is often infested (as are some other slug species) by a white parasitic slug mite
Slug mite
Riccardoella limacum or the slug mite is a member of the Acari family which is parasitic on slugs and snails. Slug mites are very small , white, and can be seen to move very rapidly over the surface of their host, particularly under the shell rim and near the pulmonary aperture...
Riccardoella limacum. These mites can be seen swarming about its body, and live in its respiratory cavity.
Angiostrongylus cantonensis
A meningitisMeningitis
Meningitis is inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs...
-causing nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
, Angiostrongylus cantonensis, which normally infests the lungs of rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s, has a larval stage which can only live in mollusks, including slugs.
Previously, this nematode was only known to be a problem in tropical areas, but it has since spread to other regions. Live slugs that are accidentally eaten with improperly cleaned vegetables (such as lettuce
Lettuce
Lettuce is a temperate annual or biennial plant of the daisy family Asteraceae. It is most often grown as a leaf vegetable. It is eaten either raw, notably in salads, sandwiches, hamburgers, tacos, and many other dishes, or cooked, as in Chinese cuisine in which the stem becomes just as important...
), or improperly cooked slugs (for use in recipes requiring larger slugs such as banana slug
Banana slug
Banana slug is a common name for three species of air-breathing land slug in the genus Ariolimax. These slugs are often yellow in color and are sometimes spotted with brown like a ripe banana....
s), can act as a vector for a parasitic infection.
Further reading
- Gelperin A. 1974. Olfactory Basis of Homing Behavior in the Giant Garden Slug, Limax maximus. Proc Natl Acad Sci U S A. 1974 March; 71(3): 966–970.
- Wieland S. J. & Gelperin A. 1983. Dopamine elicits feeding motor program in Limax maximus. J Neurosci 1983, 3:1735-1745.