Common Periwinkle
Encyclopedia
The common periwinkle or winkle, scientific name Littorina littorea, is a species
of small edible sea snail
, a marine
gastropod mollusk which has gill
s and an operculum
, and is classified within the family Littorinidae
, the periwinkles.
This is a robust intertidal species with a dark and sometimes banded shell. It lives on the rocky shores of the North Atlantic Ocean
.
The shell
is broadly ovate, thick, sharply pointed except when eroded. The shell contains 6 to 7 whorls with some fine threads and wrinkles. The color is variable from grayish to gray-brown, often with dark spiral bands.The base of the columella
is white. The shell lacks an umbilicus. The white outer lip is sometimes checkered with brown patches. The inside of the shell has a chocolate-brown color.
The width of the shell ranges from 10 to 12 mm at maturity. with an average size of 16-38 mm.
Shell height can reach up to 30 mm, 43 mm or 52 mm.
As a result of its robust nature, Littorina littorea can be highly variable in phenotype with several different morphs present. It is thought that its phenotypic variations are indicative of a speciation event, as opposed to phenotypic plasticity. This is of particular importance to evolutionary biology as it presents the possible opportunity to view a transitional phase in the evolutionary life of an organism.
, along the coasts of northern Spain
, Scotland
, Ireland
, Scandinavia
and Russia
.
, possibly by rock ballast in the mid-19th century. The first recorded case was in 1840 in the Gulf of St. Lawrence. It is now a predominant mollusc from New Jersey
northward to Newfoundland. It was accidentally introduced to the North American East Coast within the last few centuries and it is now extraordinarily abundant on New England
rocky shores. In Canada, their range includes New Brunswick
, Nova Scotia
, Quebec
, Newfoundland and Labrador
.
This species is also found on the West Coast of the United States
, from Washington (U.S. state) to California.
Littorina littorea is now the most common marine snail along the North Atlantic coast. It has been shown to fundamentally change North Atlantic intertidal ecosystems via grazing activities, altering the distribution and abundance of algae on rocky shores and converting soft-sediment habitats to hard substrates, as well as competitively displacing some native species. The presence of this species has caused extensive damage due to interspecific competition
with native intertidal gastropods.
The common periwinkle is mainly found on rocky shore
s in the higher and middle intertidal zone
. It sometimes lives in small tide pool
s. It may also be found in mud
dy habitat
s such as estuaries, and can reach depths of 180 ft.
grazer, but will feed on small invertebrate
s such as barnacle
larvae. They use their radula
to scrape algae from rocks, and, in the salt marsh
community, pick up algae from the cord grass, or from the biofilm
that covers the surface of mud in estuaries or bay
s.
contained in a corneous
capsule from which larva
e escape and settle to the bottom. This species can breed year round depending on the local climate. It reaches maturity at 10 mm, and lives 5 to 10 years.
s throughout Europe
, and is therefore known to have been an important source of food since at least 7500 BC in Scotland. It is still collected in huge quantities in Scotland, mostly for export to the Continent, and also consumed locally. The official landings figures for Scotland indicate that over 2,000 tonnes of winkles are exported annually. This makes winkles the sixth most important shellfish harvested in Scotland in terms of tonnage, and seventh most important in terms of value. However, since actual harvests are probably twice reported levels, the species may actually be the fourth and sixth most important, respectively.
They are usually picked off the rocks by hand or caught in a drag
from a boat. They are eaten in Great Britain
and Ireland
where they are commonly referred to as winkles or in some areas willicks or wilks, and in Belgium
where they are called crickles. They are commonly sold in paper bag
s near beaches in Ireland, salted and with a pin
attached to the bag to enable the extraction of the soft parts from the shell
.
Periwinkles are considered a delicacy
in African and Asian cuisine
. The meat is high in protein
and low in fat
; according to the USDA National Nutrient Database for Standard Reference
, raw snails in general are about 80% water, 15% protein, and 1.4% fat.
Periwinkles are also used as bait for catching small fish
. The shell is usually crushed and the soft parts extracted and put on a hook.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of small edible sea snail
Sea snail
Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....
, a marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
gastropod mollusk which has gill
Gill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
s and an operculum
Operculum (gastropod)
The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...
, and is classified within the family Littorinidae
Littorinidae
Littorinidae is a taxonomic family of over 200 species of sea snails, marine gastropod molluscs in the clade Littorinimorpha, commonly known as periwinkles and found world-wide.-Names:...
, the periwinkles.
This is a robust intertidal species with a dark and sometimes banded shell. It lives on the rocky shores of the North Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
.
Description
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...
is broadly ovate, thick, sharply pointed except when eroded. The shell contains 6 to 7 whorls with some fine threads and wrinkles. The color is variable from grayish to gray-brown, often with dark spiral bands.The base of the columella
Columella
Lucius Junius Moderatus Columella is the most important writer on agriculture of the Roman empire. Little is known of his life. He was probably born in Gades , possibly of Roman parents. After a career in the army , he took up farming...
is white. The shell lacks an umbilicus. The white outer lip is sometimes checkered with brown patches. The inside of the shell has a chocolate-brown color.
The width of the shell ranges from 10 to 12 mm at maturity. with an average size of 16-38 mm.
Shell height can reach up to 30 mm, 43 mm or 52 mm.
As a result of its robust nature, Littorina littorea can be highly variable in phenotype with several different morphs present. It is thought that its phenotypic variations are indicative of a speciation event, as opposed to phenotypic plasticity. This is of particular importance to evolutionary biology as it presents the possible opportunity to view a transitional phase in the evolutionary life of an organism.
Distribution
Common periwinkles are native to the northeastern Atlantic OceanAtlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
, along the coasts of northern Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
, Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
, Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
, Scandinavia
Scandinavia
Scandinavia 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 Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
.
Introductions to North America
Common periwinkles have been introduced to the Atlantic coast of North AmericaNorth America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, possibly by rock ballast in the mid-19th century. The first recorded case was in 1840 in the Gulf of St. Lawrence. It is now a predominant mollusc from New Jersey
New Jersey
New 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...
northward to Newfoundland. It was accidentally introduced to the North American East Coast within the last few centuries and it is now extraordinarily abundant on New England
New England
New England is a region in the northeastern corner of the United States consisting of the six states of Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, and Connecticut...
rocky shores. In Canada, their range includes New Brunswick
New Brunswick
New Brunswick is one of Canada's three Maritime provinces and is the only province in the federation that is constitutionally bilingual . The provincial capital is Fredericton and Saint John is the most populous city. Greater Moncton is the largest Census Metropolitan Area...
, Nova Scotia
Nova Scotia
Nova Scotia is one of Canada's three Maritime provinces and is the most populous province in Atlantic Canada. The name of the province is Latin for "New Scotland," but "Nova Scotia" is the recognized, English-language name of the province. The provincial capital is Halifax. Nova Scotia is the...
, Quebec
Quebec
Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....
, Newfoundland and Labrador
Labrador
Labrador is the distinct, northerly region of the Canadian province of Newfoundland and Labrador. It comprises the mainland portion of the province, separated from the island of Newfoundland by the Strait of Belle Isle...
.
This species is also found on the 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...
, from Washington (U.S. state) to California.
Littorina littorea is now the most common marine snail along the North Atlantic coast. It has been shown to fundamentally change North Atlantic intertidal ecosystems via grazing activities, altering the distribution and abundance of algae on rocky shores and converting soft-sediment habitats to hard substrates, as well as competitively displacing some native species. The presence of this species has caused extensive damage due to interspecific competition
Interspecific competition
Interspecific competition, in ecology, is a form of competition in which individuals of different species compete for the same resource in an ecosystem...
with native intertidal gastropods.
Habitat
Rocky shore
A rocky shore is an intertidal area of seacoasts where solid rock predominates. Rocky shores are biologically rich environments, and make the ideal natural laboratory for studying intertidal ecology and other biological processes...
s in the higher and middle intertidal zone
Intertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...
. It sometimes lives in small tide pool
Tide pool
Tide pools are rocky pools by oceans that are filled with seawater. Many of these pools exist as separate entities only at low tide.Tide pools are habitats of uniquely adaptable animals that have engaged the special attention of naturalists and marine biologists, as well as philosophical...
s. It may also be found in mud
Mud
Mud is a mixture of water and some combination of soil, silt, and clay. Ancient mud deposits harden over geological time to form sedimentary rock such as shale or mudstone . When geological deposits of mud are formed in estuaries the resultant layers are termed bay muds...
dy habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s such as estuaries, and can reach depths of 180 ft.
Feeding
Littorina littorea is an omnivorous, grazing intertidal gastropod. The common periwinkle is primarily an algaeAlgae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
grazer, but will feed on small invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s such as barnacle
Barnacle
A barnacle is a type of arthropod belonging to infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. They are sessile suspension feeders, and have...
larvae. They use their 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...
to scrape algae from rocks, and, in the salt marsh
Salt marsh
A salt marsh is an environment in the upper coastal intertidal zone between land and salt water or brackish water, it is dominated by dense stands of halophytic plants such as herbs, grasses, or low shrubs. These plants are terrestrial in origin and are essential to the stability of the salt marsh...
community, pick up algae from the cord grass, or from the biofilm
Biofilm
A biofilm is an aggregate of microorganisms in which cells adhere to each other on a surface. These adherent cells are frequently embedded within a self-produced matrix of extracellular polymeric substance...
that covers the surface of mud in estuaries or bay
Bay
A bay is an area of water mostly surrounded by land. Bays generally have calmer waters than the surrounding sea, due to the surrounding land blocking some waves and often reducing winds. Bays also exist as an inlet in a lake or pond. A large bay may be called a gulf, a sea, a sound, or a bight...
s.
Life cycle
Littorina littorea is oviparous, reproducing annually with internal fertilization of egg capsules that are then shed directly into the sea, leading to a planktotrophic larval development time of four to seven weeks. Females lay 10,000 to 100,000 eggsEgg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
contained in a corneous
Corneous
Corneous is a biological and medical term meaning horny, in other words made out of a substance similar to that of horns and hooves in some mammals....
capsule from which larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e escape and settle to the bottom. This species can breed year round depending on the local climate. It reaches maturity at 10 mm, and lives 5 to 10 years.
Human use
This species appears in prehistoric shellfish middenMidden
A midden, is an old dump for domestic waste which may consist of animal bone, human excrement, botanical material, vermin, shells, sherds, lithics , and other artifacts and ecofacts associated with past human occupation...
s throughout 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...
, and is therefore known to have been an important source of food since at least 7500 BC in Scotland. It is still collected in huge quantities in Scotland, mostly for export to the Continent, and also consumed locally. The official landings figures for Scotland indicate that over 2,000 tonnes of winkles are exported annually. This makes winkles the sixth most important shellfish harvested in Scotland in terms of tonnage, and seventh most important in terms of value. However, since actual harvests are probably twice reported levels, the species may actually be the fourth and sixth most important, respectively.
They are usually picked off the rocks by hand or caught in a drag
Drag
- In science and technology :* Drag , the force which resists motion of an object through a fluid* Drag equation, a mathematical equation used in analyzing the magnitude of drag caused by fluid flow...
from a boat. They are eaten in Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
and Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
where they are commonly referred to as winkles or in some areas willicks or wilks, and in Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
where they are called crickles. They are commonly sold in paper bag
Paper bag
A paper bag or paper sack is a preformed container made of paper, usually with an opening on one side. It can be one layer of paper or multiple layers of paper and other flexible materials. A bag is used for packaging and/or carrying items....
s near beaches in Ireland, salted and with a pin
Pin
A pin is a device used for fastening objects or material together.Pin may also refer to:* Award pin, a small piece of metal or plastic with a pin attached given as an award for some achievement...
attached to the bag to enable the extraction of the soft parts from the shell
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...
.
Periwinkles are considered a delicacy
Delicacy
A delicacy is a food item that is considered highly desirable in certain cultures. Often this is because of unusual flavors or characteristics or because it is rare....
in African and Asian cuisine
Asian cuisine
Asian cuisine styles can be broken down into several tiny regional styles that have roots in the peoples and cultures of those regions. The major types can be roughly defined as East Asian with its origins in Imperial China and now encompassing modern Japan and the Korean peninsula; Southeast Asian...
. The meat is high in protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
and low in fat
Fat
Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...
; according to the USDA National Nutrient Database for Standard Reference
United States National Agricultural Library
The United States National Agricultural Library is one of the world's largest agricultural research libraries, and serves as a National Library of the United States and as the library of the United States Department of Agriculture...
, raw snails in general are about 80% water, 15% protein, and 1.4% fat.
Periwinkles are also used as bait for catching small fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
. The shell is usually crushed and the soft parts extracted and put on a hook.
Further reading
- Abbott R. T. (1974). American Seashells. Second edition. Van Nostrand Rheinhold, New York
- Abbott R. T. (1986). Seashells of North America, St. Martin's Press, New York
External links
- Littorina littorea (mollusc) from the Invasive Species Specialist Group website of the World Conservation UnionWorld Conservation UnionThe International Union for Conservation of Nature and Natural Resources is an international organization dedicated to finding "pragmatic solutions to our most pressing environment and development challenges." The organization publishes the IUCN Red List, compiling information from a network of...
- Common periwinkle from the Marine Life Information Network for Britain and Ireland
- Anatomy of the Periwinkle from a Lander UniversityLander UniversityLander University is a public university located in Greenwood, South Carolina. It is the state's smallest publicly-funded baccalaureate institution.-History:...
website