Sea snail
Encyclopedia
Sea snail is a common name
for those snails that normally live in saltwater, marine
gastropod molluscs. (The taxonomic class Gastropoda
also includes snails that live in other habitats, i.e. land snail
s and freshwater snail
s.)
Sea snails are marine gastropods that have shell
s. Those marine gastropods that have no shells, or have only internal shells, are variously known by other common names, including sea slug
, sea hare
, nudibranch
, etc.
Many sea snails are edible and are exploited as food sources by humans. Some well-known kinds of edible sea snails are abalone
, conch
, limpet
s, whelk
s (such as the North American Busycon
species and the North Atlantic Buccinum undatum
) and periwinkles including Littorina littorea.
There is enormous diversity within sea snails; many very different clades of gastropods are either dominated by, or consist exclusively of, sea snails. Because of this great variability, it is not possible to generalize about the feeding, reproduction, habitat and so on of sea snails. Instead it is necessary to look at the articles about individual clades, families, genera or species.
The shells of most species of sea snails are spirally coiled; some however have shells that are conical, and these are often referred to by the common name of limpet
s.
In one unusual family Juliidae
, the shell of the snail has become two hinged plates closely resembling those of a bivalve; this family is sometimes called the "bivalved gastropods".
The shells of living species of sea snails range in size from Syrinx aruanus
, the largest living shelled gastropod species, to minute species whose shells are under 1 mm at adult size.
Because in many cases the shells of sea snails are strong and durable, as a group they are well represented in the fossil record.
or gills, a few species however have a lung, are intertidal, and are active only at low tide when they can move around in the air. These air-breathing species include false limpets in the family Siphonariidae
and another group of false limpets in the family Trimusculidae
.
Many (but not all) sea snails have an operculum
.
, conch
, limpet
s, whelk
s (such as the North American Busycon
species and the North Atlantic Buccinum undatum
) and periwinkles including Littorina littorea.
The shells of sea snails are often found by humans as one kind of seashell
that washes up on beach
es. Because the shells of many sea snails are attractive and durable, they have been used by humans to make necklaces and other jewelry from prehistoric times to the current day.
The shells of a few species of large sea snails within the Vetigastropoda
have a thick layer of nacre
and have been exploited as a source of mother of pearl. Historically the button
industry relied on these species for a number of years.
s. A hermit crab carries the shell by grasping the central columella of the shell using claspers on the tip of its abdomen.
) can be listed as either freshwater snails or marine snails, and some species that live right at, or right above, the high tide level (for example species in the genus Truncatella), are sometimes considered to be sea snails and sometimes listed as land snails.
is an overview of the main clades of living gastropods based on the taxonomy of Bouchet & Rocroi
(2005), with taxa that contain saltwater or brackish water species marked in boldface (some of the highlighted taxa consist entirely of marine species, but some of them also contain freshwater or land species.)
, the main character SpongeBob
has a pet sea snail called Gary
. Gary makes a "meow" vocalization like a cat. The character's eyes are well-developed and colorful, similar to the eyes of species in the sea snail family Strombidae
.
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
for those snails that normally live in saltwater, 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 molluscs. (The taxonomic class Gastropoda
Gastropoda
The Gastropoda or gastropods, more commonly known as snails and slugs, are a large taxonomic class within the phylum Mollusca. The class Gastropoda includes snails and slugs of all kinds and all sizes from microscopic to quite large...
also includes snails that live in other habitats, i.e. land snail
Land snail
A land snail is any of the many species of snail that live on land, as opposed to those that live in salt water and fresh water. Land snails are terrestrial gastropod mollusks that have shells, It is not always an easy matter to say which species are terrestrial, because some are more or less...
s and freshwater snail
Freshwater snail
A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....
s.)
Sea snails are marine gastropods that have 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...
s. Those marine gastropods that have no shells, or have only internal shells, are variously known by other common names, including sea slug
Sea slug
Sea slug is a common name used for several different groups of saltwater snails that either lack a shell or have only an internal shell, in other words this name is used for various lineages of marine gastropod mollusks that are either not conchiferous or appear not to be.The phrase "sea slug" is...
, sea hare
Sea hare
The clade Aplysiomorpha, commonly known as Sea hares or Sea Bags , are medium-sized to very large Opisthobranchia with a soft internal shell made of protein...
, nudibranch
Nudibranch
A nudibranch is a member of what is now a taxonomic clade, and what was previously a suborder, of soft-bodied, marine gastropod mollusks which shed their shell after their larval stage. They are noted for their often extraordinary colors and striking forms...
, etc.
Many sea snails are edible and are exploited as food sources by humans. Some well-known kinds of edible sea snails are abalone
Abalone
Abalone , from aulón, are small to very large-sized edible sea snails, marine gastropod molluscs in the family Haliotidae and the genus Haliotis...
, conch
Conch
A conch is a common name which is applied to a number of different species of medium-sized to large sea snails or their shells, generally those which are large and have a high spire and a siphonal canal....
, limpet
Limpet
Limpet is a common name for a number of different kinds of saltwater and freshwater snails ; it is applied to those snails that have a simple shell which is more or less conical in shape, and either is not spirally coiled, or appears not to be coiled in the adult snails.The name limpet is most...
s, whelk
Whelk
Whelk, also spelled welk or even "wilks", is a common name used to mean one or more kinds of sea snail. The species, genera and families referred to using this common name vary a great deal from one geographic area to another...
s (such as the North American Busycon
Busycon
Busycon is a genus of very large edible sea snails, marine gastropod mollusks in the family Buccinidae. These snails are commonly known in the United States as whelks or Busycon whelks....
species and the North Atlantic Buccinum undatum
Buccinum undatum
Buccinum undatum, known as the common whelk, is a large edible marine gastropod in the family Buccinidae, the "true whelks".-Distribution:...
) and periwinkles including Littorina littorea.
There is enormous diversity within sea snails; many very different clades of gastropods are either dominated by, or consist exclusively of, sea snails. Because of this great variability, it is not possible to generalize about the feeding, reproduction, habitat and so on of sea snails. Instead it is necessary to look at the articles about individual clades, families, genera or species.
Shells
Limpet
Limpet is a common name for a number of different kinds of saltwater and freshwater snails ; it is applied to those snails that have a simple shell which is more or less conical in shape, and either is not spirally coiled, or appears not to be coiled in the adult snails.The name limpet is most...
s.
In one unusual family Juliidae
Juliidae
Juliidae, common name the bivalved gastropods, is a family of minute sea snails, marine gastropod mollusks or micromollusks in the superfamily Oxynooidea, an opisthobranch group....
, the shell of the snail has become two hinged plates closely resembling those of a bivalve; this family is sometimes called the "bivalved gastropods".
The shells of living species of sea snails range in size from Syrinx aruanus
Syrinx aruanus
Syrinx aruanus, common name the Australian trumpet or false trumpet, is a species of extremely large sea snail measuring up to 91 cm long and weighing up to 18 kg...
, the largest living shelled gastropod species, to minute species whose shells are under 1 mm at adult size.
Because in many cases the shells of sea snails are strong and durable, as a group they are well represented in the fossil record.
Anatomy
Sea snails are a very large group of animals and a very diverse one. Most snails that live in saltwater respire using a gillGill
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...
or gills, a few species however have a lung, are intertidal, and are active only at low tide when they can move around in the air. These air-breathing species include false limpets in the family Siphonariidae
Siphonariidae
Siphonariidae is a taxonomic family of small to medium-sized air-breathing sea snails, marine and brackish water pulmonate gastropod molluscs. These snails are sometimes known as "false limpets" because of the shape of the shell, but they are not at all closely related to true limpets...
and another group of false limpets in the family Trimusculidae
Trimusculidae
Trimusculus is a genus of medium-sized air-breathing sea snails or false limpets, marine pulmonate gastropod molluscs.Trimusculus is the only genus in the family Trimusculidae...
.
Many (but not all) sea snails have 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...
.
Human uses
A number of species of sea snails are exploited by humans for food, including abaloneAbalone
Abalone , from aulón, are small to very large-sized edible sea snails, marine gastropod molluscs in the family Haliotidae and the genus Haliotis...
, conch
Conch
A conch is a common name which is applied to a number of different species of medium-sized to large sea snails or their shells, generally those which are large and have a high spire and a siphonal canal....
, limpet
Limpet
Limpet is a common name for a number of different kinds of saltwater and freshwater snails ; it is applied to those snails that have a simple shell which is more or less conical in shape, and either is not spirally coiled, or appears not to be coiled in the adult snails.The name limpet is most...
s, whelk
Whelk
Whelk, also spelled welk or even "wilks", is a common name used to mean one or more kinds of sea snail. The species, genera and families referred to using this common name vary a great deal from one geographic area to another...
s (such as the North American Busycon
Busycon
Busycon is a genus of very large edible sea snails, marine gastropod mollusks in the family Buccinidae. These snails are commonly known in the United States as whelks or Busycon whelks....
species and the North Atlantic Buccinum undatum
Buccinum undatum
Buccinum undatum, known as the common whelk, is a large edible marine gastropod in the family Buccinidae, the "true whelks".-Distribution:...
) and periwinkles including Littorina littorea.
The shells of sea snails are often found by humans as one kind of seashell
Seashell
A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer created by an animal that lives in the sea. The shell is part of the body of the animal. Empty seashells are often found washed up on beaches by beachcombers...
that washes up on beach
Beach
A beach is a geological landform along the shoreline of an ocean, sea, lake or river. It usually consists of loose particles which are often composed of rock, such as sand, gravel, shingle, pebbles or cobblestones...
es. Because the shells of many sea snails are attractive and durable, they have been used by humans to make necklaces and other jewelry from prehistoric times to the current day.
The shells of a few species of large sea snails within the Vetigastropoda
Vetigastropoda
Vetigastropoda is a major taxonomic group of sea snails, marine gastropod mollusks that form a very ancient lineage. Taxonomically Vetigastropoda are sometimes treated as an order although they are a clade in Bouchet and Rocroi, 2005....
have a thick layer of nacre
Nacre
Nacre , also known as mother of pearl, is an organic-inorganic composite material produced by some mollusks as an inner shell layer; it is also what makes up pearls. It is very strong, resilient, and iridescent....
and have been exploited as a source of mother of pearl. Historically the button
Button
In modern clothing and fashion design, a button is a small fastener, most commonly made of plastic, but also frequently of seashell, which secures two pieces of fabric together. In archaeology, a button can be a significant artifact. In the applied arts and in craft, a button can be an example of...
industry relied on these species for a number of years.
Use by other animals
The shells of sea snails are used for protection by many kinds of hermit crabHermit crab
Hermit crabs are decapod crustaceans of the superfamily Paguroidea. Most of the 1100 species possess an asymmetrical abdomen which is concealed in an empty gastropod shell that is carried around by the hermit crab.-Description:...
s. A hermit crab carries the shell by grasping the central columella of the shell using claspers on the tip of its abdomen.
Definition
It is not always easy to decide whether some gastropods should be called sea snails. Some species that live in brackish water (such as certain neritidsNeritidae
Neritidae, common name the nerites, is a taxonomic family of small to medium-sized saltwater and freshwater snails which have a gill and a distinctive operculum, marine, brackish water and freshwater gastropod mollusks in the order Neritoida....
) can be listed as either freshwater snails or marine snails, and some species that live right at, or right above, the high tide level (for example species in the genus Truncatella), are sometimes considered to be sea snails and sometimes listed as land snails.
2005 taxonomy
The following cladogramCladogram
A cladogram is a diagram used in cladistics which shows ancestral relations between organisms, to represent the evolutionary tree of life. Although traditionally such cladograms were generated largely on the basis of morphological characters, DNA and RNA sequencing data and computational...
is an overview of the main clades of living gastropods based on the taxonomy of Bouchet & Rocroi
Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)
The taxonomy of the Gastropoda as it was revised by Philippe Bouchet and Jean-Pierre Rocroi is currently the most up-to-date overall system for classifying gastropod mollusks...
(2005), with taxa that contain saltwater or brackish water species marked in boldface (some of the highlighted taxa consist entirely of marine species, but some of them also contain freshwater or land species.)
- Clade PatellogastropodaPatellogastropodaPatellogastropoda, common name true limpets and historically called Docoglossa, is a major phylogenetic group of marine gastropods, seen either as a clade or as a taxonomic order.-Taxonomy:Patellogastropoda was proposed by David R...
- Clade VetigastropodaVetigastropodaVetigastropoda is a major taxonomic group of sea snails, marine gastropod mollusks that form a very ancient lineage. Taxonomically Vetigastropoda are sometimes treated as an order although they are a clade in Bouchet and Rocroi, 2005....
- Clade Cocculiniformia
- Clade NeritimorphaNeritimorphaNeritimorpha is a taxonomic grouping, an unranked clade of snails, gastropod mollusks. This grouping includes land snails, sea snails, some deepwater limpets, and also freshwater snails...
- Clade CycloneritimorphaCycloneritimorphaCycloneritimorpha is a clade of land snails, freshwater snails, and sea snails. These are gastropod molluscs within the larger clade Neritimorpha...
- Clade Cycloneritimorpha
- Clade CaenogastropodaCaenogastropodaCaenogastropoda is a taxonomic clade of a large diverse group of mostly marine gastropods.Caenogastropoda contains a majority of the families of shelled marine molluscs including such families as the periwinkles, cowries, wentletraps, moon snails, and cone snails.About 60% of all living gastropods...
- Informal group ArchitaenioglossaArchitaenioglossaArchitaenioglossa is a taxonomic group of snails which have gills and often an operculum. They are primarily land and freshwater gastropod mollusks within the clade Caenogastropoda....
- Clade SorbeoconchaSorbeoconchaSorbeoconcha is a taxonomic clade of snails, i.e. gastropods, mainly marine species with gills and opercula, within the clade Caenogastropoda.The taxon Sorbeoconcha was named by Winston Ponder and David R. Lindberg in 1997.-1997 taxonomy:...
- Clade HypsogastropodaHypsogastropodaAccording to the Taxonomy of the Gastropoda Hypsogastropoda is a clade of parasitic marine gastropods within the clade Caenogastropoda....
- Clade LittorinimorphaLittorinimorphaLittorinimorpha is a large clade of gastropods within Hypsogastropoda consisting primarily of marine species, but also aquatic and terrestrial species as well....
- Informal group PtenoglossaPtenoglossaThe Ptenoglossa is an informal taxonomic group of sea snails.It was considered paraphyletic or polyphyletic by Ponder and Lindberg in their classification of the molluscs.-Taxonomy:*Superfamily Epitonioidea**Family Epitoniidae**Family Janthinidae...
- Clade NeogastropodaNeogastropodaNeogastropoda is an unranked taxonomic clade of sea snails, marine gastropod mollusks. For many years prior to 2005 Neogastropoda was an order.- Description :...
- Clade Littorinimorpha
- Informal group Architaenioglossa
- Clade HeterobranchiaHeterobranchiaHeterobranchia, the heterobranchs or Euthyneura, is a taxonomic clade of snails and slugs, which includes species from the sea, the land and freshwater; marine, aquatic and terrestrial gastropod mollusks....
- Informal group Lower HeterobranchiaLower HeterobranchiaLower Heterobranchia, also known as the Allogastropoda, is a group of rather specialized, highly-evolved sea slugs and sea snails, within the clade Heterobranchia...
- Informal group OpisthobranchiaOpisthobranchiaOpisthobranchs are a large and diverse group of specialized complex marine gastropods previously united under Opisthobranchia within the Heterobranchia, but no longer considered to represent a monophyletic grouping...
- Clade CephalaspideaCephalaspideaThe suborder Cephalaspidea, also known as the headshield slugs and bubble snails, is a clade of sea slugs and bubble snails, marine gastropod mollusks within the larger clade Euopisthobranchia....
- Clade Thecosomata
- Clade Gymnosomata
- Clade Aplysiomorpha
- Group AcochlidiaceaAcochlidiaceaAcochlidiacea, common name acochlidians, are a taxonomic clade of very unusual sea snails and sea and freshwater slugs, aquatic gastropod mollusks within the large clade Heterobranchia...
- Clade SacoglossaSacoglossaSacoglossa, commonly known as the sacoglossans or the "sap-sucking sea slugs", are a clade of small sea slugs and sea snails, marine gastropod mollusks that belong to the clade Heterobranchia...
- Group Cylindrobullida
- Clade Umbraculida
- Clade NudipleuraNudipleuraNudipleura are a clade of sea snails and sea slugs, marine gastropod mollusks within the large clade Heterobranchia.- 2005 taxonomy :In the taxonomy of Bouchet & Rocroi , the clade Nudipleura is arranged as follows:*Clade Nudipleura...
- Clade Pleurobranchomorpha
- Clade Nudibranchia
- Clade EuctenidiaceaEuctenidiaceaThe Euctenidiacea are a taxonomic family of sea snails or slugs, marine gastropod molluscs in the order Notaspidea.A phylogenetical study, published in 2000, by Wägele & Willan has shown that the subclade Gnathodoridacea and the subclade Doridacea each form a monophyletic group.In a later study,...
- Clade DexiarchiaDexiarchiaThe Dexiarchia are a clade of sea slugs, shell-less marine gastropod molluscs in the clade Nudipleura.This classification is based on the study by Schrödl et al., published in 2001, who recognized within this clade two clades Pseudoeuctenidiacea and Cladobranchia.- Clade Pseudoeuctenidiacea ...
- Clade Pseudoeuctenidiacea
- Clade CladobranchiaCladobranchiaThe Cladobranchia are a taxonomic clade of nudibranch sea snails or slugs, marine gastropod molluscs in the clade Dexiarchia.-Taxonomy:**Family Charcotiidae**Family Dironidae**Family Dotidae**Family Embletoniidae**Family Goniaeolididae**Family Heroidae...
- Clade Euarminida
- Clade Dendronotida
- Clade AeolididaAeolididaThe Aeolidida is a taxonomic clade of sea slugs, specifically aeolid nudibranchs, marine gastropod molluscs in the clade Cladobranchia.-Taxonomy:*Superfamily Flabellinoidea Bergh, 1889**Family Flabellinidae**Family Notaeolidiidae...
- Clade Euctenidiacea
- Clade Cephalaspidea
- Informal group PulmonataPulmonataThe Pulmonata, or "pulmonates", are an informal group of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills...
- Informal group BasommatophoraBasommatophoraBasommatophora was a term that was previously used as a taxonomic informal group, a group of snails within the informal group Pulmonata, the air-breathing slugs and snails...
- Clade EupulmonataEupulmonataThe Eupulmonata is a taxonomic clade of air-breathing snails. The great majority of this group are land snails and slugs, but some are marine and some are saltmarsh snails that can tolerate salty conditions.-Linnean taxonomy:...
- Clade SystellommatophoraSystellommatophoraThe Systellommatophora is a clade of primitive, air-breathing slugs according to the taxonomy of the Gastropoda...
- Clade StylommatophoraStylommatophoraStylommatophora is a taxon of air-breathing land snails and slugs, terrestrial pulmonate gastropod molluscs. This taxon is currently considered to be a clade. It was previously regarded as an infraorder...
- Clade ElasmognathaElasmognathaElasmognatha is a taxonomic grouping, a clade, of air-breathing land snails and slugs, terrestrial pulmonate gastropod molluscs.A number of species in this taxonomic group are endangered.- Taxonomy :...
- Clade OrthurethraOrthurethraOrthurethra is a clade of terrestrial pulmonate gastropods .In the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005, Orthurethra is treated as an informal group and subclade of Stylommatophora.- Taxonomy :...
- Informal group SigmurethraSigmurethraSigmurethra is a taxonomic category of air-breathing land snails and slugs, terrestrial pulmonate gastropod molluscs. This is an Informal Group which includes the majority of land snails and slugs....
- Clade Elasmognatha
- Clade Systellommatophora
- Informal group Basommatophora
- Informal group Lower Heterobranchia
Cultural references
In the animated American TV series SpongeBob SquarePantsSpongeBob SquarePants
SpongeBob SquarePants is an American animated television series, created by marine biologist and animator Stephen Hillenburg. Much of the series centers on the exploits and adventures of the title character and his various friends in the underwater city of "Bikini Bottom"...
, the main character SpongeBob
SpongeBob SquarePants (character)
SpongeBob SquarePants is a main fictional character in the animated television series SpongeBob SquarePants. He is voiced by Tom Kenny and first appeared on television in the series' pilot episode "Help Wanted" on May 1, 1999. SpongeBob was created and designed by cartoonist Stephen Hillenburg...
has a pet sea snail called Gary
Gary (SpongeBob SquarePants)
Garold "Gary" Star the Snail is a fictional character in the American animated TV series SpongeBob SquarePants. The character is an anthropomorphic sea snail created and designed by animator Stephen Hillenburg and voiced by Tom Kenny...
. Gary makes a "meow" vocalization like a cat. The character's eyes are well-developed and colorful, similar to the eyes of species in the sea snail family Strombidae
Strombidae
Strombidae, commonly known as the true conchs, is a taxonomic family of medium-sized to very large sea snails, marine gastropod mollusks in the superfamily Stromboidea....
.