Strombidae, commonly known as the true conchs, is a

taxonomic Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. A ...

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideal ...

of medium-sized to very large

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ab ...

s in the superfamily Stromboidea, and the Epifamily Neostromboidae. The term true conchs, being a common name, does not have an exact meaning. It may refer generally to any of the Strombidae but sometimes is used more specifically to include only ''Strombus'' and ''Lambis''. The family currently includes 26

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extin ...

, and 10

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genera.

Distribution

Strombid gastropods live mainly in

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

and

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...

waters. These animals are widespread in the

Indo-West Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

, where most species and genera occur. Nearly 40 of the living species that used to belong to the genus ''

Strombus ''Strombus'' is a genus of medium to large sea snails, marine gastropod molluscs in the family Strombidae, which comprises the true conchs and their immediate relatives. The genus ''Strombus'' was named by Swedish Naturalist Carl Linnaeu ...

'' can be found in the Indo-Pacific region.Abbott, R.T. (1960). "The genus Strombus in the Indo-Pacific". ''Indo-Pacific Mollusca'' 1(2): 33-144 They also occur in the eastern

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

and Western

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the "Old World" of Africa, Europe a ...

, and a single species can be found on the

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

n Atlantic coast. Six species of strombids are found in the wider

Caribbean The Caribbean (, ) ( es, El Caribe; french: la Caraïbe; ht, Karayib; nl, De Caraïben) is a region of the Americas that consists of the Caribbean Sea, its islands (some surrounded by the Caribbean Sea and some bordering both the Caribbean S ...

region, including the queen conch '' Aliger gigas'', the goliath conch '' Titanostrombus goliath'', the hawk-wing conch '' Lobatus raninus'', the rooster tail conch '' Aliger gallus'', the milk conch '' Macrostrombus costatus'', the West Indian fighting conch '' Strombus pugilis'', and the Florida fighting conch '' Strombus alatus''. Until recently, all of these species were placed in the genus ''Strombus'', but now many species are being moved into new genera.

Morphology and life habits

Strombids have long eye stalks. The shell of a strombid has a long and narrow

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An op ...

and a

siphonal canal The siphonal canal is an anatomical feature of the shells of certain groups of sea snails within the clade Neogastropoda. Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water is ...

. The shell margin has an indentation near the anterior end which accommodates one of the eye stalks. This indentation is called a strombid or

stromboid notch The stromboid notch is an anatomical feature which is found in the shell of one taxonomic family of medium-sized to large sea snails, the conches. Marine gastropods in the family Strombidae have a notch in the edge of the shell aperture not far ...

. The stromboid notch may be more or less conspicuous, depending on the species. The shells of most species in this family grow a flared lip upon reaching sexual maturity, and they lay eggs in long, gelatinous strands. The genera ''Strombus'' and ''Lambis'' have many similarities between them, both anatomical and reproductive, though their shells show some conspicuous differences. Strombids were widely accepted as

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

s by several authors in the 19th century, an erroneous concept that persisted for several decades into the first half of the 20th century. This ideology was probably born in the writings of

Lamarck Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck (1 August 1744 – 18 December 1829), often known simply as Lamarck (; ), was a French naturalist, biologist, academic, and soldier. He was an early proponent of the idea that biolog ...

, who classified strombids alongside other supposedly carnivorous snails, and was copied in this by subsequent authors. However, the many claims of those authors were never supported by the observation of animals feeding in their natural

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

. Nowadays, strombids are known to be specialized

herbivore A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthp ...

s and occasional

detritivore Detritivores (also known as detrivores, detritophages, detritus feeders, or detritus eaters) are heterotrophs that obtain nutrients by consuming detritus (decomposing plant and animal parts as well as feces). There are many kinds of invertebrates, ...

s. They are usually associated with shallow-water

reef A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock o ...

s and

seagrass meadow A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and ...

Behavior

Unlike most snails, which glide slowly across the substrate on their feet, strombid gastropods have a characteristic means of locomotion, using their pointed, sickle-shaped, horny operculum to propel themselves forward in a so-called leaping motion.Parker, G. H. (1922). "The leaping of the stromb (''Strombus gigas'' Linn.)". ''Journal of Experimental Zoology'' 36: 205-209. Burrowing behavior, in which an individual sinks itself entirely or partially into the substrate, is also frequent among strombid gastropods. The burrowing process itself, which involves distinct sequential movements and sometimes complex behaviors, is very characteristic of each species. Usually, large strombid gastropods, such as the queen conch ''

Eustrombus gigas ''Aliger gigas,'' originally known as ''Strombus gigas'' or more recently as ''Lobatus gigas'', commonly known as the queen conch, is a species of large sea snail, a marine gastropod mollusc in the family of true conches, the Strombidae. This ...

'' and the spider conch '' Lambis lambis'', do not bury themselves, except during their juvenile stages. However, smaller species such as '' Strombus canarium'' and '' Strombus epidromis'' may bury themselves even after adulthood.

Taxonomy

For a long time, all conchs and their allies (the strombids) were classified in only two genera, namely ''Strombus'' and ''Lambis''. This classification can still be found in many textbooks and on websites on the internet. Based on

molecular phylogeny Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

in addition to an extensively documented fossil record, both genera have been subdivided into several new genera by different authors.

Genera

The family Strombidae actually comprises 26 extant genera and 10 extinct genera (marked with a dagger †). ;Extant genera File:Lobatus gigas 01.jpg, '' Aliger gigas'' File:Canarium mutabile forma zebriolatus 01.JPG, '' Canarium mutabile'' File:Conomurex decorus 01.jpg, '' Conomurex decorus'' File:Doxander vittatus entropi 01.JPG, '' Doxander vittatus'' File:Euprotomus aurisdianae 01.JPG, '' Euprotomus aurisdianae'' File:Gibberulus gibbosus 01.JPG, '' Gibberulus gibbosus'' File:Harpago chiragra 01.JPG, '' Harpago chiragra'' File:Laevistrombus canarium canarium 01.JPG, ''

Laevistrombus canarium ''Laevistrombus canarium'' ( commonly known as the dog conch or by its better-known synonym, ''Strombus canarium'') is a species of edible sea snail, a marine gastropod mollusc in the family Strombidae (true conches). Known from illustrations ...

'' File:Lambis scorpius indomaris 01.JPG, '' Lambis scorpius'' File:Lentigo lentiginosus 01.JPG, '' Lentigo lentiginosus'' File:Mirabilistrombus listeri 01.JPG, '' Mirabilistrombus listeri'' File:Margistrombus marginatus marginatus 01.JPG, '' Neodilatilabrum marginatus'' File:Sinustrombus sinuatus, Bohol, Philippines.jpg, '' Sinustrombus sinuatus'' File:Strombus pugilis 01.JPG, '' Strombus pugilis'' File:Terestrombus terebellatus 01.JPG, '' Terestrombus terebellatus'' File:WLA hmns Strombus thersites.jpg, '' Thersistrombus thersites'' File:Tridentarius dentatus 01.jpg, '' Tridentarius dentatus'' ;Extinct genera ;Genera brought into synonymy * ''Afristrombus'' Bandel, 2007 is a synonym of ''Persististrombus'' Kronenberg & Lee, 2007 * ''Aliger'' Thiele, 1929 is a synonym of ''Lobatus'' Swainson, 1837 * ''Decostrombus'' Bandel, 2007 is a synonym of ''Conomurex'' Bayle in P. Fischer, 1884 * ''Eustrombus'' Wenz, 1940 is a synonym of ''Lobatus'' Swainson, 1837 * ''Fusistrombus'' Bandel, 2007 is a synonym of ''Canarium'' Schumacher, 1817 * ''Gallinula'' Mörch, 1852 is a synonym of ''Labiostrombus'' Oostingh, 1925 * ''Hawaiistrombus'' Bandel, 2007 is a synonym of ''Canarium'' Schumacher, 1817 * ''Heptadactylus'' Mörch, 1852 is a synonym of ''Lambis'' Röding, 1798 * ''Latissistrombus'' Bandel, 2007 is a synonym of ''Sinustrombus'' Bandel, 2007 * ''Millipes'' Mörch, 1852 is a synonym of ''Lambis'' Röding, 1798 * ''Ministrombus'' Bandel, 2007 is a synonym of ''Dolomena'' Wenz, 1940 * ''Monodactylus'' Mörch, 1852 is a synonym of ''Euprotomus'' Gill, 1870 * ''Margistrombus'' Bandel, 2007 is a synonym of ''Neodilatilabrum'' Dekkers, 2008 * ''Pterocera'' Lamarck, 1799 is a synonym of ''Lambis'' Röding, 1798 * ''Pyramis'' Röding, 1798 is a synonym of ''Strombus'' Linnaeus, 1758 * ''Solidistrombus'' Dekkers, 2008 is a synonym of ''Sinustrombus'' Bandel, 2007 * ''Strombella'' Schlüter, 1838 is a synonym of ''Strombus'' Linnaeus, 1758 * ''Strombidea'' Swainson, 1840 is a synonym of ''Canarium'' Schumacher, 1817

Phylogeny

The most recent revision of Maxwell 2019 (ZooKeys 867:1-7) new crown clade Neostromboidae to separate the Strombidae, Rostellariidae, and Seraphsidae from their sister families Struthiolariidae and Aporrhaidae. There is significant value to understanding evolutionary processes within Stromboidea to recognise the universal similarity in the position of the eye on the end of peduncles and a diminished cephalic tentacle that arises from the middle to the end on that peduncle. This is in contrast to other members of the Stromboidea where the eye is located at the base of the cephalic tentacle. These physiological differences represent two set of organisms with divergent and independent evolutionary life histories and therefore these differences need to be identifiable within the nomenclature to bring meaning to the way we name things.new crown clade Neostromboidae to separate the Strombidae, Rostellariidae, and Seraphsidae from their sister families Struthiolariidae and Aporrhaidae. There is significant value to understanding evolutionary processes within Stromboidea to recognise the universal similarity in the position of the eye on the end of peduncles and a diminished cephalic tentacle that arises from the middle to the end on that peduncle. This is in contrast to other members of the Stromboidea where the eye is located at the base of the cephalic tentacle. (from Maxwell et al. 2019) (https://www.researchgate.net/publication/334746905_Recognising_and_defining_a_new_crown_clade_within_Stromboidea_Rafinesque_1815_Mollusca_Gastropoda) Historically the phylogenetic relationships among the Strombidae have been mainly accessed on two occasions, using two methods. In a 2005

monograph A monograph is a specialist work of writing (in contrast to reference works) or exhibition on a single subject or an aspect of a subject, often by a single author or artist, and usually on a scholarly subject. In library cataloging, ''monogra ...

, Simone proposed a

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

(a tree of descent) based on an extensive

morpho The morpho butterflies comprise many species of Neotropical butterfly under the genus ''Morpho''. This genus includes more than 29 accepted species and 147 accepted subspecies, found mostly in South America, Mexico, and Central America. ''Mo ...

anatomical Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its ...

analysis of representatives of the

Aporrhaidae Aporrhaidae is a family of sea snails commonly called the "pelican's foot snails." The taxonomy of the Gastropoda by Bouchet & Rocroi, 2005Bouchet P. & Rocroi J.-P. (Ed.); Frýda J., Hausdorf B., Ponder W., Valdes A. & Warén A. 2005. ''Classif ...

, Strombidae,

Xenophoridae Xenophoridae, commonly called carrier shells, is a family of medium-sized to large sea snails, marine gastropod mollusks in the clade Littorinimorpha. According to the taxonomy of the Gastropoda by Bouchet & Rocroi (2005) the family Xenophor ...

, and Struthiolariidae. In his analysis, Simone recognized the Strombidae as a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...

taxon supported by 13

synapomorphies In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to hav ...

(traits that are shared by two or more

taxa In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...

and their

most recent common ancestor In biology and genetic genealogy, the most recent common ancestor (MRCA), also known as the last common ancestor (LCA) or concestor, of a set of organisms is the most recent individual from which all the organisms of the set are descended. The ...

), comprising at least eight distinct genera. He considered the genus '' Terebellum'' as the most basal

taxon In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular n ...

, distinguished from the remaining strombids by 13 synapomorphies, including a rounded foot. Though the genus ''

Tibia The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...

'' was left out of the analysis, Simone regarded it as probably closely related to '' Terebellum'', apparently due to some well known morphological similarities between them. With the exception of ''Lambis'', the remaining taxa were previously allocated within the genus ''

''. However, according to Simone, only '' Strombus gracilior'', '' Strombus alatus'', and '' Strombus pugilis'', the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen( ...

, remained within ''Strombus'', as they constituted a distinct group based on at least five synapomorphies. The remaining taxa were previously considered as

subgenera In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...

, and were elevated to genus level by Simone in the end of his analysis. The genus '' Eustrombus'' (now considered a synonym of '' Lobatus''), in this case, included ''Eustrombus gigas'' (now considered a synonym of ''

Lobatus gigas ''Aliger gigas,'' originally known as ''Strombus gigas'' or more recently as ''Lobatus gigas'', commonly known as the queen conch, is a species of large sea snail, a marine gastropod mollusc in the family of true conches, the Strombidae. This ...

'') and ''Eustrombus goliath'' (= '' Lobatus goliath''); similarly, the genus '' Aliger'' included ''Aliger costatus'' (= '' Lobatus costatus'') and ''Aliger gallus'' (= '' Lobatus gallus'').

A different approach, this time based on sequences of nuclear

histone H3 Histone H3 is one of the five main histones involved in the structure of chromatin in eukaryotic cells. Featuring a main globular domain and a long N-terminal tail, H3 is involved with the structure of the nucleosomes of the 'beads on a strin ...

and mitochondrial cytochrome-c oxidase I (COI) genes was proposed by Latiolais and colleagues in a 2006 paper. The analysis included 32 strombid species that used to, or still belong in the genera ''Strombus'' and ''Lambis''.Latiolais J. M., Taylor M. S., Roy K. & Hellberg M. E. (2006). "A molecular phylogenetic analysis of strombid gastropod morphological diversity". ''

Molecular Phylogenetics and Evolution ''Molecular Phylogenetics and Evolution'' is a peer-reviewed scientific journal of evolutionary biology and phylogenetics. The journal is edited by E.A. Zimmer. Indexing The journal is indexed in: *EMBiology EMBiology is a bibliographic databas ...

'' 41: 436-444.
PDF

Human use

Snails in the family Strombidae are used by humans in a wide range of ways, mostly as food or decoration. Several species belonging to numerous genera among the Strombidae are considered economically important. Some species have been used in human culture for centuries. Since before the

Age of Discovery The Age of Discovery (or the Age of Exploration), also known as the early modern period, was a period largely overlapping with the Age of Sail, approximately from the 15th century to the 17th century in European history, during which seafarin ...

, strombid shells were used as

wind instruments A wind instrument is a musical instrument that contains some type of resonator (usually a tube) in which a column of air is set into vibration by the player blowing into (or over) a mouthpiece set at or near the end of the resonator. The pitch ...

, and were later used in the lime industry, in handicrafts, as souvenirs, and even in jewelry. In the

Bermuda ) , anthem = " God Save the King" , song_type = National song , song = " Hail to Bermuda" , image_map = , map_caption = , image_map2 = , mapsize2 = , map_caption2 = , subdivision_type = Sovereign state , subdivision_name = , ...

and southeastern

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territo ...

, the queen conch '' Aliger gigas'' is sought after for its conch pearls, which have been used in jewelry since the

Victorian era In the history of the United Kingdom and the British Empire, the Victorian era was the period of Queen Victoria's reign, from 20 June 1837 until her death on 22 January 1901. The era followed the Georgian period and preceded the Edwardi ...

. Image:Die Flügelschnecken (Strombea) - in Abbildungen nach der Natur mit Beschreibungen (1845) (20292533424).jpg Image:Die Flügelschnecken (Strombea) - in Abbildungen nach der Natur mit Beschreibungen (1845) (20292538204).jpg Image:Die Flügelschnecken (Strombea) - in Abbildungen nach der Natur mit Beschreibungen (1845) (20292539754).jpg Image:Die Flügelschnecken (Strombea) - in Abbildungen nach der Natur mit Beschreibungen (1845) (20727155968).jpg Image:Die Flügelschnecken (Strombea) - in Abbildungen nach der Natur mit Beschreibungen (1845) (20888850646).jpg Image:Die Flügelschnecken (Strombea) - in Abbildungen nach der Natur mit Beschreibungen (1845) (20888857476).jpg Image:Die Flügelschnecken (Strombea) - in Abbildungen nach der Natur mit Beschreibungen (1845) (20922430931).jpg

References

External links

Gastropoda Stromboidea - Ulrich Wieneke and Han Stoutjesdijk

Worldwide Conchology Strombidae

- photographs * The difference between a conch and a whel

{{Taxonbar, from=Q732932 Strombidae, Stromboidea Taxa named by Constantine Samuel Rafinesque Gastropod families