Queen conch
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''Aliger gigas,'' originally known as ''Strombus gigas'' or more recently as ''Lobatus gigas'', commonly known as the queen conch, is a
species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of large sea snail, a marine gastropod mollusc in the
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. Idea ...
of true conches, the
Strombidae Strombidae, commonly known as the true conchs, is a taxonomic family of medium-sized to very large sea snails in the superfamily Stromboidea, and the Epifamily Neostromboidae. The term true conchs, being a common name, does not have an exact me ...
. This species is one of the largest molluscs native to the Caribbean Sea, and tropical northwestern Atlantic, from
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 = , es ...
to
Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
, reaching up to in shell length. ''A. gigas'' is closely related to the goliath conch, '' Lobatus goliath'', a species
endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...
to Brazil, as well as the rooster conch, '' Aliger gallus''. The queen conch is
herbivorous 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 mouthpar ...
. It feeds by browsing for plant and algal material growing in the
seagrass Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the or ...
beds, and scavenging for decaying plant matter. These large sea snails typically reside in seagrass beds, which are sandy plains covered in swaying sea grass and associated with coral reefs, although the exact habitat of this species varies according to developmental age. The adult animal has a very large, solid and heavy
shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...
, with knob-like spines on the shoulder, a flared, thick outer lip, and a characteristic pink or orange
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 ...
(opening). The outside of the queen conch is sandy colored, helping them blend in with their surroundings. The flared lip is absent in juveniles; it develops once the snail reaches reproductive age. The thicker the shell's flared lip is, the older the conch is. The external
anatomy 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 it ...
of the soft parts of ''A. gigas'' is similar to that of other snails in the family Strombidae; it has a long snout, two
eyestalk In anatomy, an eyestalk (sometimes spelled eye stalk and also known as an ommatophore) is a protrusion that extends an eye away from the body, giving the eye a better field of view. It is a common feature in nature and frequently appears in fic ...
s with well-developed eyes, additional sensory
tentacles In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work mainl ...
, a strong foot and a
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. The word is generally used to describe natural or pathological anatomical structures made out ...
,
sickle A sickle, bagging hook, reaping-hook or grasshook is a single-handed agricultural tool designed with variously curved blades and typically used for harvesting, or reaping, grain crops or cutting Succulent plant, succulent forage chiefly for feed ...
-shaped operculum. The shell and soft parts of living ''A. gigas'' serve as a home to several different kinds of
commensal Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit fro ...
animals, including slipper snails,
porcelain crab Porcelain crabs are decapod crustaceans in the widespread family Porcellanidae, which superficially resemble true crabs. They have flattened bodies as an adaptation for living in rock crevices. They are delicate, readily losing limbs when attack ...
s and a specialized species of
cardinalfish Cardinalfishes are a family, Apogonidae, of ray-finned fishes found in the Atlantic, Indian, and Pacific Oceans; they are chiefly marine, but some species are found in brackish water and a few (notably '' Glossamia'') are found in fresh water. A ...
known as the conchfish '' Astrapogon stellatus''. Its
parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...
s include
coccidia Coccidia (Coccidiasina) are a subclass of microscopic, spore-forming, single-celled obligate intracellular parasites belonging to the apicomplexan class Conoidasida. As obligate intracellular parasites, they must live and reproduce within an ...
ns. The queen conch's natural predators include several species of large
predatory Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...
sea snails, octopus, starfish,
crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...
s and
vertebrate Vertebrates () comprise all animal taxa within the subphylum Vertebrata () (chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with c ...
s (
fish Fish are aquatic, craniate, gill-bearing 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. Approximately 95% of ...
,
sea turtle Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhe ...
s,
nurse shark The nurse shark (''Ginglymostoma cirratum'') is an elasmobranch fish in the family Ginglymostomatidae. The conservation status of the nurse shark is globally assessed as Vulnerable in the IUCN List of Threatened Species. They are considered t ...
s). It is an especially important food source for large predators like sea turtles and nurse sharks. Human capture and consumption dates back into prehistory. Its shell is sold as a
souvenir A souvenir (), memento, keepsake, or token of remembrance is an object a person acquires for the memories the owner associates with it. A souvenir can be any object that can be collected or purchased and transported home by the traveler as a m ...
and used as a decorative object. Historically, Native Americans and indigenous Caribbean peoples used parts of the shell to create various tools. International trade in the Caribbean queen conch is regulated under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (
CITES CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...
) agreement, in which it is listed as ''Strombus gigas''. This species is not endangered in the Caribbean as a whole, but is commercially threatened in numerous areas, largely due to extreme overfishing.


Taxonomy and etymology


History

The queen conch was originally described from a shell in 1758 by Swedish naturalist and
taxonomist In biology, taxonomy () is the scientific study of naming, defining ( circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxa (singular: taxon) and these groups are give ...
Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his Nobility#Ennoblement, ennoblement in 1761 as Carl von Linné#Blunt, Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalise ...
, who originated the system of
binomial nomenclature In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...
. Linnaeus named the species ''Strombus gigas'', which remained the accepted name for over 200 years. Linnaeus did not mention a specific locality for this species, giving only "America" as the type locality. The specific name is the
ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...
word ' (), which means "giant", referring to the large size of this snail compared with almost all other gastropod molluscs. ''Strombus lucifer'', which was considered to be a synonym much later, was also described by Linnaeus in ''Systema Naturae''. In the first half of the 20th century, the
type material In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes t ...
for the species was thought to have been lost; in other words, the shell on which Linnaeus based his original description and which would very likely have been in his own collection, was apparently missing, which created a problem for taxonomists. To remedy this, in 1941 a
neotype In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the ...
of this species was designated by the American
malacologist Malacology is the branch of invertebrate zoology that deals with the study of the Mollusca (mollusks or molluscs), the second-largest phylum of animals in terms of described species after the arthropods. Mollusks include snails and slugs, clams, ...
s
William J. Clench William James Clench (24 October 1897 – 22 February 1984) was an American malacologist, professor at Harvard University and curator of the mollusk collection in the malacology department of the Museum of Comparative Zoology at Harvard. Early l ...
and
R. Tucker Abbott Robert Tucker Abbott (September 28, 1919 – November 3, 1995) was an American conchologist (seashells) and malacologist (molluscs). He was the author of more than 30 books on malacology, which have been translated into many languages. Abbot ...
. In this case, the neotype was not an actual shell or whole
specimen Specimen may refer to: Science and technology * Sample (material), a limited quantity of something which is intended to be similar to and represent a larger amount * Biological specimen or biospecimen, an organic specimen held by a biorepository ...
, but a figure from a 1684 book ', published 23 years before Linnaeus was born by the Italian Jesuit scholar Filippo Buonanni (1638–1723). This was the first book that was solely about seashells. In 1953 the Swedish malacologist
Nils Hjalmar Odhner Nils Hjalmar Odhner (6 December 1884 – 12 June 1973) was a Swedish zoologist who studied mollusks, a malacologist. He was professor of invertebrate zoology at the Swedish Museum of Natural History, Stockholm, and a member of the Royal Swedish Aca ...
searched the Linnaean Collection at
Uppsala University Uppsala University ( sv, Uppsala universitet) is a public research university in Uppsala, Sweden. Founded in 1477, it is the oldest university in Sweden and the Nordic countries still in operation. The university rose to significance during ...
and discovered the missing type shell, thereby invalidating Clench and Abbott's neotype designation.
Strombidae Strombidae, commonly known as the true conchs, is a taxonomic family of medium-sized to very large sea snails in the superfamily Stromboidea, and the Epifamily Neostromboidae. The term true conchs, being a common name, does not have an exact me ...
's taxonomy was extensively revised in the 2000s and a few subgenera, including '' Eustrombus'', were elevated to
genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
level by some authors. Petuch and Petuch and Roberts recombined this species as ''Eustrombus gigas'', and Landau and collaborators (2008) recombined it as ''Lobatus gigas''. In 2020, it was recombined as ''Aliger gigas'' by Maxwell and colleagues, which is the current valid name according to the
World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialis ...
.


Phylogeny

The
phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...
relationships among the Strombidae were mainly studied by Simone (2005) and Latiolais (2006), using two distinct methods. 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. ''Morph ...
- anatomical analysis of representatives of
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, which included ''A. gigas'' (there referred to as ''Eustrombus gigas''). With the exception of '' Lambis'' and '' Terebellum'', the remaining taxa were previously allocated in the genus ''Strombus'', including ''A. gigas''. 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 specime ...
, remained within ''Strombus'', as they constituted a distinct group based on at least five synapomorphies (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 ...
). The remaining taxa were previously considered subgenera and were elevated to genus level by Simone. Genus ''Eustrombus'' (now considered a synonym of '' Lobatus''), in this case, included ''Eustrombus gigas'' (now considered a synonym of ''Aliger gigas'') and ''Eustrombus goliath'' (= '' Lobatus goliath''), which were thus considered closely related. In a different approach, Latiolais and colleagues (2006) proposed another cladogram that attempts to show the phylogenetic relationships of 34 species within the family Strombidae. The authors analysed 31 ''Strombus '' species, including ''Aliger gigas'' (there referred to as ''Strombus gigas''), and three species in the allied genus ''Lambis''. The cladogram was based on DNA sequences of both 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 stri ...
and mitochondrial cytochrome-c oxidase I (COI) protein-coding
gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
regions. In this proposed phylogeny, ''Strombus gigas'' and ''Strombus gallus'' (= '' Lobatus gallus'') are closely related and appear to share a
common ancestor Common descent is a concept in evolutionary biology applicable when one species is the ancestor of two or more species later in time. All living beings are in fact descendants of a unique ancestor commonly referred to as the last universal comm ...
.


Common names

Common names include "queen conch" and "pink conch" in English, ' and ' in
Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
, ', ', ' and ' in
Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...
, ', ' in the
Dominican Republic The Dominican Republic ( ; es, República Dominicana, ) is a country located on the island of Hispaniola in the Greater Antilles archipelago of the Caribbean region. It occupies the eastern five-eighths of the island, which it shares with ...
and Grenada, and ' in
Puerto Rico Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and unincorporated ...
.


Anatomy


Shell

The mature
shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...
grows to in length in three to five years while the maximum reported size is . However, even though they only grow to be this maximum length, the thickness of the shell is constantly increasing. The shell is very solid and heavy, with 9 to 11
whorls A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral ...
and a widely flaring and thickened outer lip. The thickness is highly important because the thicker the shell, the better protected it is. Additionally, instead of increasing in size once it reaches its maximum, the outside shell thickens as time goes on- an important indicator of how old the queen conch is. Although this notch is not as well developed as elsewhere in the family, the shell feature is nonetheless visible in an adult dextral (normal right-handed) specimen, as a secondary anterior indentation in the lip, to the right of the siphonal canal (viewed ventrally). The animal's left eyestalk protrudes through this notch. The
spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spires a ...
is a protruding part of the shell that includes all of the whorls except the largest and final whorl (known as the body whorl). It is usually more elongated than in other strombid snails, such as the closely related and larger goliath conch, ''Lobatus goliath'' that is endemic to Brazil. In ''A. gigas'', the glossy finish or glaze around the
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 ...
of the adult shell is primarily in pale shades of pink. It may show a cream, peach or yellow colouration, but it can also sometimes be tinged with a deep
magenta Magenta () is a color that is variously defined as pinkish- purplish- red, reddish-purplish-pink or mauvish-crimson. On color wheels of the RGB (additive) and CMY (subtractive) color models, it is located exactly midway between red and blu ...
, shading almost to red. The periostracum, a layer of protein (
conchiolin Conchiolins (sometimes referred to as conchins) are complex proteins which are secreted by a mollusc's outer epithelium (the mantle). These proteins are part of a matrix of organic macromolecules, mainly proteins and polysaccharides, that ass ...
) that is the outermost part of the shell surface, is thin and a pale brown or tan colour. The overall shell morphology of ''A. gigas'' is not solely determined by the animal's genes; environmental conditions such as location, diet, temperature and depth, and biological interactions such as predation, can greatly affect it.Tewfik, A. (1991)."An assessment of the biological characteristics, abundance, and potential yield of the queen conch (''Strombus gigas'' L.) fishery on the Pedro Bank off Jamaica". ''Thesis submitted in partial fulfilment of the requirements for the Degree of Masters of Science (Biology)''. Acadia University, Canada. Juvenile conches develop heavier shells when exposed to predators. Conches also develop wider and thicker shells with fewer but longer spines in deeper water. The shells of juvenile queen conches are strikingly different in appearance from those of the adults. Noticeable is the complete absence of a flared outer lip; juvenile shells have a simple sharp
lip The lips are the visible body part at the mouth of many animals, including humans. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech. Human lips are a tactile sensory organ, and can be ...
, which gives the shell a conical or
biconic Many shapes have metaphorical names, i.e., their names are metaphors: these shapes are named after a most common object that has it. For example, "U-shape" is a shape that resembles the letter U, a bell-shaped curve has the shape of the vertical ...
outline. In
Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
, juvenile queen conches are known as "rollers", because wave action very easily rolls their shells, whereas it is nearly impossible to roll an adult specimen, due to its shell's weight and asymmetric profile. Subadult shells have a thin flared lip that continues to increase in thickness until death. Conch shells are about 95% calcium carbonate and 5% organic matter.


Historic illustrations

' (published in 1742 by the Italian
physician A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...
and malacologist
Niccolò Gualtieri Niccolò Gualtieri (9 July 1688 – 15 February 1744) was an Italian doctor and malacologist. He established a private natural history collection, and catalogued its contents, the best known being of the molluscs. Gualtieri was born in Florenc ...
) contains three illustrations of adult shells from different perspectives. The knobbed spire and the flaring outer lip, with its somewhat wing-like contour expanding out from the last whorl, is a striking feature of these images. The shells are shown as if balancing on the edge of the lip and/or the apex; this was presumably done for artistic reasons as these shells cannot balance like this. One of the most prized shell publications of the 19th century, a series of books titled ' (published by the French naturalist Jean-Charles Chenu from 1842 to 1853), contains illustrations of both adult and juvenile ''A. gigas'' shells and one uncoloured drawing depicting some of the animal's soft parts. Almost forty years later, a colored illustration from the ''Manual of Conchology'' (published in 1885 by the American malacologist
George Washington Tryon George Washington Tryon Jr. (20 May 1838 – 5 February 1888) 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 ...
) shows a dorsal view of a small juvenile shell with its typical brown and white patterning.


Soft parts

Many details about the anatomy of ''Aliger gigas'' were not well known until Colin Little's 1965 general study.abstract
In 2005, R. L. Simone gave a detailed anatomical description. ''A. gigas'' has a long extensible snout with two eyestalks (also known as ommatophores) that originate from its base. The tip of each eyestalk contains a large, well-developed lensed eye, with a black
pupil The pupil is a black hole located in the center of the Iris (anatomy), iris of the Human eye, eye that allows light to strike the retina.Cassin, B. and Solomon, S. (1990) ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing ...
and a yellow
iris Iris most often refers to: *Iris (anatomy), part of the eye *Iris (mythology), a Greek goddess * ''Iris'' (plant), a genus of flowering plants * Iris (color), an ambiguous color term Iris or IRIS may also refer to: Arts and media Fictional ent ...
and a small, slightly posterior sensory tentacle. Amputated eyes completely regenerate. Inside the mouth of the animal is a radula (a tough ribbon covered in rows of microscopic teeth) of the taenioglossan type. Both the snout and the eyestalks show dark spotting in the exposed areas. The mantle is darkly coloured in the anterior region, fading to light gray at the posterior end, while the mantle collar is commonly orange. The siphon is also orange or yellow. When the soft parts of the animal are removed from the shell, several organs are distinguishable externally, including the kidney, the nephiridial gland, the
pericardium The pericardium, also called pericardial sac, is a double-walled sac containing the heart and the roots of the great vessels. It has two layers, an outer layer made of strong connective tissue (fibrous pericardium), and an inner layer made o ...
, the genital glands, stomach, style sac and the digestive gland. In adult males, the penis is also visible.


Foot/locomotion

The species has a large and powerful foot with brown spots and markings towards the edge, but is white nearer to the visceral hump that stays inside the shell and accommodates internal organs. The base of the anterior end of the foot has a distinct groove, which contains the opening of the pedal gland. Attached to the posterior end of the foot for about one third of its length is the dark brown,
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. The word is generally used to describe natural or pathological anatomical structures made out ...
,
sickle A sickle, bagging hook, reaping-hook or grasshook is a single-handed agricultural tool designed with variously curved blades and typically used for harvesting, or reaping, grain crops or cutting Succulent plant, succulent forage chiefly for feed ...
-shaped operculum, which is reinforced by a distinct central rib. The base of the posterior two-thirds of the animal's foot is rounded; only the anterior third touches the ground during locomotion. The
columella Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire. His ' in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the wo ...
, the central pillar within the shell, serves as the attachment point for the white columellar muscle. Contraction of this strong muscle allows the animal's soft parts to shelter in the shell in response to undesirable stimuli. ''Aliger gigas'' has an unusual means of
locomotion Locomotion means the act or ability of something to transport or move itself from place to place. Locomotion may refer to: Motion * Motion (physics) * Robot locomotion, of man-made devices By environment * Aquatic locomotion * Flight * Locomo ...
, first described in 1922 by George Howard Parker (1864–1955). The animal first fixes the posterior end of the foot by thrusting the point of the sickle-shaped operculum into the substrate, then it extends the foot in a forward direction, lifting and throwing the shell forward in a so-called leaping motion. This way of moving is considered to resemble that of
pole vaulting Pole vaulting, also known as pole jumping, is a track and field event in which an athlete uses a long and flexible pole, usually made from fiberglass or carbon fiber, as an aid to jump over a bar. Pole jumping competitions were known to the M ...
, making ''A. gigas'' a good climber even of vertical concrete surfaces. This leaping locomotion may help prevent predators from following the snail's chemical traces, which would otherwise leave a continuous trail on the substrate.abstract


Life cycle

''Aliger gigas'' is
gonochoristic In biology, gonochorism is a sexual system where there are only two sexes and each individual organism is either male or female. The term gonochorism is usually applied in animal species, the vast majority of which are gonochoric. Gonochorism c ...
, which means each individual snail is either distinctly male or distinctly female. Females are usually larger than males in natural populations, with both sexes existing in similar proportion. After
internal fertilization Internal fertilization is the union of an egg and sperm cell during sexual reproduction inside the female body. Internal fertilization, unlike its counterpart, external fertilization, brings more control to the female with reproduction. For inte ...
, the females lay eggs in gelatinous strings, which can be as long as . These are layered on patches of bare sand or seagrass. The sticky surface of these long egg strings allows them to coil and agglutinate, mixing with the surrounding sand to form compact egg masses, the shape of which is defined by the anterior portion of the outer lip of the female's shell while they are layered. Each one of the egg masses may have been fertilized by multiple males. The number of eggs per egg mass varies greatly depending on environmental conditions such as food availability and temperature. Commonly, females produce 8–9 egg masses per season, each containing 180,000–460,000 eggs, but numbers can be as high as 750,000 eggs. ''A. gigas'' females may spawn multiple times during the reproductive season, which lasts from March to October, with activity peaks occurring from July to September. Queen conch
embryos An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...
hatch 3–5 days after spawning. At the moment of hatching, the protoconch (
embryonic Embryonic may refer to: *Of or relating to an embryo * ''Embryonic'' (album), a 2009 studio album by the Flaming Lips *''Embryonics ''Embryonics'' is a double-CD compilation of tracks by the Australian progressive metal band, Alchemist. It w ...
shell) is translucent and has a creamy, off-white background color with small, pustulate markings. This coloration is different from other Caribbean ''Lobatus'', such as ''
Lobatus raninus ''Lobatus raninus'', common name the hawk-wing conch, is a species of medium to large sea snail, a marine gastropod mollusk in the family Strombidae, the true conchs.Bouchet, P. (2010). Lobatus raninus (Gmelin, 1791). Accessed through: World ...
'' and '' Lobatus costatus'', which have unpigmented embryonic shells. Afterwards, the emerging two-lobed
veliger A veliger is the planktonic larva of many kinds of sea snails and freshwater snails, as well as most bivalve molluscs (clams) and tusk shells. Description The veliger is the characteristic larva of the gastropod, bivalve and scaphopod ...
(a larval form common to various marine and fresh-water gastropod and bivalve mollusks) spend several days developing in the
plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucia ...
, feeding primarily on phytoplankton. Metamorphosis occurs some 16–40 days from the hatching, when the fully grown protoconch is about 1.2 mm high. After the metamorphosis, ''A. gigas'' individuals spend the rest of their lives in the benthic zone (on or in the sediment surface), usually remaining buried during their first year of life. The queen conch reaches sexual maturity at approximately 3 to 4 years of age, reaching a shell length of nearly 180 mm and weighing up to 5 pounds. Individuals may usually live up to 7 years, though in deeper waters their lifespan may reach 20–30 years and maximum lifetime estimates reach 40 years.NOA
"Queen Conch (''Strombus gigas'')"
Retrieved 4 July 2009.
It is believed that the
mortality rate Mortality rate, or death rate, is a measure of the number of deaths (in general, or due to a specific cause) in a particular population, scaled to the size of that population, per unit of time. Mortality rate is typically expressed in units of d ...
tends to be lower in matured conchs due to their thickened shell, but it could be substantially higher for juveniles. Estimates have demonstrated that its mortality rate decreases as its size increases and can also vary due to habitat, season and other factors.


Ecology


Distribution

''Aliger gigas'' is native to the tropical Western Atlantic coasts of North and Central America in the greater Caribbean tropical zone. Although the species undoubtedly occurs in other places, this species has been recorded within the
scientific literature : ''For a broader class of literature, see Academic publishing.'' Scientific literature comprises scholarly publications that report original empirical and theoretical work in the natural and social sciences. Within an academic field, scie ...
as occurring, in: Aruba, ( Netherlands Antilles);
Barbados Barbados is an island country in the Lesser Antilles of the West Indies, in the Caribbean region of the Americas, and the most easterly of the Caribbean Islands. It occupies an area of and has a population of about 287,000 (2019 estimate) ...
;
the Bahamas The Bahamas (), officially the Commonwealth of The Bahamas, is an island country within the Lucayan Archipelago of the West Indies in the North Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to 88% of the ar ...
;
Belize Belize (; bzj, Bileez) is a Caribbean and Central American country on the northeastern coast of Central America. It is bordered by Mexico to the north, the Caribbean Sea to the east, and Guatemala to the west and south. It also shares a wate ...
;
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 = , es ...
; North and northeastern regions of Brazil (though this is contested); Old Providence Island in Colombia; Costa Rica; the Dominican Republic;
Panama Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Co ...
; Swan Islands in Honduras;
Jamaica Jamaica (; ) is an island country situated in the Caribbean Sea. Spanning in area, it is the third-largest island of the Greater Antilles and the Caribbean (after Cuba and Hispaniola). Jamaica lies about south of Cuba, and west of His ...
;
Martinique Martinique ( , ; gcf, label=Martinican Creole, Matinik or ; Kalinago: or ) is an island and an overseas department/region and single territorial collectivity of France. An integral part of the French Republic, Martinique is located in ...
; Alacran Reef, Campeche, Cayos Arcas and
Quintana Roo Quintana Roo ( , ), officially the Free and Sovereign State of Quintana Roo ( es, Estado Libre y Soberano de Quintana Roo), is one of the 31 states which, with Mexico City, constitute the 32 federal entities of Mexico. It is divided into 11 mu ...
, in Mexico; Puerto Rico;
Saint Barthélemy Saint Barthélemy (french: Saint-Barthélemy, ), officially the Collectivité territoriale de Saint-Barthélemy, is an overseas collectivity of France in the Caribbean. It is often abbreviated to St. Barth in French, and St. Barts in English ...
;
Mustique Mustique is a small private island in the nation of Saint Vincent and the Grenadines, which is part of the Grenadines, a chain of islands in the West Indies. The island is located within Grenadines Parish, and the closest island is the uninhab ...
and Grenada in the Grenadines;
Pinar del Río Pinar del Río is the capital city of Pinar del Río Province, Cuba. With a population of 139,336 (2004) in a municipality of 190,332, it is the 10th-largest city in Cuba. Inhabitants of the area are called ''Pinareños''. History Pinar del R ...
, North Havana Province, North Matanzas, Villa Clara, Cienfuegos,
Holguín Holguín () is a municipality and city in Cuba, and the capital of Province of Holguín. After Havana, Santiago de Cuba, and Camagüey, it is the fourth largest city in Cuba. History Before Columbus, the Taino people settled in huts made fro ...
,
Santiago de Cuba Santiago de Cuba is the second-largest city in Cuba and the capital city of Santiago de Cuba Province. It lies in the southeastern area of the island, some southeast of the Cuban capital of Havana. The municipality extends over , and contains ...
and Guantánamo, in the
Turks and Caicos The Turks and Caicos Islands (abbreviated TCI; and ) are a British Overseas Territory consisting of the larger Caicos Islands and smaller Turks Islands, two groups of tropical islands in the Lucayan Archipelago of the Atlantic Ocean and n ...
Islands and
Cuba Cuba ( , ), officially the Republic of Cuba ( es, República de Cuba, links=no ), is an island country comprising the island of Cuba, as well as Isla de la Juventud and several minor archipelagos. Cuba is located where the northern Caribbea ...
;
South Carolina )'' Animis opibusque parati'' ( for, , Latin, Prepared in mind and resources, links=no) , anthem = " Carolina";" South Carolina On My Mind" , Former = Province of South Carolina , seat = Columbia , LargestCity = Charleston , LargestMetro = ...
,
Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
, with the Florida Keys and Flower Garden Banks National Marine Sanctuary, in the United States; Carabobo, Falcon, Gulf of Venezuela,
Los Roques archipelago The Los Roques Archipelago (Spanish: ''Archipiélago de Los Roques'') is a federal dependency of Venezuela consisting of approximately 350 islands, cays, and islets in a total area of 40.61 square kilometers. The archipelago is located dir ...
, Los Testigos Islands and Sucre in Venezuela; all islands of the
United States Virgin Islands The United States Virgin Islands,. Also called the ''American Virgin Islands'' and the ''U.S. Virgin Islands''. officially the Virgin Islands of the United States, are a group of Caribbean islands and an unincorporated and organized territory ...
.


Habitat

''Aliger gigas'' lives at depths from 0.3–18 m to 25–35 m. Its depth range is limited by the distribution of
seagrass Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the or ...
and algae cover. In heavily exploited areas, the queen conch is more abundant in the deepest range. The queen conch lives in
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 ...
s and on sandy substrate,Ulrich Wieneke (ed.
''Lobatus gigas''
In: Gastropoda Stromboidea. modified: 22 November 2008. Retrieved 23 June 2009.
usually in association with turtle grass (species of the genus '' Thalassia'', specifically ''Thalassia testudinum''Davis, J.E. (2003)
"Population assessment of queen conch, ''Strombus gigas'', in the St. Eustatius Marine Park, Netherlands Antilles"
. St. Eustatius Marine Park.
and also '' Syringodium'' sp.) and
manatee Manatees (family Trichechidae, genus ''Trichechus'') are large, fully aquatic, mostly herbivorous marine mammals sometimes known as sea cows. There are three accepted living species of Trichechidae, representing three of the four living speci ...
grass ('' Cymodocea'' sp.). Juveniles inhabit shallow, inshore seagrass meadows, while adults favor deeper algal plains and seagrass meadows. The critical
nursery habitats In marine environments, a nursery habitat is a subset of all habitats where juveniles of a species occur, having a greater level of productivity per unit area than other juvenile habitats (Beck et al. 2001). Mangroves, salt marshes and seagrass ar ...
for juvenile individuals are defined by a series of characteristics, including tidal circulation and
macroalgal Seaweed, or macroalgae, refers to thousands of species of Macroscopic scale, macroscopic, Multicellular organism, multicellular, ocean, marine algae. The term includes some types of ''Rhodophyta'' (red), ''Brown algae, Phaeophyta'' (brown) and ...
production, which together enable high rates of recruitment and survival. ''A. gigas'' is typically found in distinct aggregates that may contain several thousand individuals.McCarthy, K. (2007)
"A review of queen conch (''Strombus gigas'') life-history''
Sustainable Fisheries Division NOAA. ''SEDAR 14-DW-4''.


Diet

Strombid gastropods 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 s ...
s by several authors in the 19th century, a concept that persisted until the first half of the 20th century. This erroneous idea originated in the writings of
Jean-Baptiste 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 biolo ...
, who classified strombids with other supposedly carnivorous snails. This idea was subsequently repeated by other authors, but had not been supported by observation. Subsequent studies have refuted the concept, proving beyond doubt that strombid gastropods are
herbivorous 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 mouthpar ...
animals. In common with other Strombidae, ''Aliger gigas'' is a specialized herbivore, that feeds on
macroalgae Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of '' Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...
(including red algae, such as species of ''
Gracilaria ''Gracilaria'' is a genus of red algae (Rhodophyta) notable for its economic importance as an agarophyte, as well as its use as a food for humans and various species of shellfish. Various species within the genus are cultivated among Asia, South ...
'' and ''
Hypnea ''Hypnea'' is a genus of red algae, and a well known carrageenophyte (plant producing polysaccharide carrageenan). Taxonomy and Nomenclature ''Hypnea'' is a genus of red seaweed under class Florideophyceae, order Gigartinales, and family Cys ...
''), Tryon, G.W. (1885). ''
Manual of Conchology George Washington Tryon Jr. (20 May 1838 – 5 February 1888) 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. ...
, structural and systematic, with illustrations of the species
Volume 7
Terebridae, Cancellariidae, Strombidae, Cypraeidae, Ovulidae, Cassididae, Doliidae.'' p
107348
seagrass and
unicellular A unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists of multiple cells. Organisms fall into two general categories: prokaryotic organisms and ...
algae, intermittently also feeding on algal detritus. The green macroalgae '' Batophora oerstedii'' is one of its preferred foods.


Interactions

A few different animals establish
commensal Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit fro ...
interactions with ''A. gigas'', which means that both organisms maintain a relationship that benefits (the commensal) species but not the other (in this case, the queen conch). Commensals of this species include certain mollusks, mainly slipper shells ('' Crepidula'' spp.) The
porcelain crab Porcelain crabs are decapod crustaceans in the widespread family Porcellanidae, which superficially resemble true crabs. They have flattened bodies as an adaptation for living in rock crevices. They are delicate, readily losing limbs when attack ...
'' Porcellana sayana'' is also known to be a commensal and a small
cardinalfish Cardinalfishes are a family, Apogonidae, of ray-finned fishes found in the Atlantic, Indian, and Pacific Oceans; they are chiefly marine, but some species are found in brackish water and a few (notably '' Glossamia'') are found in fresh water. A ...
, known as the conch fish ('' Astrapogon stellatus''), sometimes shelters in the conch's mantle for protection. ''A. gigas'' is very often parasitized by
protist A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the exc ...
s of the phylum
Apicomplexa The Apicomplexa (also called Apicomplexia) are a large phylum of parasitic alveolates. Most of them possess a unique form of organelle that comprises a type of non-photosynthetic plastid called an apicoplast, and an apical complex structure. Th ...
, which are common mollusk parasites. Those coccidian parasites, which are spore-forming, single-celled
microorganism A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...
s, initially establish themselves in large vacuolated
cell Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery ...
s of the host's
digestive gland The hepatopancreas, digestive gland or midgut gland is an organ of the digestive tract of arthropods and molluscs. It provides the functions which in mammals are provided separately by the liver and pancreas, including the production of digestive e ...
, where they reproduce freely. The infestation may proceed to the secretory cells of the same organ. The entire life cycle of the parasite typically occurs within a single host and tissue. ''Aliger gigas'' is a
prey Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...
species for several carnivorous gastropod mollusks, including the apple murex ''
Phyllonotus pomum ''Phyllonotus pomum'' , the apple murex, is a species of large sea snail, a marine gastropod mollusk in the family Muricidae, the murex snails or rock snails. Description The size of an adult shell varies between 44 mm and 133 mm. O ...
'', the horse conch ''
Triplofusus papillosus ''Triplofusus giganteus'', previously known as ''Pleuroploca gigantea'', common name the Florida horse conch, is a species of extremely large predatory subtropical and tropical sea snail, a marine gastropod mollusc in the family Fasciolariidae, ...
'', the lamp shell '' Turbinella angulata'', the moon snails '' Natica'' spp. and '' Polinices'' spp., the muricid snail '' Phyllonotus margaritensis'', the trumpet triton ''
Charonia variegata ''Charonia variegata'', the Atlantic triton or Atlantic triton's trumpet, is a species of predatory sea snail, a marine gastropod mollusk in the family Charoniidae, the triton snails, triton shells, or tritons. Distribution This species has ...
'' and the tulip snail ''
Fasciolaria tulipa ''Fasciolaria tulipa'', common name the true tulip, is a species of large sea snail, a marine gastropod mollusk in the family Fasciolariidae. Distribution This species occurs from the North Carolina coast all the way south and west to the Gul ...
''.
Crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...
s are also conch predators, such as the blue crab ''
Callinectes sapidus ''Callinectes sapidus'' (from the Ancient Greek ,"beautiful" + , "swimmer", and Latin , "savory"), the blue crab, Atlantic blue crab, or regionally as the Chesapeake blue crab, is a species of crab native to the waters of the western Atlantic ...
'', the box crab '' Calappa gallus'', the giant hermit crab '' Petrochirus diogenes'', the spiny lobster ''
Panulirus argus ''Panulirus argus'', the Caribbean spiny lobster, is a species of spiny lobster that lives on reefs and in mangrove swamps in the western Atlantic Ocean. Anatomy ''P. argus'' have long, cylindrical bodies covered with spines. Two large spines ...
'' and others.
Sea stars Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish ar ...
,
vertebrate Vertebrates () comprise all animal taxa within the subphylum Vertebrata () (chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with c ...
s,
horse conch ''Triplofusus giganteus'', previously known as ''Pleuroploca gigantea'', common name the Florida horse conch, is a species of extremely large predatory subtropical and tropical sea snail, a marine gastropod mollusc in the family Fasciolariidae, ...
, octopus,
eagle ray The eagle rays are a group of cartilaginous fishes in the family Myliobatidae, consisting mostly of large species living in the open ocean rather than on the sea bottom. Eagle rays feed on mollusks and crustaceans, crushing their shells with the ...
,
nurse shark The nurse shark (''Ginglymostoma cirratum'') is an elasmobranch fish in the family Ginglymostomatidae. The conservation status of the nurse shark is globally assessed as Vulnerable in the IUCN List of Threatened Species. They are considered t ...
,
fish Fish are aquatic, craniate, gill-bearing 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. Approximately 95% of ...
(such as the permit ''
Trachinotus falcatus The permit (''Trachinotus falcatus'') is a game fish of the western Atlantic Ocean belonging to the family Carangidae. Adults feed on crabs, shrimp, and smaller fish. Taxonomy The permit was first described by the "father of taxonomy", Carl L ...
'' and the porcupine fish ''
Diodon hystrix Porcupinefishes or balloonfishes, are any of the various species of the genus ''Diodon'', the type genus of Diodontidae. Distinguishing features Fish of the genus ''Diodon'' have: * two-rooted, movable spines (which are derived from modified s ...
''), loggerhead sea turtles (''
Caretta caretta The loggerhead sea turtle (''Caretta caretta'') is a species of oceanic turtle distributed throughout the world. It is a marine reptile, belonging to the family Cheloniidae. The average loggerhead measures around in carapace length when fully ...
'') and humans also eat the queen conch.


Uses

Conch meat has been consumed for centuries and has traditionally been an important part of the diet in many islands in the
West Indies The West Indies is a subregion of North America, surrounded by the North Atlantic Ocean and the Caribbean Sea that includes 13 independent island countries and 18 dependencies and other territories in three major archipelagos: the Greate ...
and Southern Florida. It is consumed raw, marinated, minced or chopped in a wide variety of dishes, such as
salad A salad is a dish consisting of mixed, mostly natural ingredients with at least one raw ingredient. They are typically served at room temperature or chilled, though some can be served warm. Condiments and salad dressings, which exist in a va ...
s,
chowder Chowder is a thick soup prepared with milk or cream, a roux, and seafood or vegetables. Oyster crackers or saltines may accompany chowders as a side item, and cracker pieces may be dropped atop the dish. New England clam chowder is typically ...
, fritters, soups, stew,
pâté ''Pâté'' ( , , ) is a paste, pie or loaf filled with a forcemeat. Common forcemeats include ground meat from pork, poultry, fish or beef; fat, vegetables, herbs, spices and either wine or brandy (often cognac or armagnac). It is often ser ...
s and other local recipes. In both English and Spanish-speaking regions, for example in the Dominican Republic, ''Aliger gigas'' meat is known as '. Although conch meat is used mainly for human consumption, it is also sometimes employed as
fishing bait Fishing bait is any substance used to attract and catch fish, e.g. on a fishing hook. Bait items are both selected from and placed within the environment to achieve enhanced prey capture success. Traditionally, fishing baits are natural fish foo ...
(usually the foot). ''A. gigas'' is among the most important fishery resources in the Caribbean: its harvest value was US$30 million in 1992, increasing to $60 million in 2003.CITES (2003)
''Review of Significant Trade in specimens of Appendix-II species. (Resolution Conf. 12.8 and Decision 12.75)''
. Nineteenth meeting of the Animals Committee,
Geneva , neighboring_municipalities= Carouge, Chêne-Bougeries, Cologny, Lancy, Grand-Saconnex, Pregny-Chambésy, Vernier, Veyrier , website = https://www.geneve.ch/ Geneva ( ; french: Genève ) frp, Genèva ; german: link=no, Genf ; it, Ginevr ...
(Switzerland), 18–21.
The total annual harvest of meat of ''A. gigas'' ranged from 6,519,711 kg to 7,369,314 kg between 1993 and 1998, later production declined to 3,131,599 kg in 2001. Data about US imports shows a total of 1,832,000 kg in 1998, as compared to 387,000 kg in 2009, a nearly 80% reduction twelve years later. Queen conch shells were used by Native Americans and Caribbean Indians in a wide variety of ways. South Florida bands (such as the
Tequesta The Tequesta (also Tekesta, Tegesta, Chequesta, Vizcaynos) were a Native American tribe. At the time of first European contact they occupied an area along the southeastern Atlantic coast of Florida. They had infrequent contact with Europeans a ...
), the Carib, the
Arawak The Arawak are a group of indigenous peoples of northern South America and of the Caribbean. Specifically, the term "Arawak" has been applied at various times to the Lokono of South America and the Taíno, who historically lived in the Great ...
and
Taíno The Taíno were a historic indigenous people of the Caribbean whose culture has been continued today by Taíno descendant communities and Taíno revivalist communities. At the time of European contact in the late 15th century, they were the pri ...
used conch shells to fabricate tools (such as
knives A knife ( : knives; from Old Norse 'knife, dirk') is a tool or weapon with a cutting edge or blade, usually attached to a handle or hilt. One of the earliest tools used by humanity, knives appeared at least 2.5 million years ago, as evidenced ...
, axe heads and chisels),
jewelry Jewellery ( UK) or jewelry ( U.S.) consists of decorative items worn for personal adornment, such as brooches, rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the clothes. From a w ...
,
cookware Cookware and bakeware is food preparation equipment, such as cooking pots, pans, baking sheets etc. used in kitchens. Cookware is used on a stove or range cooktop, while bakeware is used in an oven. Some utensils are considered both cookware ...
and used them as
blowing horn The blowing horn or winding horn is a sound device that is usually made of or shaped like an animal horn, arranged to blow from a hole in the pointed end of it. This rudimentary device had a variety of functions in many cultures, in most cases r ...
s. In
Mesoamerican Mesoamerica is a historical region and cultural area in southern North America and most of Central America. It extends from approximately central Mexico through Belize, Guatemala, El Salvador, Honduras, Nicaragua, and northern Costa Rica. Withi ...
history, Aztecs used the shell as part of jewelry mosaics such as the double-headed serpent. The Aztecs also believed that the sound of trumpets made from queen conch shells represented divine manifestations, and used them in religious ceremonies. In central Mexico, during rain ceremonies dedicated to Tlaloc, the
Maya Maya may refer to: Civilizations * Maya peoples, of southern Mexico and northern Central America ** Maya civilization, the historical civilization of the Maya peoples ** Maya language, the languages of the Maya peoples * Maya (Ethiopia), a popul ...
used conch shells as hand protectors (in a manner similar to boxing gloves) during combat. Ancient
middens A midden (also kitchen midden or shell heap) is an old dump for domestic waste which may consist of animal bone, human excrement, botanical material, mollusc shells, potsherds, lithics (especially debitage), and other artifacts and ecofac ...
of ''L. gigas'' shells bearing round holes are considered an evidence that pre-Columbian Lucayan Indians in the Bahamas used the queen conch as a food source. Brought by explorers, queen conch shells quickly became a popular asset in early modern Europe. In the late 17th century they were widely used as decoration over fireplace mantels and
English garden The English landscape garden, also called English landscape park or simply the English garden (french: Jardin à l'anglaise, it, Giardino all'inglese, german: Englischer Landschaftsgarten, pt, Jardim inglês, es, Jardín inglés), is a sty ...
s, among other places. In contemporary times, queen conch shells are mainly utilized in handicraft. Shells are made into cameos, bracelets and lamps, and traditionally as
doorstop A doorstop (also door stopper, door stop or door wedge) is an object or device used to hold a door open or closed, or to prevent a door from opening too widely. The same word is used to refer to a thin slat built inside a door frame to prevent a ...
s or
decorations Decoration may refer to: * Decorative arts * A house painter and decorator's craft * An act or object intended to increase the beauty of a person, room, etc. * An award that is a token of recognition to the recipient intended for wearing Other ...
by families of seafaring men. The shell continues to be popular as a decorative object, though its export is now regulated and restricted by the
CITES CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...
agreement. In modern culture, queen conch shells are often represented in everyday objects such as coins and stamps. Very rarely (about 1 in 10,000 conchs), a conch pearl may be found within the mantle. Though these pearls occur in a range of colors corresponding to the colors of the interior of the shell, pink specimens are the most valuable. These pearls are considered semi-precious, and a popular tourist curio. The best specimens have been used to create necklaces and earrings. A conch pearl is a non- nacreous pearl (formerly referred to by some sources as a ' calcareous concretion'); it differs from most pearls that are sold as gemstones in that it is not iridescent. The
specific weight The specific weight, also known as the unit weight, is the weight per unit volume of a material. A commonly used value is the specific weight of water on Earth at , which is .National Council of Examiners for Engineering and Surveying (2005). ''Fu ...
of the conch pearl is 2.85, notably heavier than any other type. Due to the sensitive nature of the animal and the location of the pearl-forming portion of the snail within the spiral shell, commercial cultivation of pearls is considered virtually impossible. Research into the conch shell's unique architecture is currently under way at
MIT The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the m ...
.


Status


Threats

Queen conch populations have been rapidly declining throughout the years and have been mostly depleted in some areas in the Caribbean due to the fact that they are highly sought after for their meat and their value. Within the conch fisheries, one of the threats to sustainability stems from the fact that there is almost as much meat in large juveniles as there is in adults, but only adult conchs can reproduce, and thus sustain a population. In many places where adult conchs have become rare due to overfishing, larger juveniles and subadults are taken before they ever mate. In the United States (
Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
), it is currently illegal to gather or pick the queen conch either recreationally or commercially. In other parts of the world where it is legal, only adult conchs can be fished. The rule is to let each conch have ample time to reproduce before taken out of its habitat, potentially leading to a more stable population. However, this rule has not been followed by countless fishers. On a number of islands, subadults provide the majority of the harvest. The abundance of ''Aliger gigas'' is declining throughout its range as a result of overfishing and poaching. Especially because of overfishing, many pockets of conch communities fall below the critical level needed for reproducing. A 2019 study predicted overfishing could lead to the extinction of queen conchs in as little as ten years. Additionally, if the conch fishery collapses, it could potentially leave over 9,000 Bahamian fishers out of work. Trade from many Caribbean countries, such as
the Bahamas The Bahamas (), officially the Commonwealth of The Bahamas, is an island country within the Lucayan Archipelago of the West Indies in the North Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to 88% of the ar ...
, Antigua and Barbuda, Honduras, Haiti and the
Dominican Republic The Dominican Republic ( ; es, República Dominicana, ) is a country located on the island of Hispaniola in the Greater Antilles archipelago of the Caribbean region. It occupies the eastern five-eighths of the island, which it shares with ...
, is known or thought to be unsustainable. As of 2001, queen conch populations in at least 15 Caribbean countries and states were overfished or overexploited. Illegal harvest, including fishing in foreign waters and subsequent illegal international trade, is a common problem in the region. The Caribbean "International Queen Conch Initiative" is an international attempt at managing this species. On 13 January 2019, the Bahamas' Department of Marine Resources announced it would be making official recommendations to better protect the conch, including ending exports and increasing regulatory staff. Presently,
ocean acidification Ocean acidification is the reduction in the pH value of the Earth’s ocean. Between 1751 and 2021, the average pH value of the ocean surface has decreased from approximately 8.25 to 8.14. The root cause of ocean acidification is carbon dioxid ...
is another serious threat to the queen conch. Acidity levels are rising and adversely affecting shellfish larvae. Rising atmospheric CO2 levels result in rising levels of carbonic acid in seawater, which is particularly harmful to organisms with calcium carbonate shells and structures. Certain larval stages of shellfish are very sensitive to lower seawater pH.


Conservation

The queen conch fishery is usually managed under the regulations of individual nations. In the United States all taking of queen conch is prohibited in Florida and in adjacent Federal waters. No international regional fishery management organization exists for the whole Caribbean area, but in places such as Puerto Rico and the Virgin Islands, queen conch is regulated under the auspices of the Caribbean Fishery Management Council (CFMC). In 2014, the Parties to the Convention for the Protection and Development of the Marine Environment of the Wider Caribbean Region ( Cartagena Convention) included queen conch in Annex III of its Protocol Concerning Specially Protected Areas and Wildlife ( SPAW Protocol). Species included in the Annex III require special measures to be taken to ensure their protection and recovery, and their use is authorised and regulated accordingly. The species is listed in Appendix II of the
Convention on International Trade in Endangered Species CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...
(CITES) meaning international trade (import/export) in the species and its parts and derivatives is regulated by the CITES permitting system. The listing was proposed by the United States making queen conch the first large-scale fisheries product to be regulated by CITES (as ''Strombus gigas'').''Appendices I, II and III''
cites.org website. Retrieved 4 July 2009.
In 1995 CITES began reviewing the biological and trade status of the queen conch under its "Significant Trade Review" process. These reviews are undertaken to address concerns about trade levels in an Appendix II species. Based on the 2003 review, CITES recommended that all countries prohibit importation from Honduras, Haiti and the Dominican Republic, according to Standing Committee Recommendations. Queen conch meat continues to be available from other Caribbean countries, including Jamaica and Turks and Caicos, which operate well-managed queen conch fisheries. For conservation reasons, the Government of Colombia currently bans the commercialisation and consumption of the conch between the months of June and October. The
Bahamas National Trust The Bahamas National Trust is a non-profit organisation in the Bahamas that manages the country's 32 national parks.. Its headquarters is located in New Providence in the Bay Street Business Centre, East Bay Street. Its office was formally locate ...
is building awareness by educating teachers and students through workshops and an awareness campaign which includes the catchy pop son
''Conch Gone''


References


Further reading

* Coomans H.E. (1965). "Shells and shell objects from an Indian site on Magueyes Island, Puerto Rico". '' Caribbean Journal of Science'' 5 (1–2): 15–23
PDF
* *


External links

* * ARKive
images and movies of the queen conch (''Strombus gigas'')



Microdocs

Bermuda Department of Conservation Services (includes Queen Conch Recovery Plan)
* {{Taxonbar , from=Q62603 Strombidae Molluscs of the Atlantic Ocean Fauna of the Caribbean Arthropods of the Dominican Republic Gastropods described in 1758 Taxa named by Carl Linnaeus