Eustrombus gigas, previously known as
Strombus gigas, and having many common names including the
queen conch, is a
speciesIn biology, a species is:* a taxonomic rank or* a unit at that rank ....
of very large edible sea
snailThe word snail is a common name for almost all members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word snail is used in a general sense, it includes sea snails, land snails and freshwater snails. Snails lacking a shell or having only a very small one are...
, a marine gastropod mollusk in the
familyIn biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus...
StrombidaeStrombidae, common name the true conchs, is a taxonomic family of medium-sized to very large sea snails with an operculum. These are marine gastropod mollusks in the order Sorbeoconcha....
, the true conchs.
Eustrombus gigas is one of the largest mollusks native to the tropical "Caribbean faunal zone" of the Western
Atlantic OceanThe Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about 106.4 million square kilometres , it covers approximately one-fifth of the Earth's surface and about one-quarter of its water surface area. The first part of its name refers to the Atlas of Greek...
, from
BermudaBermuda is a British overseas territory in the North Atlantic Ocean. Located off the east coast of the United States, it is situated around 1,770 kilometres northeast of Miami, Florida, and 1,350 kilometres south of Halifax, Nova Scotia, Canada...
to
BrazilBrazil , officially the Federative Republic of Brazil , is a country in South America. It is the fifth largest country by geographical area, occupying nearly half of South America, the fifth most populous country, and the fourth most populous democracy in the world. Bounded by the Atlantic Ocean...
.
Common nameA common name is a name in general use within a community; it is often contrasted with a scientific name...
s for
Eustrombus gigas also include: pink conch, caracol reina, caracol rosa, caracol rosado, caracol de pala, cobo, botuto, guarura, and lambí.
The queen conch is protected under the CITES agreement, where it is listed as
Strombus gigas. This species is not yet truly endangered in the
CaribbeanThe Caribbean is a region consisting of the Caribbean Sea, its islands , and the surrounding coasts...
as a whole, but it is commerically threatened in many areas, partly because of extreme overfishing, as the meat is an important food source for humans.
The CITES regulations are designed to halt the export of the meat of this species from the Caribbean countries where it is found, as well as the commercial export of the shells as decorative objects. Both of these trades were previously so prevalent that they represented very serious threats to the survival of the species.
Etymology
The
specific nameIn zoological nomenclature, a specific name is the second part in the name of a species...
comes from the
GreekGreek , an independent branch of the Indo-European family of languages, is the language of the Greeks. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. In its ancient form, it is the language of classical...
gigasGigas is a Greek word meaning "giant", originally used to describe the race of Gigantes in Greek mythology.Gigas has become a popular term for races of giants in fantasy games. The name was first used in this sense in the Squaresoft game Final Fantasy I, and was subsequently used in many other...
(γίγας), which means giant, in a possible allusion to the extraordinary body size of this species.
Shell description
The adult
shellThe gastropod shell is a shell which is part of the body of a gastropod or snail. It is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
is from 15-31
cmA centimetre is a unit of length in the metric system, equal to one hundredth of a metre, which is the current SI base unit of length. Centi is the SI prefix for a factor of...
(6-12
inchAn inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot...
es) in length (the maximum reported size is 352 mm), very thick and heavy, and has a widely flaring and thickened outer lip. There is a
stromboid notchStrombidae, common name the true conchs, is a taxonomic family of medium-sized to very large sea snails with an operculum. These are marine gastropod mollusks in the order Sorbeoconcha....
on the outer lip. In life the left eyestalk protrudes through this notch.
The
spireA spire is a descriptive term for part of the shell of a snail, a gastropod mollusc shell or gastropod shell. The spire consists of all of the whorls of a coiled gastropod shell except for the body whorl....
of the shell is usually taller than that of other strombid species. The glossy finish around the aperture of the adult shell is colored primarily in shades of pink. The pink glaze is pale, and may sometimes show a cream, peach, or yellow coloration. It can also be tinged with a deep
magentaMagenta is a purplish-pink color evoked by lights with less power in yellowish-green wavelengths than in blue and red wavelengths . In light experiments, magenta can be produced by removing the lime-green wavelengths from white light...
, shading almost to red. The
periostracumPeriostracum is a thin organic coating or "skin" which is the outermost layer of the shell of many shelled mollusks. It is primarily seen in snails and clams, i.e. in bivalves and gastropods, but it is also found in cephalopods such as the nautilus...
is very thin, and colored pale tan.
Drawings of an adult shell of
Eustrombus gigas from
Index Testarum Conchyliorum (1742):
In contrast, the juvenile shells are a mottled brown and white color when small, and have a sharp lip with no flare at all. In
FloridaFlorida is a state located in the southeastern region of the United States, bordering Alabama to the northwest and Georgia to the north. It was the 27th state admitted to the United States...
the juveniles are known as "rollers", because wave action very easily rolls these shells, whereas it is nearly impossible to roll the adult shell of this species. The subadult shell has a flared lip which is very thin. The outer lip of an adult shell gradually increases its thickness with age. It is important to notice that the overall shell morphology of
E. gigas is not only determined by the animals genes, as environmental conditions (such as geographic location, nourishment and temperature) may greatly affect it.
Anatomy
Many details about the anatomy of
Eustrombus gigas were not well known until 1965, when Colin Little published an extensive study on the subject.
Head
Eustrombus gigas has a long, very extensible
snoutThe snout, or muzzle, is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw.-Terminology:The term "muzzle", used as a noun, can be ambiguous...
. Two
eyestalkIn anatomy, an eyestalk is a protrusion that extends the eye away from the body, giving the eye a better field of view than if it were unextended. It is common in nature and in fiction.- In nature :...
s rise from its base, each one of them containing a large well developed
lensThe lens is a transparent, biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina. The lens, by changing shape, functions to change the focal distance of the eye so that it can focus on objects at various distances, thus allowing a sharp real...
eye with a black
irisThe iris is a membrane in the eye, responsible for controlling the diameter and size of the pupil and the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel...
, and also a small tentacle near the anterior end. Its eyes can be completelly
regeneratedIn biology, an organism is said to regenerate a lost or damaged part if the part regrows so that the original function is restored.Regenerative capacity is inversely related to complexity: in general, the more complex an animal is the less regeneration it is capable of. Whereas newts, for example,...
. Both the snout and the eyestalks present dark spotting in the exposed areas. The
radulaThe radula is an anatomical structure found in mollusks and used for feeding. It is a minutely toothed, chitinous ribbon. It is typically used for scraping or cutting food before the food enters the esophagus...
inside the snout is of Taenioglossan type.
Mantle and visceral hump
The
mantleThe mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass....
is colored dark anteriorly, fading to light gray pigmentation posteriorly. The mantle collar is commonly orange in color, and the siphon is also colored orange or yellow. Many organs are distinguishable externally when the animal is removed from the shell, such as the kidney, the
nephiridialNephridia are invertebrate organs which function similar to kidneys. They remove metabolic wastes from an animal's body. They are present in many different invertebrate lines. There are two basic types, metanephridia and protonephridia, but there are other types.-Metanephridia:A metanephridium...
gland, the pericardium, the
genital glandsThe reproductive system of gastropods varies greatly from one group to another within this very large and diverse taxonomic class of animals...
, stomach, style sach, and the digestive gland.
Foot
Eustrombus gigas has a powerful and large foot, colored white towards the visceral hump, with brown and white disperse spots and markings by the base. The base of the anterior end of the foot has a distinct groove, which in fact 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 sickle-shaped
operculumThe operculum, meaning little lid, is a corneous or calcareous structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...
, which is reinforced by a distinct central rib. The base of the posterior two-thirds of the animals foot is rounded. Only the anterior third is applied to the substrate during locomotion. The white columellar muscle is large and very strong.
Peculiar locomotion
Eustrombus gigas has rather particular mean of locomotion. This curious series of maneuvers was first described by G. H. Parker in 1922.
The animal first fixes the posterior end of the foot by having the point of the sickle-shaped operculum thrust into the substrate. Then it extends of the foot anteriorly, further lifting and throwing of the shell forward in a so called leaping motion. The leaping motion makes
E. gigas a good climber of vertical cement surfaces, and may also help it inhibit predators from following its chemical traces over the substrate.
Distribution
Eustrombus gigas is native to north and Central America. It lives in the greater
CaribbeanThe Caribbean is a region consisting of the Caribbean Sea, its islands , and the surrounding coasts...
tropical zone, at depths from 0.3 m to 18 m.
The countries and regions where
Eustrombus gigas is found include:
ArubaAruba is a -long island of the Lesser Antilles in the southern Caribbean Sea, north of the Paraguaná Peninsula, Falcón State, Venezuela. Together with Bonaire and Curaçao, it forms a group referred to as the ABC islands of the Leeward Antilles, the southern island chain of the Lesser Antilles.An...
, of the Lesser Antilles;
BarbadosBarbados , situated just east of the Caribbean Sea, is an independent West Indian Continental Island-nation in the western Atlantic Ocean. For over three centuries Barbados was a colony and protectorate of the United Kingdom; and still currently maintains Queen Elizabeth II as head of state...
;
BiminiBimini is the westernmost district of the Bahamas composed of a chain of islands located about 53 miles due east of Miami, Florida. Bimini is the closest point in the Bahamas to the mainland United States and approximately 137 miles west-northwest of Nassau.-Geography:The largest islands are...
,
Cat Island-Islands:* Cat Island , Australia* Cat Island , Bahamas* Cat Island , Mauritius* Cat Island , United States* Cat Island , United States* Cat Island , United States...
,
EleutheraSee also: EleutheraeEleuthera is an island in The Bahamas, lying 50 miles east of Nassau. It is very long and thin—110 miles long and in places little more than a mile wide. According to the 2000 Census, the population of Eleuthera is approximately 8,000...
, Grand Bahama Island,
InaguaInagua is the southernmost district of the Bahamas comprising the islands of Great Inagua and Little Inagua.Great Inagua is the third largest island in The Bahamas at 596 sq mi and lies about 55 miles from the eastern tip of Cuba. The island is about 55 x 19 miles in extent, the highest point...
(Great or Little) and
Little San SalvadorLittle San Salvador Island, Bahamas , is one of about 700 islands that make up the archipelago of the Bahamas. It is located roughly between Eleuthera and Cat Island. It is a private island, owned wholly by Holland America Line, a subsidiary of Carnival Corporation & PLC...
in Bahamas;
BelizeBelize , is a country in Central America. Belize has a diverse society, composed of many cultures and speaking many languages. Although Kriol and Spanish are spoken among the population, Belize is the only country in Central America where English is the official language...
;
BermudaBermuda is a British overseas territory in the North Atlantic Ocean. Located off the east coast of the United States, it is situated around 1,770 kilometres northeast of Miami, Florida, and 1,350 kilometres south of Halifax, Nova Scotia, Canada...
; North and northeastern regions of
BrazilBrazil , officially the Federative Republic of Brazil , is a country in South America. It is the fifth largest country by geographical area, occupying nearly half of South America, the fifth most populous country, and the fourth most populous democracy in the world. Bounded by the Atlantic Ocean...
; Old Providence Island in
ColombiaColombia , officially the Republic of Colombia , is a constitutional republic in northwestern South America. Colombia is bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the northwest by Panama; and to the west by the Pacific Ocean...
; Costa Rica and
PanamaPanama, officially the Republic of Panama , is the southernmost country of both Central America and, in turn, North America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the...
;
Swan Island-Australia:* Little Swan Island, Tasmania, Australia* Swan Island , Australia* Swan Island , Australia-Falkland Islands:* Swan Islands, Falkland Islands* Weddell Island, formerly Swan Island, Falkland Islands-United Kingdom:...
in
HondurasHonduras is a republic in Central America. It was formerly known as Spanish Honduras to differentiate it from British Honduras...
;
JamaicaJamaica is an island nation of the Greater Antilles, in length and as much as in width, amounting to 11,100 km
2. It is situated in the Caribbean Sea, about south of Cuba, and west of Hispaniola, the island harboring the nation-states Haiti and the Dominican Republic...
;
MartiniqueMartinique is an island in the eastern Caribbean Sea, with a land area of . It is an overseas department of France. To the northwest lies Dominica, to the south St Lucia, and to the southeast Barbados. As with the other overseas departments, Martinique is also one of the twenty-six regions of...
;
Alacran Reef,
CampecheThe State of Campeche is a state in the south-east region of the Mexican Republic. It is bordered by the Mexican states of Yucatán to the north east, Quintana Roo to the east, and Tabasco to the south west...
,
Cayos ArcasThe Cayos Arcas is a chain of three tiny sand cays and an accompanying reef system in the Gulf of Mexico. It is located approximately 130 kilometers from the mainland, west of Campeche....
and
Quintana RooQuintana Roo is a state of Mexico, on the eastern part of the Yucatán Peninsula. It borders the States of Yucatán and Campeche to the north and west, the Caribbean Sea to the east, and the nation of Belize to the south...
, in
MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
;
Puerto RicoPuerto Rico , officially the Commonwealth of Puerto Rico , is a self-governing unincorporated territory of the United States located in the northeastern Caribbean, east of the Dominican Republic and west of the Virgin Islands...
; Saint Barthélemy;
MustiqueMustique is a small private island in the West Indies where the Caribbean Sea and the Atlantic Ocean meet. The island is one of a group of islands called the Grenadines, most of which form part of the country of St Vincent and the Grenadines.The island covers 1,400 acres and it has several coral...
and
GrenadaGrenada is an island country and sovereign state consisting of the island of Grenada and six smaller islands at the southern end of the Grenadines in the southeastern Caribbean Sea. Grenada is located northwest of Trinidad and Tobago, northeast of Venezuela, and southwest of Saint Vincent and the...
, in the
GrenadinesThe Grenadines are a Caribbean island chain of over 600 islands in the Windward Islands. They are divided between the island nations of Saint Vincent and the Grenadines and Grenada...
;
Pinar del RioPinar del Río is a city in Cuba. It is the capital of Pinar del Río Province.Inhabitants of the area are called Pinareños.Neighborhoods in the city include La Conchita, La Coloma, Briones Montoto and Las Ovas.-History:...
,
North Havana ProvinceHavana Province is one of the provinces of Cuba. It had 711 066 people in the 2002 census. The largest city is Artemisa .-Geography:...
, North
MatanzasMatanzas is the capital of the Cuban province of Matanzas. It is famed for its Afro-Cuban folklore.It is located on the northern shore of the island of Cuba, on the Bay of Matanzas , east of the capital Havana and west of the resort town of Varadero.Matanzas is called the city of bridges, of...
,
Villa ClaraVilla Clara may refer to:*Villa Clara Province, Cuba*Villa Clara, Entre Ríos, Argentina...
,
CienfuegosCienfuegos is a city on the southern coast of Cuba, capital of the province of Cienfuegos. It is located about 250 km from Havana, and has a population of 150,000. The city is dubbed "La Perla del Sur"...
,
HolguinHolguín is a municipality and city, the capital of the Cuban Province of Holguín.-History:It was founded as San Isidoro de Holguín in 1545, and it is named after its founder Captain García de Holguín, a Spanish military officer...
,
Santiago de CubaSantiago de Cuba is the capital city of Santiago de Cuba Province in the south-eastern area of the island nation of Cuba, some east south-east of the Cuban capital of Havana....
and
GuantanamoGuantánamo is a municipality and city in southeast Cuba and capital of Guantánamo Province.Guantánamo is served by the Caimanera port. Producing sugarcane and cotton wool are traditional parts of the economy.-Geography:...
, in
Turks and Caicos IslandsThe Turks and Caicos Islands are a British Overseas Territory consisting of two groups of sub-tropical islands in the West Indies, the larger Caicos Islands and the smaller Turks Islands, known for tourism and as an offshore financial centre.The Turks and Caicos Islands are situated about ...
and
CubaThe Republic of Cuba is an island country in the Caribbean. It consists of the island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city. Cuba is home to over 11 million people and is...
;
South CarolinaSouth Carolina is a U.S. state that borders Georgia to the south and North Carolina to the north. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence from the British Crown during the American Revolution. The colony was...
,
FloridaFlorida is a state located in the southeastern region of the United States, bordering Alabama to the northwest and Georgia to the north. It was the 27th state admitted to the United States...
, including
East FloridaEast Florida was originally a part of Spanish Florida. Under the terms of the Treaty of Paris , which ended the Seven Years' War, Spain ceded all of its territory east and southeast of the Mississippi River to the Kingdom of Great Britain....
,
West FloridaWest Florida was a region on the north shore of the Gulf of Mexico, which underwent several boundary and sovereignty changes during its history. Parts of the territory were held at various times by France, Spain, Britain, and the United States...
and
Florida KeysThe Florida Keys are a cluster of about 1700 islands in the southeast United States. They begin at the southeastern tip of the Florida peninsula, about south of Miami, and extend in a gentle arc south-southwest and then westward to Key West, the westernmost of the inhabited islands, and on to the...
, and Flower Garden Banks National Marine Sanctuary, in the USA;
CaraboboCarabobo is one of the 23 states of Venezuela, located in the north of the country, about 2 hours by car from Caracas. The capital city of this state is Valencia, which is also the country's main industrial center. The state's area is 4,650 km² and had an estimated population of 2,227,000 in...
,
FalconA falcon is any species of raptor in the genus Falco. The word comes from their Latin name falco, related to Latin falx because of the shape of these birds' wings.-Overview:...
,
Gulf of VenezuelaThe Gulf of Venezuela or gulf of Coquivacoa is a gulf of the Caribbean Sea bounded by the Venezuelan states of Zulia and Falcón and the Colombian department of Guajira...
,
Los Roques archipelagoThe Los Roques islands are a federal dependency of Venezuela, consisting of about 350 islands, cays or islets. The archipelago is an atoll located 80 miles directly north of the port of La Guaira, and is a 40-minute flight....
,
Los Testigos IslandsLos Testigos Islands are a group of islands in the southeastern Caribbean Sea. They are a part of the Dependencias Federales of Venezuela.-Geography:...
and
SucreSucre is the constitutional capital of Bolivia. Located in the south-central part of the country, Sucre lies at an altitude of 2750m . Its lower altitude gives the city a warm temperate climate year-round....
, in
VenezuelaVenezuela , officially titled Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It is a continental mainland with numerous islands located off its coastline in the Caribbean Sea...
and St. Croix in the
Virgin IslandsThe Virgin Islands are an archipelago, part of the Leeward Islands in the Caribbean Sea. The Leeward Islands are the northern islands of the Lesser Antilles, where the Caribbean Sea meets the western Atlantic Ocean....
.
Habitat
This large sea snail lives in
seagrassSeagrasses are flowering plants from one of four plant families , all in the order Alismatales , which grow in marine, fully-saline environments.-Ecology:These unusual marine flowering plants are called seagrasses because the leaves are long and narrow and are very...
meadows and on sandy
substrateIn biology a substrate is the surface a plant or animal lives upon. The substrate can include biotic or abiotic materials. For example, encrusting algae that lives on a rock can be substrate for another animal that lives above the algae on the rock. See also substrate .-External links:*...
, usually in association with turtle grass (namely,
Thalassia testudinum and
SyringodiumSyringodium is a genus in the family Cymodoceaceae. It includes two species distributed in warm oceans....
sp.). Juvenile individuals are found in shallow, inshore seagrass meadows, which are different from the deeper algal plains and seagrass meadows where adult individuals live.
Eustrombus gigas is customarily found in distinct aggregates, which may contain several thousand individuals.
Life cycle
Eustrombus gigas is
dioeciousDioecious species are whose members can produce only one type of gamete; each individual organism belonging to a dioecious species is distinctly male or female . The majority of animal species are dioecious...
, which means each individual organism belonging to this species is distinctly male or female. Females are usually larger than males in natural populations, and both sexes are present in similar proportion. After internal
fertilisationFertilisation , is the fusion of gametes to produce a new organism. In animals, the process involves a sperm fusing with an ovum, which eventually leads to the development of an embryo...
, the females lay eggs in gelatinous strings, which can be as long as 75 feet. These strings are layered on patches of bare sand or seagrass, and usually coil and agglutinate themselves to form compact egg masses. Each egg mass may be fertilized by multiple males, and the number of eggs per egg mass may vary greatly depending on environmental conditions, such as food limitation. Commonly, females produce an average of 8 egg masses per season, each of them containing 180,000 - 460,000 eggs, but numbers can be as high as 750,000 eggs per egg mass under given conditions.
Eustrombus gigas females may spawn several times during each reproductive season. After hatching, the emerging two lobed
veligerA veliger is the planktonic larva of many kinds of marine and fresh-water gastropod molluscs, as well as a number of bivalves .- Description :...
larvae spend several days developing in the
planktonPlankton consist of any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. Plankton are defined by their ecological niche rather than their phylogenetic or taxonomic classification...
, feeding primarily on
phytoplanktonPhytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτον , or "plant", and πλαγκτος , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
.
MetamorphosisMetamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation...
occurs in about 16-40 days from the hatching, when the fully grown
protoconchA protoconch is an embryonic or larval shell of some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod...
is about 1.2 mm high. After the metamorphosis,
Eustrombus gigas individuals spend the rest of their lives in the
benthic zoneThe benthic zone is the ecological region at the lowest level of a body of water such as an ocean or a lake, including the sediment surface and some sub-surface layers. Organisms living in this zone are called benthos. They generally live in close relationship with the substrate bottom; many such...
.
Eustrombus gigas is known to reach sexual maturity at approximately 3 to 4 years of age, reaching a shell length of nearly 180 mm and weighting up to 5 pounds.
Eustrombus gigas individuals may live up to 7 years. In deeper waters, they may live as long as 20-30 years. Estimation of lifetimes reaches 40 years.
Feeding habits
Eustrombus gigas is known to be an
herbivoreA herbivore is an animal that is adapted to eat plants and not meat.Herbivory is a form of predation in which an organism consumes principally autotrophs such as plants, algae and photosynthesizing bacteria....
, feeding on macroalgae (including
Sphaerococcus confervoides) and
epiphyteAn epiphyte is:Epiphyte is one of the subdivisions of the Raunkiær system. The term most commonly refers to higher plants, but epiphytic bacteria, fungi , algae, lichens, mosses, and ferns exist as well. The term epiphytic derives from the Greek epi- and phyton...
s, and sometimes also feeding on
detritusDetritus is a biological term used to describe dead or waste organic material.Detritus may also refer to:* Detritus , a geological term used to describe the particles of rock produced by weathering...
. The green macroalga
Batophora oerstedi is notably one of its preferred foods.
Commensals
Some gastropod mollusks are commensals with
E. gigas, mainly
CrepidulaCrepidula is a genus of sea snails, marine gastropod mollusks in the family Calyptraeidae, the slipper snails and cup-and-saucer snails....
spp.
The porcelain crab
Porcellana sayana is also known to be a commensal.
A small cardinal fish, known as the conch fish (
Apogon steallatus) , sometimes lives in the mantle of the conch for protection.
Parasites
The queen conch is very often parasited by protists of the phylum
ApicomplexaThe Apicomplexa are a large group of protists, most of which possess a unique organelle called apicoplast and an apical complex structure involved in penetrating a host's cell. They are unicellular, spore-forming, and exclusively parasites of animals. Motile structures such as flagella or...
, which are common parasites of molluscs. Those coccidian parasites initially allocate themselves in large
vacuolatedthumb|400px|Plant cell structurethumb|400px|Animal cell structureA vacuole is a membrane organelle which is present in all plant and fungal cells and some protist, animal and bacterial cells...
cell-Science and technology:*Cell , the basic organizational unit of all living organisms*Cell , a term used in electronic circuit design schematics*Cell , a three-dimensional element, part of a higher-dimensional object...
s of the
hostsIn biology, a host is an organism that harbors a parasite , or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...
digestive glandThe digestive system of gastropods has evolved to suit almost every kind of diet and feeding behavior. Gastropods as the largest taxonomic class of the mollusca are very diverse indeed: the group includes carnivores, herbivores, scavengers, filter feeders, and even parasites.In particular, the...
, where they reproduce freely. The infestation may proceed to the
secretorySecretion is the process of elaborating, releasing, and oozing chemicals from a cell, a secreted chemical substance or amount of substance. In contrast to excretion, the substance may have a certain function, rather than being a waste product....
cells of the same organ, and the entire life cycle of the parasite will likely occur within the same host and tissue.
Predators
Eustrombus gigas is prey to several species of carnivorous gastropod mollusks, such as:
- The apple murex, Chicoreus pomum
- The lamp shell, Xancus angulatus
- The moon snails Natica
Natica is a genus of predatory sea snails, marine gastropods in the family Naticidae, the moon snails.The genus is known from the Cretaceous to the recent periods.- Species :Species within the genus Natica include:...
spp. and PolinicesPolinices is a genus of sea snails, marine gastropod molluscs in the family Naticidae known as moon shells.-Species:Species within the genus Polinices include:* Polinices aperinus * Polinices bahamiensis ...
spp.
- The muricid
Muricidae, common names murex snails or rock snails, is a large and varied taxonomic family of small to large predatory sea snails...
snail Murex margaritensis
- The trumpet triton, Charonia variegata
- The tulip snail, Fasciolaria tulipa
Many
crustaceanCrustaceans are a very large group of arthropods, comprising almost 52,000 described species , and are usually treated as a subphylum . They include various familiar animals, such as crabs, lobsters, crayfish, shrimp, krill and barnacles...
s are also known pretadors of conchs, such as:
- The blue crab, Callinectes sapidus
- The box crab, Calappa gallus
- The giant hermit crab, Petrochirus diogenes
Petrochirus diogenes is a giant hermit crab of the marine hermit crab species which lives in the Caribbean, often inhabiting conch shells....
- The spiny lobster, Panulirus argus
Panulirus argus is a species of spiny lobster that lives on reefs and in mangrove swamps in the western Atlantic Ocean. Its common names include Caribbean spiny lobster, Florida spiny lobster or West Indies spiny lobster; the species is also referred to as lagostino, crawfish, crayfish or...
And several other species.
Eustrombus gigas is also prey to echinoderms, such as the cushion star,
Oreaster reticulatus, and many vertebrates, including
fishA fish is any aquatic vertebrate animal that is typically ectothermic , covered with scales, and equipped with two sets of paired fins and several unpaired fins...
, sea turtles and humans.
As food
Conch meat has traditionally been an important part of the diet in many islands in the West Indies. In the Spanish-speaking regions, for example in the
Dominican RepublicThe Dominican Republic is a nation on the island of Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are occupied by two countries...
,
Eustrombus gigas meat is known as
Lambí. Unsustainable conch fishery is the threat. There has been increasing concern about the conch fishery as populations have been depleted. Queen conch meat is used mainly for consumption but is also used as
fishing baitFishing bait is any substance used to attract and catch fish, e.g. on the end of a fishing hook.-History:Traditionally, nightcrawlers, insects, and smaller fish have been used for this purpose...
.
Eustrombus gigas is among the most important fishery resources in the
CaribbeanThe Caribbean is a region consisting of the Caribbean Sea, its islands , and the surrounding coasts...
and its harvest value was 30 million U.S. $ in 1992, and in 2003 was 60 million U.S. $.
The total annual harvest of meat of
Eustrombus gigas ranged from 6,519,711 kg to 7,369,314 kg between 1993 and 1998, and later its production declined to 3,131,599 kg in 2001. Data about imports of meat of
Eustrombus gigas into USA varies from 304,000 kg in 2007 to 1,832,000 kg in 1998.
As decorative objects and for jewelry
The shell is popular as a decorative object, but its export is now regulated and restricted by the CITES agreement.
Very rarely, a pink colored conch
pearlA pearl is a hard, generally spherical object produced within the soft tissue of a living shelled mollusk. Just like the shell of a mollusk, a pearl is made up of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and...
is found within the
mantleThe mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass....
of the animal. The most attractive of the conch
pearlA pearl is a hard, generally spherical object produced within the soft tissue of a living shelled mollusk. Just like the shell of a mollusk, a pearl is made up of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and...
s from this species have value as gemstones and have been used for necklaces and earrings. A conch pearl is a non-nacreous, natural calcareous concretion, which differs from most
pearlA pearl is a hard, generally spherical object produced within the soft tissue of a living shelled mollusk. Just like the shell of a mollusk, a pearl is made up of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and...
s sold as gemstones.
Historical human use
Classic
MayanThe Maya is a Mesoamerican civilization, noted for the only known fully developed written language of the pre-Columbian Americas, as well as its art, architecture, and mathematical and astronomical systems. Initially established during the Preclassic period , many Maya cities reached their highest...
art depicts what appears to be the shell of
Eustrombus gigas being worn on the hands of boxers.
The south Florida Indians (such as the
Tequestahi your butt is showing!The Tequesta Native American tribe, at the time of first European contact, occupied an area along the southeastern Atlantic coast of Florida...
) and
Carib IndiansCarib, Island Carib or Kalinago people, after whom the Caribbean Sea was named, live in the Lesser Antilles islands. They are an Amerindian people whose origins lie in the southern West Indies and the northern coast of South America....
used to make
knivesA knife is any cutting edge or blade, handheld or otherwise, with or without a handle. Knives were used at least two-and-a-half million years ago, as evidenced by the Oldowan tools. Originally made of rock, flint, and obsidian; knives have evolved in construction as technology has with blades...
, ax heads, and
chiselA chisel is a tool with a characteristically shaped cutting edge of blade on its end, for carving or cutting a hard material such as wood, stone, or metal...
s out of the lip of the conch before they acquired metal.
Threats and population biology
Eustrombus gigas abundance is declining throughout the species's range as a result of
overfishingOverfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....
and poaching. Populations of the species in
HondurasHonduras is a republic in Central America. It was formerly known as Spanish Honduras to differentiate it from British Honduras...
,
HaitiHaiti , officially the Republic of Haiti , is a Creole- and French-speaking Caribbean country. Along with the Dominican Republic, it occupies the island of Hispaniola, in the Greater Antillean archipelago...
, and the
Dominican RepublicThe Dominican Republic is a nation on the island of Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are occupied by two countries...
, in particular, are currently being exploited at rates that may be unsustainable. Trade from many Caribbean countries is known or suspected to be unsustainable, and illegal harvest, including fishing of the species in foreign waters and subsequent illegal international trade, is a common and widespread problem in the region.
Overfishing of this species is a now a very serious concern throughout most of its range. Only the adult conch is capable of reproduction. Unfortunately there is almost as much meat in a very large juvenile as there is in an adult, and so, wherever the adults have become rare, conch fisherman will instead harvest the larger juveniles before they have reached sexual maturity and had a chance to reproduce. Since these days the meat is taken out of the shell while the fisherman is still out at sea and the empty shells are dumped overboard, it is hard to enforce the rules that require a fisherman to take only adult conchs.
On many islands, despite local regulations to the contrary, immature conchs form the vast majority of the harvest. If this continues unabated, eventually the populations of this species will crash, and will very likely be unable to recover. The Caribbean "International Queen Conch Initiative" is an attempt at a fisheries management scheme for this species, and has its own website.
Conservation
This species is mentioned in CITES since 1985 and it is Appendix II since 1992, because of continuous population decline, so its trade is strictly regulated.
Queen conch are managed under national regulation. In the United States, all takes of queen conch are prohibited in Florida and adjacent Federal waters. No international regional fishery management organization exists in the Wider Caribbean. However, in Puerto Rico and the Virgin Islands, queen conch is regulated under the auspices of the Caribbean Fishery Management Council (CFMC).
In 1990, 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 II of its Protocol Concerning Specially Protected Areas and Wildlife (SPAW Protocol) as a species that may be used on a rational and sustainable basis and that requires protective measures. Because of this recognition, the United States proposed queen conch for listing in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) in 1992; this proposal was adopted, and queen conch became the first large-scale fisheries product to be regulated by CITES.
Since 1995, CITES has been reviewing the biological and trade status of queen conch under its Significant Trade Review process. Significant Trade Reviews are undertaken when there is concern about levels of trade in an Appendix II species. Based on the 2003 CITES review, CITES recommended that all countries prohibit the importation of queen conch from Honduras, Haiti, and the Dominican Republic (see
Standing Committee Recommendations from CITES). Queen conch continues to be available from many other Caribbean countries, including Jamaica and the Turks and Caicos Islands (British West Indies), which have well-managed queen conch fisheries.
External links