Lobatus gigas, originally known as Strombus gigas, commonly known as queen snail , is a species a large edible sea slug, sea mollusc gastropod in a true shell family, Strombidae. This species is one of the largest mollusks from the northwest Atlantic tropics, from Bermuda to Brazil, reaching up to 35.2 centimeters (13.9 inches) in shell length. L. gigas is closely related to the Goliath conch, Lobatus Goliath , endemic species in Brazil, and also the Chicken Conch, Lobatus gallus .
Conch queens are herbivores and live on seagrass beds, although the habitat certainly varies according to the stage of development. Adult animals have a very large, heavy and heavy shell, with spiky bumps on the shoulders, thick, blazing outer lips, and distinctive pink openings. The lit lips do not exist on the younger specimens. The external anatomy of the soft parts of L. gigas is similar to that of other snails in the family; it has a long muzzle, two eyestalks with well-developed eyes, additional sense tentacles, strong legs and a crescent-shaped, corneum-shaped operculum.
The shells and soft parts of living L. gigas function as home to several commensal animals, including snail slugs, porcelain crabs and cardinals. The parasites include coccidians. The queen conch is hunted and eaten by several species of large predatory sea snails, as well as by starfish, crustaceans and vertebrates (fish, sea turtles and humans). The shell is sold as a souvenir and is used as a decorative object. Historically, Native Americans and indigenous Caribbean people used fragments of shells to create tools.
International trade in the Caribbean Queen's conch is regulated under the International Trade Convention on Endangered Fauna and Flora Agreement (CITES), which is listed as Strombus gigas . This species is not endangered in the Caribbean as a whole, but is commercially threatened in many areas, largely due to overfishing.
Video Lobatus gigas
Taxonomy and etymology
History
The queen's conch was originally described from the shell in 1758 by the Swedish naturalist and taxonomist Carl Linnaeus, who started the binomial nomenclature system. Linnaeus named the species Strombus gigas , which has remained a name received for over 200 years. Linnaeus made no mention of the specific location for this species, giving only "America" ​​as a type of locality. The specific name is the ancient Greek word gigas (? ???? ), meaning "giant", refers to the large size of this slug compared to almost all other gastropod mollusks. Strombus lucifer , which is considered a later synonym, is also described by Linnaeus in Systema Naturae .
In the first half of the 20th century, the type of material for the species was thought to be lost; in other words, the shell where Linnaeus bases its original description and which is likely to exist in its own collection, seems to be lost, which creates a problem for the taxonomist. To counter this, in 1941 a neotype of this species was appointed by American malacologists William J. Clench and R. Tucker Abbott. In this case, neotype is not the shell or all of the actual specimens, but a figure of a 1684 book
The taxonomy of Strombidae was extensively revised in the 2000s and several subgenera, including Eustrombus , rose to the genus level by some authors. Petuch and Petuch and Roberts combine this species as Eiggibus gustas, and Landau and collaborators (2008) incorporate them as Lobatus gigas .
Phylogeny
The phylogenetic relationship between Strombidae was mainly studied by Simone (2005) and Latiolais (2006), using two different methods. Simone proposed a cladogram (tree of descent) based on extensive morpho-anatomical analysis of Aporrhaidae, Strombidae, Xenophoridae and Struthiolariidae representatives, which include L. gigas (referred to as Eustrombus gigas ).
With the exception of Lambis and Terebellum , the remaining taxa is allocated in the genus Strombus , including L.Ã, my gigas Strombus gracilior , Strombus tools and Strombus pugilis , species species, remain inside Strombus , because they are a different group based on at least five synapomorphies (traits shared by two or more taxa and their most recent ancestors). The remaining taxis are considered subgenera and raised to the genus level by Simone. The genus Eustrombus (now considered a synonym of Lobatus), in this case, includes Eustrombus gigas (now considered a synonym of lobatus gigas ) and Eustrombus goliath (= lobatus goliath ), which are considered closely related.
In a different approach, Latiolais and colleagues (2006) proposed another cladogram that attempted to demonstrate the phylogenetic relationship of 34 species in the Strombidae family. The authors analyzed 31 species of Strombus, including Lobatus gigas (referred to as Strombus gigas), and three species in the allied genus Lambis i>. This cladogram is based on the DNA sequence of both histone H3 and cytochrome-c oxidase (COI) cytochrome protein-coding gene region. In this proposed phylogeny, Strombus gigas and Strombus gallus (Lobatus gallus) are closely related and seem to have a common ancestor.
Common names
Common names include "queen snails" and "pink conch" in English, caracol rosa and > caracol rosado in mexico, caracol de pala , cobo , botuto and guarura in Venezuela, caracol reina , lambÃÆ' in Dominican Republic and Grenada, and carrucho in Puerto Rico.
Maps Lobatus gigas
Anatomy
Shell
The adult shell usually has a length of 15-31 cm (5.9-12.2 inches), while the reported maximum size is 35.2 cm (13.9 inches). The skin is very dense and heavy, with 9 to 11 circles and outer lips that dilate and thicken. Although this notch does not develop as well as elsewhere in the family, the shell features are still seen in dextral (normal right-handed) adult specimens, as the secondary anterior curve of the lips, to the right of the siphonal canal (seen ventralally). Eyestalk left the beast protruding along this notch.
Spire is a protruding part of the shell that encompasses all whorls except the largest and last whorl (known as the whorl of the body). This is usually more elongated than in other strombide slugs, such as the closely-linked and larger goliath throat, Lobatus goliath that is endemic in Brazil. In L.Ã, gigas , glossy or glaze layers around the adult shell holes are especially pale pink. This may indicate the color of beige, peach or yellow, but sometimes also colored with deep magenta, the shadow is almost red. The periostracum, the protein layer (conchiolin) which is the outermost part of the skin surface, thin and pale brown or brown.
The overall shell morphology of L. gigas is not only determined by animal genes; environmental conditions such as location, diet, temperature and depth, and biological interactions such as predation, can greatly affect that. Snail teens develop a heavier shell when exposed to predators. Conches also developed a wider and thicker shell with fewer spines but longer in deeper water.
Teen shells shells are very different in appearance from adults. Clearly visible is the absence of a burning outer lips; juvenile shells have simple sharp lips, which provide conical or bikonic shells. In Florida, adolescent queen shells are known as "rollers", because the motion of waves is so easy to overthrow its shells, while it is almost impossible to overthrow an adult specimen, because of its shell weight and asymmetric profile. Subadult shells have thin lips that continue to grow thick to death.
The shell's shell is about 95% calcium carbonate and 5% organic matter.
Historical illustration
The index testarum conchyliorum (published in 1742 by Italian physician and psychiatrist NiccolÃÆ'² Gualtieri) contains three adult skin illustrations of various perspective. The protruding tops of the towers and the glowing outer lips, with wing-like contours extending out of the last circle, are a striking feature of these images. The shell is shown as balancing at the edges of the lips and/or tops; this may be done for artistic reasons because this shell can not balance like this.
One of the most valuable shell publications of the 19th century, a series of books titled Illustrations conchyliologiques ou descriptions and figures de toutes les coquilles connues, vivantes et fossiles (published by French naturalist Jean-Charles Chenu from 1842 to 1853), contains illustrations of adult and juvenile shells L.Ã, gigas and one colorless image describes some soft parts of animals. Nearly forty years later, colorful illustrations of the Manual of Conchology (published in 1885 by the Americanologist George Washington Tryon) show the back view of the shell of a small teenager with a distinctive brown and white pattern.
Soft section
Many details about the anatomy of Lobatus gigas were not known until Colin Little's 1965 general study. In 2005, R. L. Simone gave a detailed description of anatomy. L. gigas has a long snout with two eyestalks (also known as ommatophores) derived from the base. The tip of each eyestalk contains large eyes, well-developed eyes, with black pupils and yellow iris and a small posterior little sensory tentacle. Eyes Amputation fully regenerates. In the animal's mouth is a radula (a ribbon that is difficult to cover by microscopic rows of teeth) of a taenioglossan type. Both snout and eyestalks show dark patches in the open area. The dark-colored coat in the anterior area, fades into a light gray at the posterior back, while the coat collar is generally orange in color. Siphon is also orange or yellow. When the soft part of the animal is removed from the shell, some organs can be distinguished externally, including the kidneys, the nephyridial glands, the pericardium, the genital glands, the stomach, the gastric sac and the gastrointestinal gland. In adult men, the penis is also visible.
Foot/locomotion
The species has large and strong legs with brown spots and markings toward the edges, but the white is closer to the visceral hump that remains inside the shell and accommodates internal organs. The base of the anterior end of the foot has a different 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 a dark brown, corneous, crescent-shaped operculum, which is reinforced by a different center rib. The base of the two thirds of the back of the animal's leg is rounded; only an anterior third touches the ground as it moves. Columella, the central pillar within the shell, serves as an attachment point for white columellar muscle. This strong muscle contraction allows the soft parts of animals to shelter in the shell in response to unwanted stimuli.
Lobatus gigas has an unusual propulsion, first described in 1922 by George Howard Parker (1864-1955). The first animal fixes the posterior end of the foot by pushing the sickle-shaped operculum point into the substrate, then extending the legs forward, lifting and throwing the shell forward in a so-called jump motion. This move is thought to resemble a pole dome, making a good climber even from a vertical concrete surface. This jump motion can help prevent predators from following the snail's chemical trail, which otherwise would leave a continuous trail on the substrate.
Life cycle
Lobatus gigas is gonocoristic, meaning each slug is male or female. Women are usually larger than males in natural populations, with both sexes present in the same proportion. After internal fertilization, females lay eggs in gelatinous strings, which can be as long as 75 feet (23 m). It is layered in sand patches or seagrass beds. The sticky surfaces of these long egg strings allow them to roll and coagulate, mixing with the sand around them to form a compact egg mass, a shape determined by the anterior portion of the outer lips of the female shell as they are plated. Each of the egg mass may have been fertilized by many men. The number of eggs per egg varies greatly depending on environmental conditions such as food availability and temperature. Generally, females produce 8-9 egg masses per season, each containing 180,000-460,000 eggs, but the amount can be as high as 750,000 eggs. Women can spawn several times during the reproductive season, which runs from March to October, with peak activity occurring from July to September.
Embryo of the conch queen hatch 3-5 days after spawning. At the time of hatching, protoconch (translucent embryonic) is translucent and has a white background color, beige with a small pustulate mark. This color is different from other Caribbean Lobatus, such as Lobatus raninus and Lobatus costatus, which have non-pigmented embryo shells. After that, two veliger lobes appear (common larvae form for various gastropods of sea water and fresh water and bivalves mollusks) spend several days developing in plankton, eating mainly on phytoplankton. Metamorphosis occurs about 16-40 days of hatching, when protokonch grows completely about 1.2 mm. After metamorphosis, individuals spend the rest of their lives in the benthic zone (on or on the surface of the sediment), usually remain buried during the first year of life. Conch queens reach sexual maturity in about 3 to 4 years, reaching a shell length of nearly 180 mm and weighing up to 5 kilograms. Individuals can usually live up to 7 years, although in deeper waters they can reach 20-30 years and a maximum life expectancy of 40 years. It is believed that mortality rates tend to be lower in mature shells due to their thickened shells, but can be much higher for juveniles. Estimates have shown that mortality rates decreased with increasing size and may also vary due to habitat, season and other factors.
Ecology
Distribution
Lobatus gigas is a native of the West Atlantic tropical beaches in North and Central America in the larger tropical Caribbean zone. Although the species undoubtedly occur elsewhere, this species has been recorded in scientific literature as it did, in: Aruba, (Netherlands Antilles); Barbados; Bahamas; Belize; Bermuda; The northern and northeastern regions of Brazil (though this is contested); Old Providence Island in Colombia; Costa Rica; Dominican Republic; Panama; Swan Islands in Honduras; Jamaica; Martinique; Alacran Reef, Campeche, Cayos Arcas and Quintana Roo, in Mexico; Puerto Rico; Saint BarthÃÆ' © lemy; Mustique and Grenada in the Grenadines; Pinar del RÃÆ'o, Northern Havana Province, North Matanzas, Villa Clara, Cienfuegos, HolguÃÆ'n, Santiago de Cuba and Guantánamo, in Turks and Caicos Islands and Cuba; South Carolina, Florida, with Florida Keys and Flower Garden Banks National Marine Sanctuary, in the United States; Carabobo, Falcon, Gulf of Venezuela, the islands of Los Roques, Los Testigos Islands, and Sucre in Venezuela; St. Croix in the Virgin Islands.
Habitat
Lobatus gigas lives in depth from 0.3-18 m to 25-35 m. The distance is limited by the distribution of seagrass and algae cover. In a highly exploited area, the queen's queen is more abundant in the deepest range. The queen conch lives in seagrass beds and on sandy substrates, usually in conjunction with turtle grass (species of genus Thalassia <, i especially Thalassia testudinum and also Syringodium i> sp.) and manatee grass ( Cymodocea sp.). Teenagers inhabit a shallow seagrass grass on the beach, while adults prefer algae plains and grassy meadows. Critical nursery habitat for adolescent individuals is defined by a series of characteristics, including tidal circulation and macroalgae production, which together allow for high rates of recruitment and survival. L. gigas are usually found in different aggregates that may contain several thousand individuals.
Diet
Strombid Gastropods are widely accepted as carnivores by some writers in the 19th century, a concept that survived until the first half of the 20th century. This false idea comes from the writings of Jean-Baptiste Lamarck, who classifies strombides with other supposedly carnivorous snails. This idea is then repeated by other authors, but is not supported by observation. Future research has disproved the concept, proving beyond a doubt that strombid gastropods are herbivorous animals. Similar to other Strombidae, Lobatus gigas is a special herbivore, which feeds on macroalgae (including red algae, such as species Gracilaria and Hypnea ), seagrass and algae unicellular, intermittently also eating algal detritus. Green macroalga Batophora oerstedii is one of the preferred foods.
Interactions
Some different animals construct commensal interactions with L. gigas , which means that the two organisms maintain a favorable (commensal) relationship of the species but not the other (in this case, the queen of snails). Commensals of this species include certain molluscs, especially sandal shells ( Crepidula spp.) Porcelain crabs Porcellana chines also known as commensal and small cardinalfish, known as fish snails ( Astrapogon stellatus ), sometimes a shelter in the conch's mantle for protection. L. gigas is very often parasitic by protists from Apicomplexa phyla, which is a common mollusk parasite. The coccidian parasite, which is a single celled microorganism, forms spores, initially forming itself in large vacuole cells from the host's gastrointestinal glands, where they reproduce freely. The infestation may progress to the secretory cells of the same organ. The entire life cycle of the parasite usually occurs in one parent and tissue.
Lobatus gigas are prey species for some carnivorous gastropods, including murex apples
Usage
Conch meat has been consumed for centuries and has traditionally been an important part of dieting on many islands in the West Indies and South Florida. It is consumed raw, salted, minced or chopped in a variety of dishes, such as salad, chowder, fried, soup, stew, pÃÆ'Â ¢ tÃÆ'Ã… © s and other local recipes. In both the English-speaking and Spanish-speaking regions, for example in the Dominican Republic, Lobatus gigas meat is known as lambÃÆ' i>. Although conch meat is used primarily for human consumption, it is sometimes used as a fishing lure (usually a leg). L. gigas is one of the most important fisheries resources in the Caribbean: its harvest value is US $ 30 million in 1992, increasing to $ 60 million in 2003. Total annual meat yields L.Ã, gigas ranged from 6,519,711 kg to 7,369,314 kg between 1993 and 1998, production subsequently decreased to 3,131,599 kg in 2001. Data on US imports showed a total of 1,832,000 kg in 1998, compared with 387,000 kg in 2009, a decline of almost 80% twelve years later.
Queen conch shells are used by Native Americans and Caribbean Indians in various ways. South Florida bands (such as Tequesta), Karib, Arawak and TaÃÆ'no use conch shells to make tools (such as knives, ax heads and chisels), jewelry, cookware and use it as a horn blowing. In Mesoamerican history, Aztecs use shells as part of a mosaic of jewelry like a two-headed snake. The Aztecs also believe that the sound of a trumpet made from the queen of conch shells represents the divine manifestation, and uses it in religious ceremonies. In central Mexico, during a rainy ceremony dedicated to Tlaloc, the Mayans used conch shells as hand protector (in a way similar to boxing gloves) during the battle. The ancient Midden of the Ligang gigas perforated hollow shell is considered evidence that the pre-Columbian Lucayan Indians in the Bahamas use the queen of snails as a source of food.
Brought by explorers, the conch shell queen quickly became a popular asset in early modern Europe. At the end of the 17th century they were widely used as a decoration over the mantels of fireplaces and English gardens, among other places. In contemporary times, conch shells are mainly used in handicrafts. The shells are made into cameos, bracelets and lamps, and traditionally as doorstops or decorations by the male sailors' families. Shell continues to be popular as a decorative object, although its exports are now regulated and limited by the CITES agreement. In modern culture, the queen of conch shells is often represented in everyday objects such as coins and stamps.
Very rarely (about 1 in 10,000 snails), a pearl snail can be found inside the mantle. Although they occur in a variety of colors that match the shell interior color, the pink specimens are the most valuable. This pearl is considered semi-glorious, and kurio is a popular tourist. The best specimens have been used to make necklaces and earrings. The pearl conch is a non-nacreous pearl (previously referred to by some sources as 'calcareous concretion') which is different from most pearls sold as gems.
Research into the unique architecture of conch shells is currently underway at MIT.
Status
Threat
In shellfish fisheries, one of the threats to sustainability stems from the fact that there is almost as much meat in adolescents as large as there are in adults, but only mature snails can reproduce, and thus retain population. In many places where adult snails have become scarce due to overfishing, older teenagers and sub-adult are taken before they mate. In some islands, a small part of the crop. Lobatus gigas abundance decreases throughout its reach as a result of overfishing and hunting. Trade from many Caribbean countries such as Antigua and Barbuda, Honduras, Haiti and the Dominican Republic are known or deemed unsustainable. In 2001, the queen's snail population in at least 15 Caribbean countries and states was overwhelmed and/or overexploited. Illegal logging, including fishing in foreign waters and illegal international trade, is a common problem in the region. The Caribbean "International Queen Conch Initiative" is an international effort to manage this species.
Currently, the biggest threat to the queen of snails is ocean acidification. The level of acidity increases and has a bad effect on the shell larvae. As we continue to release more CO 2 into the atmosphere, these will be captured by the oceans, eventually they will become increasingly corrosive and the organisms that have shells and calcium carbonate structures will become negatively affected. The particular larval stage of the shell is very sensitive to low pH. Shellfish are heavily dependent on calcium carbonate but with an increase in pH because this carbonic acid will have a negative impact on all marine life, not just snails.
Preservation
The snail queen fishery is usually managed under individual state regulations. In the United States all the snail queen taking is banned in Florida and in adjacent federal waters. There is no international regional fisheries management organization available for the entire Caribbean region, but in places like Puerto Rico and the Virgin Islands, the queen of snails is organized under the auspices of the Caribbean Fisheries Management Board (CFMC). In 2014, Parties to the Convention for the Protection and Development of Marine Environment in the Greater Caribbean Region (the Cartagena Convention) include the snail queen in the Annex III Protocol on Special Protected Areas and Wildlife (SPAW Protocol). Species included in Annex III require specific measures to be taken to ensure their protection and restoration, and their use is permitted and properly regulated.
This species has been mentioned in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) since 1985. In 1992 the United States proposed the quail to be included in Appendix II CITES, making the queen of snails in the first large-scale fishery product. is governed by CITES (such as Strombus gigas ). In 1995, CITES began reviewing the biological and trade status of the quail under the "Significant Trade Review" process. This review was conducted to address concerns about the level of trade in Appendix II species. Based on the 2003 review, CITES recommends that all countries ban imports from Honduras, Haiti and the Dominican Republic, according to the Recommendations of the Standing Committee. The quail meat continues to be available from other Caribbean countries, including Jamaica and Turks and Caicos, which operate a well-run quail snail fishery. For conservation reasons, the Colombian Government is currently banning the commercialization and consumption of snails between June and October.
The Bahamas National Trust builds awareness by educating teachers and students through workshops.
References
Further reading
- Coomans H.E. (1965). "Framework and shell objects from an Indian site on Magueyes Island, Puerto Rico". Caribbean Science Journal 5 (1-2): 15-23. PDF.
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Spade, D.J.; Griffitt, R.J.; Liu, L.; Brown-Peterson, N.J.; Kroll, K.J.; et al. (2010). "Queen Conch ( Strombus gigas ) Testis Regresses during Reproductive Season at Nearshore Sites in Florida Keys". PLoS ONE . 5 (9): e12737. doi: 10.1371/journal.pone.0012737. PMCÃ, 2939879 . PMID 20856805. - Stoner, A.W.; Waite, J.M. (1991). "Trophic biology of Strombus gigas in nursery habitats: diet and food sources in seagrass beds". Molluscan Study Journal . 57 (4): 451-460. doi: 10.1093/mollus/57.4.451.
External links
- "Queen Conch Factsheet". Waitt Institute . Retrieved 2015-06-08 .
- ARKive - pictures and movies of queen snail (Strombus gigas)
- The Web of Animal Diversity: Strombus gigas
- Microdocs: Life cycle Conch
- Bermuda Conservation Service Department (including Queen Conch Recovery Plan)
Source of the article : Wikipedia
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