''Conus geographus'', popularly called the geography cone or the geographer cone, 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 ...

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 ...

cone snail A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines con ...

. It lives in reefs of the tropical Indo-Pacific, and hunts small fish. While all cone snails hunt and kill prey using

venom Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a st ...

, the venom of conus geographus is potent enough to kill humans.WoRMS (2010). Conus geographus Linnaeus, 1758. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=215499 on 2011-07-24 The variety ''Conus geographus'' var. ''rosea'' G. B. Sowerby I, 1833 is a synonym of '' Conus eldredi'' Morrison, 1955. This species is the type species of : * ''Gastridium'' Modeer, 1793 * ''Rollus'' Montfort, 1810 * ''Utriculus'' Schumacher, 1817

Shell description

''C. geographus'' has a broad, thin shell, cylindrically inflated. Geography cones grow to about in length. The size of an adult shell varies between . The ground color of the shell is pink or violaceous white, occasionally reddish. It has a mottled appearance, clouded and coarsely reticulated with chestnut or chocolate, usually forming two very irregular bands. This intricate brown-and-white pattern is highly prized by shell collectors. The geography cone has a wide, violaceous white or pink

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 ...

and numerous shoulder ridges or spines. The shell is covered with thread-like revolving striae, usually nearly obsolete except at the base. The flattened

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 striated and coronated. In comparison with other species, the shell has a noticeably wider and convex mid-body, with a flattened

. Its walls are also noticeably thinner and lighter compared to other cone shells of similar length and size. File:Cone géographique.png, Apertural view File:Conusgeographus2.jpg, Abapertural view File:Cone géographiqueFace.png, Apical view

Distribution

Geography cones are common. They occur in the

Red Sea The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; ...

, in the Indian Ocean off

Chagos The Chagos Archipelago () or Chagos Islands (formerly the Bassas de Chagas, and later the Oil Islands) is a group of seven atolls comprising more than 60 islands in the Indian Ocean about 500 kilometres (310 mi) south of the Maldives arc ...

, Réunion,

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

Mauritius Mauritius ( ; french: Maurice, link=no ; mfe, label= Mauritian Creole, Moris ), officially the Republic of Mauritius, is an island nation in the Indian Ocean about off the southeast coast of the African continent, east of Madagascar. It ...

Mozambique Mozambique (), officially the Republic of Mozambique ( pt, Moçambique or , ; ny, Mozambiki; sw, Msumbiji; ts, Muzambhiki), is a country located in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi ...

and

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...

. They are indigenous to the reefs of the Indo-Pacific region, except for Hawaii, and off Australia (the

Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an Australian territory in the central and central northern regions of Australia. The Northern Territory shares its borders with Western Aust ...

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , establishe ...

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

Ecology

''C. geographus'' is a

piscivore A piscivore () is a carnivorous animal that eats primarily fish. The name ''piscivore'' is derived . Piscivore is equivalent to the Greek-derived word ichthyophage, both of which mean "fish eater". Fish were the diet of early tetrapod evoluti ...

that dwells in sediment of shallow

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

s, preying on small fish. It releases a venomous cocktail into the water in order to stun its prey. Like the other

s, it fires a harpoon-like, venom-tipped modified tooth into its prey; the harpoon is attached to the body by a

proboscis A proboscis () is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elong ...

, and the prey is pulled inside for ingestion.

Venom

The geography cone snail is highly dangerous; live specimens should be handled with extreme caution. ''C. geographus'' has the most toxic sting known among ''Conus'' species and there are reports for about three dozen human fatalities in 300 years. The venom has an

LD50 In toxicology, the median lethal dose, LD50 (abbreviation for "lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a toxic unit that measures the lethal dose of a toxin, radiation, or pathogen. The value of LD50 for a substance is the ...

toxicity in of 0.012-0.030 mg/kg.Conus geographus Linnaeus 1758
penelope.uchicago.edu The venom of the geography cone snail is a complex mix of hundreds of different toxins that is delivered through toxoglossan radula, a

harpoon A harpoon is a long spear-like instrument and tool used in fishing, whaling, sealing, and other marine hunting to catch and injure large fish or marine mammals such as seals and whales. It accomplishes this task by impaling the target animal ...

-like tooth propelled from an extendable

. There is no

antivenom Antivenom, also known as antivenin, venom antiserum, and antivenom immunoglobulin, is a specific treatment for envenomation. It is composed of antibodies and used to treat certain venomous bites and stings. Antivenoms are recommended only if th ...

for a cone snail sting, and treatment consists of keeping victims alive until the toxins wear off. The geography cone is also known colloquially as the "cigarette snail", a

gallows humor Black comedy, also known as dark comedy, morbid humor, or gallows humor, is a style of comedy that makes light of subject matter that is generally considered taboo, particularly subjects that are normally considered serious or painful to discus ...

exaggeration implying that, when stung by this creature, the victim will have only enough time to smoke a cigarette before dying. In reality, even the most venomous cone snails take about one to five hours to kill a healthy human, though medical care must still be prompt as, without it, death is almost certain. Among the compounds found in cone snail venom are proteins which, when isolated, have great potential as pain-killing drugs. Research shows that certain component proteins of the venom target specific human pain receptors and can be up to 10,000 times more potent than morphine without morphine's addictive properties and side-effects. Conantokin-G is a toxin derived from the

of ''C. geographus''. Only 15-20 of the venom's 100-200 toxic peptides are used for feeding. It is believed that the other compounds are defensive, and that the venom is mainly used for defense.

Insulin

Recent research has revealed that ''C. geographus'' uses a form of insulin as a means of stunning its prey. This insulin is distinct from its own (with shorter chains) and appears to be a stripped down version of those insulins found in fish. Once this venom passes through a fish's gills, the fish experiences hypoglycaemic shock, essentially stunning it and allowing for ingestion by the snail. This poison mixture has been referred to as ''nirvana cabal''. Along with the tulip cone snail '' C. tulipa'', no other species of any known lifeform is known to have used its own biological insulin as a weapon.

References

This article incorporates CC-BY-3.0 text from the reference.

Linnaeus, C. (1758). Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima, reformata. Laurentius Salvius: Holmiae. ii, 824 pp
* Dufo, M.H. 1840. ''Observations sur les Mollusques marins, terrestres et fluviatiles des iles Séchelles et des Amirantes''. Annales des Sciences Naturelles, Paris 2 14, Zoologie: 45-80 (extrait), 166-221(suite) * Reeve, L.A. 1843. ''Monograph of the genus Conus''. pls 1-39 in Reeve, L.A. (ed.). Conchologica Iconica. London : L. Reeve & Co. Vol. 1. * Hedley, C. 1899. ''The Mollusca of Funafuti. Part 1. Gastropoda.'' Memoirs of the Australian Museum 3(7): 395-488, 49 text figs * Schepman, M.M. 1913. ''Toxoglossa.'' 384-396 in Weber, M. & de Beaufort, L.F. (eds). The Prosobranchia, Pulmonata and Opisthobranchia Tectibranchiata, Tribe Bullomorpha, of the Siboga Expedition. Monograph 49. Siboga Expeditie 32(2) * Allan, J.K. 1950. ''Australian Shells: with related animals living in the sea, in freshwater and on the land''. Melbourne : Georgian House xix, 470 pp., 45 pls, 112 text figs. * Satyamurti, S.T. 1952. ''Mollusca of Krusadai Is. I. Amphineura and Gastropoda''. Bulletin of the Madras Government Museum, Natural History ns 1(no. 2, pt 6): 267 pp., 34 pls * Gillett, K. & McNeill, F. 1959. ''The Great Barrier Reef and Adjacent Isles: a comprehensive survey for visitor, naturalist and photographer''. Sydney : Coral Press 209 pp. * McMichael, D.F. 1960. ''Shells of the Australian Sea-Shore''. Brisbane : Jacaranda Press 127 pp., 287 figs. * Rippingale, O.H. & McMichael, D.F. 1961. ''Queensland and Great Barrier Reef Shells''. Brisbane : Jacaranda Press 210 pp. * Wilson, B.R. & Gillett, K. 1971. ''Australian Shells: illustrating and describing 600 species of marine gastropods found in Australian waters''. Sydney : Reed Books 168 pp. * Hinton, A. 1972. ''Shells of New Guinea and the Central Indo-Pacific''. Milton : Jacaranda Press xviii 94 pp. * Salvat, B. & Rives, C. 1975. ''Coquillages de Polynésie.'' Tahiti : Papéete Les editions du pacifique, pp. 1–391. * Cernohorsky, W.O. 1978. ''Tropical Pacific Marine Shells.'' Sydney : Pacific Publications 352 pp., 68 pls. * Wilson, B. 1994. ''Australian Marine Shells. Prosobranch Gastropods''. Kallaroo, WA : Odyssey Publishing Vol. 2 370 pp. * Röckel, D., Korn, W. & Kohn, A.J. 1995. ''Manual of the Living Conidae. Volume 1: Indo-Pacific Region''. Wiesbaden : Hemmen 517 pp. * Filmer R.M. (2001). ''A Catalogue of Nomenclature and Taxonomy in the Living Conidae 1758 - 1998''. Backhuys Publishers, Leiden. 388pp * Tucker J.K. (2009). ''Recent cone species database''. September 4, 2009 Edition * Tucker J.K. & Tenorio M.J. (2009) ''Systematic classification of Recent and fossil conoidean gastropods''. Hackenheim: Conchbooks. 296 pp
Puillandre N., Duda T.F., Meyer C., Olivera B.M. & Bouchet P. (2015). ''One, four or 100 genera? A new classification of the cone snails.'' Journal of Molluscan Studies. 81: 1-23

Gallery

File:Conus geographus 1.jpg, ''Conus geographus'' Linnaeus, C., 1758 File:Conus geographus 2.jpg, ''Conus geographus'' Linnaeus, C., 1758 File:Conus geographus 3.jpg, ''Conus geographus'' Linnaeus, C., 1758 File:Conus geographus 4.jpg, ''Conus geographus'' Linnaeus, C., 1758

External links

by James Grout. *
Cone Shells - Knights of the Sea
* {{DEFAULTSORT:Conus Geographus geographus Gastropods described in 1758 Taxa named by Carl Linnaeus