''Hexaplex trunculus'' (previously known as ''Murex trunculus'', ''Phyllonotus trunculus'', or the banded dye-murex) is a medium-sized

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

, a

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the family

Muricidae Muricidae is a large and varied taxonomic family of small to large predatory sea snails, marine gastropod mollusks, commonly known as murex snails or rock snails. With about 1,600 living species, the Muricidae represent almost 10% of the Neoga ...

, the

murex ''Murex'' is a genus of medium to large sized predatory tropical sea snails. These are carnivorous marine gastropod molluscs in the family Muricidae, commonly called "murexes" or "rock snails".Houart, R.; Gofas, S. (2010). Murex Linnaeus, 175 ...

shells or rock snails. It is included in the subgenus ''Trunculariopsis''. This species is a group of opportunist predatory snails that are known to attack their prey in groups. What is peculiar about this specific species is that they show no preference for the size of their prey, regardless of their hunger levels. The snail appears in fossil records dating between the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million year ...

periods (between 3.6 and 0.012 million years ago). Fossilized shells have been found in Morocco, Italy, and Spain.Fossilworks
/ref> This sea snail is historically important because its hypobranchial gland secretes a mucus used to create a distinctive purple-blue

indigo Indigo is a deep color close to the color wheel blue (a primary color in the RGB color space), as well as to some variants of ultramarine, based on the ancient dye of the same name. The word "indigo" comes from the Latin word ''indicum'', ...

dye A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution and ...

. Ancient

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on ...

cultures, including the Minoans,

Canaanites {{Cat main, Canaan See also: * :Ancient Israel and Judah Ancient Levant Hebrew Bible nations Ancient Lebanon 0050 Ancient Syria Wikipedia categories named after regions 0050 Phoenicia Amarna Age civilizations ...

Phoenicians Phoenicia () was an ancient thalassocratic civilization originating in the Levant region of the eastern Mediterranean, primarily located in modern Lebanon. The territory of the Phoenician city-states extended and shrank throughout their his ...

Hebrews The terms ''Hebrews'' (Hebrew: / , Modern: ' / ', Tiberian: ' / '; ISO 259-3: ' / ') and ''Hebrew people'' are mostly considered synonymous with the Semitic-speaking Israelites, especially in the pre-monarchic period when they were still ...

, and classical

Greeks The Greeks or Hellenes (; el, Έλληνες, ''Éllines'' ) are an ethnic group and nation indigenous to the Eastern Mediterranean and the Black Sea regions, namely Greece, Cyprus, Albania, Italy, Turkey, Egypt, and, to a lesser extent, ot ...

created dyes from the snails. One of the dye's main chemical ingredients is red dibromo-

indigotin Indigo dye is an organic compound with a distinctive blue color. Historically, indigo was a natural dye extracted from the leaves of some plants of the ''Indigofera'' genus, in particular '' Indigofera tinctoria''; dye-bearing ''Indigofera'' p ...

, the main component of

tyrian purple Tyrian purple ( grc, πορφύρα ''porphúra''; la, purpura), also known as Phoenician red, Phoenician purple, royal purple, imperial purple, or imperial dye, is a reddish-purple natural dye. The name Tyrian refers to Tyre, Lebanon. It is ...

tekhelet ''Tekhelet'' ( he, תְּכֵלֶת ''təḵēleṯ''; alternate spellings include ''tekheleth'', ''t'chelet'', ''techelet'' and ''techeiles'') is a "blue-violet", "blue", or "turquoise" dye highly prized by ancient Mediterranean civilizations. I ...

. 284 pp incl 192 figs. & 32 pls. The dye will turn indigo blue, similar to the color of blue jeans, if exposed to sunlight before the dye sets. ;Subspecies: * ''Hexaplex trunculus trunculus'' (Linnaeus, 1758)

Distribution

This species lives in the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on ...

and the

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

coasts of

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

and

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

, specifically

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = '' Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , ...

Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of th ...

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to A ...

, the

Canary Islands The Canary Islands (; es, :es:Canarias, Canarias, ), also known informally as the Canaries, are a Spanish Autonomous communities of Spain, autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to ...

Azores ) , motto =( en, "Rather die free than subjected in peace") , anthem= ( en, "Anthem of the Azores") , image_map=Locator_map_of_Azores_in_EU.svg , map_alt=Location of the Azores within the European Union , map_caption=Location of the Azores wi ...

. This murex occurs in shallow,

sublittoral The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal area ...

waters.

Shell description

''Hexaplex trunculus'' has a broadly conical shell about 4 to 10 cm long. It has a rather high spire with seven angulated

whorl 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 ...

s, and the shell is formed similar to the shape of a fish. The shell is variable in sculpture and coloring with dark banding, in four varieties. The ribs sometimes develop thickenings or spines and give the shell a rough appearance. The shell is often covered in algae, which camouflages it, making it appear very similar to the seabed. Mušle.jpg, Apertural view of a shell Mušle (2).jpg, Dorsal view of a shell Hexaplex Trunculus camouflaged in sea fouling.png, ''Hexaplex Trunculus'' camouflaged in

microalgae Microalgae or microphytes are microscopic algae invisible to the naked eye. They are phytoplankton typically found in freshwater and marine systems, living in both the water column and sediment. They are unicellular species which exist indiv ...

Muricidae - Hexaplex trunculus conglobatus.JPG, Fossil shell of ''Hexaplex trunculus conglobatus'' from Pliocene קונכיות ארגמונים מתקופת הברזל II (מאות 7-10 לפנה"ס).jpg, Murex shells from the Iron Age II period (10th-7th centuries BCE) with ancient remains of purple on the shards seen on the rights.

Human use

Snail secretions were used as

in ancient times. People still eat the snail in Spain and

As ancient dye

The purple dye originated in Phoenician colonies. The Phoenician port cities on the coast of current-day Lebanon, exported the dye across the Mediterranean. Tunisian Purple

The ancient method for mass-producing blue dye from ''Hexaplex trunculus'' has not been successfully reproduced; only today, with stronger, and therfore a less amount of reduction agents, which are more transparent, can we break the original purplish hue molecule and degraded by introducing it to UV sun rays, and as a result get a mere blue color, only. Therefore, archeologists have confirmed ''Hexaplex trunculus'' as the species used to create the purple-blue dye; large numbers of shells were recovered from inside ancient live-storage chambers that were used for harvesting. Apparently, 10- to 12,000 shells yielded only one gram of dye. Because of this, the dye was highly prized. Also known as ''Royal Purple'', it was prohibitively expensive and was only used by the highest ranking aristocracy. A similar dye, ''

Tyrian purple Tyrian purple ( grc, πορφύρα ''porphúra''; la, purpura), also known as Phoenician red, Phoenician purple, royal purple, imperial purple, or imperial dye, is a reddish-purple natural dye. The name Tyrian refers to Tyre, Lebanon. It is ...

'', which is purple-red in color, was made from a related species of marine snail, ''

Murex brandaris ''Bolinus brandaris'' (originally called ''Murex brandaris'' by Linnaeus and also Haustellum brandaris), and commonly known as the purple dye murex or the spiny dye-murex, is a species of medium-sized predatory sea snail, an edible marine gastrop ...

''. This dye (alternatively known as ''imperial purple'', see

purple Purple is any of a variety of colors with hue between red and blue. In the RGB color model used in computer and television screens, purples are produced by mixing red and blue light. In the RYB color model historically used by painters ...

) was also prohibitively expensive. Jews may have used the pigment from the shells to create a sky-blue, ''

'', dye to put on the fringes that the

Torah The Torah (; hbo, ''Tōrā'', "Instruction", "Teaching" or "Law") is the compilation of the first five books of the Hebrew Bible, namely the books of Genesis, Exodus, Leviticus, Numbers and Deuteronomy. In that sense, Torah means the ...

specifies for the corner of the prayer shawl. This blue dye would have been made by taking the yellow dye solution and letting it sit in the sunlight, and then dipping the wool in it. This dye was lost to history until it was rediscovered by Professor Otto Elsner of the Shenkar College of Fibers in

Haifa Haifa ( he, חֵיפָה ' ; ar, حَيْفَا ') is the third-largest city in Israel—after Jerusalem and Tel Aviv—with a population of in . The city of Haifa forms part of the Haifa metropolitan area, the third-most populous metropol ...

. Since then, it has been re-introduced as the authentic ''tekhelet'' and has once again been reinstated to the Jewish garment although only with limited acceptance.

References

* Ruppert, E.E., R.S. Fox and R.D. Barnes 2004 ''Invertebrate Zoology. A functional evolutionary approach''. 7th Ed. Brooks/Cole, Thomson Learning learning, Inc. 990 p. * Templado, J. and R. Villanueva 2010 ''Checklist of Phylum Mollusca.'' pp. 148-198 In Coll, M., et al., 2010. The biodiversity of the Mediterranean Sea: estimates, patterns, and threats. PLoS ONE 5(8):36pp * Settepassi F. (1970). Atlante malacologico dei molluschi marini viventi nel Mediterraneo Vol. 1. alacologial atlas of living marine molluscs in Mediterranean Sea, Vol. 1.Museo di Zoologia del Communedi.Roma * Coen G. (1933). Saggio di una Sylloge Molluscorum Adriaticorum. Memorie del Regio Comitato Talassografico Italiano 192: pp. i-vii, 1-186

External links

*
Linnaeus, C. (1758). Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima, reformata [10th revised edition
vol. 1: 824 pp. Laurentius Salvius: Holmiae.]
Danilo F. & Sandri G. B. (1856). Elenco nominale dei gasteropodi testacei marini raccolti nei dintorni di Zara. pp. 107-150, In: Programma dell'I.R. ginnasio completo di prima classe: in Zara alla fine dell'anno scolastico 1855-1856. Zara, Tipografia Governiale.

Risso, A. (1826-1827). Histoire naturelle des principales productions de l'Europe Méridionale et particulièrement de celles des environs de Nice et des Alpes Maritimes. Paris, Levrault:. . 3(XVI): 1-480, 14 pls.

Lamarck,_[J.-B._M.
de._(1822)._Histoire_naturelle_des_animaux_sans_vertèbres._Tome_septième._Paris:_published_by_the_Author,_711_pp.html" ;"title=".-B. M.">Lamarck, [J.-B. M.
de. (1822). Histoire naturelle des animaux sans vertèbres. Tome septième. Paris: published by the Author, 711 pp">.-B. M.">Lamarck, [J.-B. M.
de. (1822). Histoire naturelle des animaux sans vertèbres. Tome septième. Paris: published by the Author, 711 pp
Gregorio A. de. (1884-1885). Studi su talune conchiglie mediterranee viventi e fossili con una rivista del genere Vulsella. Bullettino della Società Malacologica Italiana. 10: 36-128 [1884
129-288 [1885], pl. 1-5]
Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca. in: Costello, M.J. et al. (eds), European Register of Marine Species: a check-list of the marine species in Europe and a bibliography of guides to their identification. Patrimoines Naturels. 50: 180-213
{{Commonscat Muricidae