page_title: Tyrian purple
section_title: Production from sea snails
hierarchical_section_title: Tyrian purple / Production from sea snails
caption_attribution_description: Haustellum brandaris, loc. Torregaveta, Bacoli (NA) Italy
context_page_description: Tyrian purple, 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 a secretion produced by several species of predatory sea snails in the family Muricidae, rock snails originally known by the name 'Murex'. In ancient times, extracting this dye involved tens of thousands of snails and substantial labor, and as a result, the dye was highly valued. The main chemical is '6,6′-dibromoindigo.
context_section_description: The dye substance is a mucous secretion from the hypobranchial gland of one of several species of medium-sized predatory sea snails that are found in the eastern Mediterranean Sea. These are the marine gastropods Bolinus brandaris the spiny dye-murex (originally known as Murex brandaris Linnaeus, 1758), the banded dye-murex Hexaplex trunculus, the rock-shell Stramonita haemastoma, and less commonly a number of other species such as Bolinus cornutus. The dye is an organic compound of bromine (i.e., an organobromine compound), a class of compounds often found in algae and in some other sea life, but much more rarely found in the biology of land animals.
  In nature the snails use the secretion as part of their predatory behaviour in order to sedate prey and as an antimicrobial lining on egg masses. The snail also secretes this substance when it is attacked by predators, or physically antagonized by humans (e.g., poked). Therefore, the dye can be collected either by "milking" the snails, which is more labour-intensive but is a renewable resource, or by collecting and destructively crushing the snails. David Jacoby remarks that "twelve thousand snails of Murex brandaris yield no more than 1.4 g of pure dye, enough to colour only the trim of a single garment."
  Many other species worldwide within the family Muricidae, for example Plicopurpura pansa, from the tropical eastern Pacific, and Plicopurpura patula from the Caribbean zone of the western Atlantic, can also produce a similar substance (which turns into an enduring purple dye when exposed to sunlight) and this ability has sometimes also been historically exploited by local inhabitants in the areas where these snails occur. (Some other predatory gastropods, such as some wentletraps in the family Epitoniidae, seem to also produce a similar substance, although this has not been studied or exploited commercially.) The dog whelk Nucella lapillus, from the North Atlantic, can also be used to produce red-purple and violet dyes.
caption: Two shells of Bolinus brandaris, the spiny dye-murex, a source of the dye
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