![]() (“Mr & Mrs Sepia, Cuttlefish Kingpins of Nebraska” via Photographic Print Toning on Wikipedia) Today, sepia toning is done digitally using a duotone process. All three of these processes were used on traditional silver print photos. Sepia is also the name given to the photographic toning process that creates a brownish tint to photographs and utilizes sodium sulfide, thiourea (or ‘thiocarbamide’), or polysulfide toners. It’s also the name of the color of ink derived from the cuttlefish (of the same name)’s ink (you know, squid ink?) used by many from the ancient Greeks and Romans up until the 19th century. What exactly is sepia? Well, it depends on who you ask. (Cuttlefish (Broadclub Cuttlefish) – Sepia latimanus by Jan (Arny) Messersmith (via Flickr) Similar problems occur when someone asks about a “good sepia.” They might even pronounce it differently. Someone else might think their coffee’s tangy roast with an astringent hint of lemon is more appealing than dark roast with a buttery finish. I might prefer a period drama over an action film. You might prefer a chardonnay over a merlot. Inevitably, everyone defines the characteristics a little differently. It’s like asking someone to recommend a good movie, book, bottle of wine, a brand of beer or the best coffee. This is inevitably a loaded question because sepia is a moving target. They ask me to help them pick out a “good sepia”. This article from the Smithsonian Institution also states that "Almost all cephalopods have an ink sac, a bladder that can suddenly release a plume of dense, black ink." Both of these are opposite the claim by our reader if he has other information, he should present it so that we can determine who is correct and prevent further confusion.At every pen show I’ve worked, at least one person will ask about a particular ink color. Accounting for the few species of Coleoidea which do not produce ink, one finds ~700 species of inking cephalopods compared to ~10 species of non-inking cephalopods. According to this review, members of Nautiloidea do not produce ink, but most of Coleoidea do produce ink. Subclass Nautiloidea has six extant (existing/living) species subclass Coleoidea has two subdivisions, Decapodiformes and Octopodiformes, each with several hundred living species. The taxonomic class Cephalopoda has two subclasses with living species, Nautiloidea and Coleoidea. Even if you limit yourself to squids, octopuses and sepias, there are more species that have no ink than species that do. I do think their ink is typically black, as this article says “Their ink, which is blackened by melanin, but also contains other constituents, has been used by humans in various ways for millennia.”įar from "all" cephalopods shoot out ink, let alone black. From what I have seen, the primary type of cephalopod humans interact with are Coleoidea (squid, octopus, etc.) so it may be common to drop the first term and just call these ink producers “cephalopods” in general, even though there is another subclass that does not produce ink. Here is what I think the confusion is- all Coleoidea cephalopods have ink sacs and produce ink, but members of the subclass Nautiloidea cephalopods do not. I found a peer reviewed article that discusses this: The ability to produce ink is therefore evolved from a common ancestor. Some nocturnal and deep-sea dwelling coleoideans has lost their ink sacs secondarily. Derby here, Coleoidean produces ink while nautiloidean does not. These pseudomorphs, or "false bodies" confuse the Retain a shape that looks similar to the squid. Of mucus helps the dark cloud that is released To distribute the ink, and increasing the amount The ink is mixed with a jet of water from the Small amount of ink out of the opening out the When the squid wants to release ink, itĬontracts the muscles of the sac, which pushes a Which is a muscular pouch that lies beneath the The ink itself is contained in an ink sac, Such as octopi and cuttlefish, use ink toĬonfuse their predators and thereby escape from Great question! Squids and other cephalopods, Ink from its ink-containing organ instead of Water (this is one of the ways that squid can Squid have an organ that contains ink inside of Ink so the predator will not be able to seeĬlearly and then the squids will swim away and They feel under attack, they will shoot out the The ink to help them escape from predators. Some water in the siphon, a part of their bodies Squid (and also octopus) belong to a group ofĪnimals called Cephalopods" and these animals most shoot out the ink. How does squid shoot the black ink out of it?
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