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The Pharaoh cuttlefish (Sepia pharaonis) is a large cuttlefish species, growing to 42 cm in mantle length and 5 kg in weight.[1] When raised in the laboratory, the maximum recorded size for males is 16.2 cm, and for females 15.5 cm.[2]

Sepia pharaonis is likely a complex of at least three species, Sepia pharaonis I, commonly located in the Red Sea and Arabian Gulf, S. pharaonis II, located from Japan to the Gulf of Thailand and northern Australia; and S. pharaonis III, located from the Indian Ocean to the Andaman Sea.[1]

The type specimen was collected in the Gulf of Suez and is deposited at the Zoologisches Museum in Berlin.[3]

Range and Habitat[edit]

Sepia pharaonis photographed off the coast of Egypt

The Pharaoh cuttlefish is native to at least the western Indian Ocean, including the Red Sea and Persian Gulf.[4] Of all the cuttlefish species in the Persian Gulf, it is the most commonly caught. Inhabiting the neritic zone, it is often found in depths up to 130 m.[2] When hunting at night, it swims up to shallower parts of the sea to feast on a variety of smaller fish, crabs, and occasionally other cuttlefish.[5]

They have been observed to exhibit migratory behavior off of the south-west coast of India.[2] They are more commonly found furthest north during August, and further south in May.[2] They show an even distribution in October and Febuary. Additionally, there are more juveniles present in May, and more adults present in August.[2]

The Pharaoh cuttlefish prefer a medium to high amount of sunlight for den location during the day. Additionally, they prefer mud substrata during the day, but during the night prefer sand or mud substrata equally.[3]

Reproduction[edit]

Spawning times vary depending on its habitat. Near Hong Kong, it mates during Spring, from March to May. In the Red Sea area, mating takes place from August to October.[5] After mating, the female deposits her eggs near the coast, between depths of 5 and 20 m, sometimes covering them in ink for extra camouflage.[2]

Pharaoh cuttlefish reproduce the same way as most other cuttlefish. Large males compete in combat until a victor is decided. This combat is often decided without any physical contact. The males circle each other performing threatening displays of color and tentacles until one male swims off in defeat. The victorious male then mates with females by grabbing them with their tentacles, turning the female so that the two animals are face-to-face, then using a specialized tentacle to insert sperm sacs into an opening near the female's mouth. The male then guards the female until she lays the fertilized eggs a few hours later.

Coloring[edit]

Pharaoh cuttlefish often show a solid color when resting on a solid color background, alternating from a pale white to all dark brown. Additionally, they can show a mottled white and brown color, with a center circle of brown. The mechanism for color is the same in the Pharaoh cuttlefish as it is in other cuttlefish. This colour-changing function is produced by groups of red, yellow, brown, and black[4] pigmented chromatophores above a layer of reflective blue and green tinted iridophores and leucophores, with up to 200 of these specialized pigment cells per square millimeter.[5] These sacs of color are controlled by rings of muscle around the sac. The cuttlefish expands and contracts these muscle rings in order to show different colors.

Human uses[edit]

It is a commonly fished species of cuttlefish in the Philippines, as well as the most economically important cuttlefish in the northern Indian Ocean. Off the coast of Australia, 90% of the cuttlefish caught are S. pharaonis.[2] It is often eaten by humans in these areas. Typically, cuttlefish is consumed as dried, shredded cuttlefish, a popular snack food. And, in the Qing Dynasty manual of Chinese gastronomy, the Suiyuan shidan, the roe of the cuttlefish is considered a difficult to prepare but sought-after delicacy.[6]

Additionally in the past Cuttlefish ink was an important dye, called sepia. Today, artificial dyes have mostly replaced natural sepia.

See also[edit]

  • Cephalopod size
  • Common cuttlefish
  • Chromatophores
  • Cuttlefish

References[edit]

  1. Jump up^ Reid, A., P. Jereb, & C.F.E. Roper 2005. Family Sepiidae. In: P. Jereb & C.F.E. Roper, eds. Cephalopods of the world. An annotated and illustrated catalogue of species known to date. Volume 1. Chambered nautiluses and sepioids (Nautilidae, Sepiidae, Sepiolidae, Sepiadariidae, Idiosepiidae and Spirulidae). FAO Species Catalogue for Fishery Purposes. No. 4, Vol. 1. Rome, FAO. pp. 57–152.
  2. Jump up to:a b c d 
  3. Jump up^ Current Classification of Recent Cephalopoda.
  4. Jump up^ Norman, M.D. 2000. Cephalopods: A World Guide. ConchBooks.
  5. Jump up to:a b
    1. ^ "Sepia pharaonis (Pharaoh Cuttlefish)". www.iucnredlist.org. Retrieved 2016-03-24.
    2. ^ a b c Chembian, John (1/8/2011). "Migration and spawning behavior of the pharaoh cuttlefish sepia pharaonis". Indian Journal of Fisheries. Retrieved 3/24/2016. {{cite journal}}: Check date values in: |access-date= and |date= (help)
    3. ^ "Behaviour of Juvenile Cephalopods: Preference for Texture and Brightness of Substrata". ResearchGate. Retrieved 2016-03-24.
    4. ^ Messenger, J. B. (2001-11-01). "Cephalopod chromatophores: neurobiology and natural history". Biological Reviews. 76 (4): 473–528. doi:10.1017/S1464793101005772. ISSN 1469-185X.
    5. ^ "NOVA | Kings of Camouflage | Anatomy of a Cuttlefish (non-Flash) | PBS". www.pbs.org. Retrieved 2016-03-29.
    6. ^ "Page not found – Translating the Suiyuan Shidan". Retrieved 2016-03-29. {{cite web}}: Cite uses generic title (help)

    Context Memo[edit]

    I chose to improve on the Pharaoh cuttlefish article because it is something I am interested in, and I have a lot of background information already from doing my project 2. The main bulk of what I added was various cleaning up of the page and I also added more information on their general range and breeding habits. I changed the Ecology section, which was very broad, into a "reproduction" and "range and habitat" section. Additionally I added 4 new sources to the article and added a section on general coloring. All of this information is encyclopedic because it is just facts that have been backed up in well known journals. None of this information is opinionated because I don't use words like "better than" or "smarter than" or other words that could convey an opinion. The information I added is also neutral, it doesn't take any sides or try and make a certain point. All the information I added is factual and I didn't add any embellishments of my own.