Cuttlefish

Cuttlefish
Georgia Aquarium - Cuttlefish Jan 2006.jpg
Two cuttlefish interact while a third looks on. Georgia Aquarium
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Coleoidea
Superorder: Decapodiformes
Order: Sepiida
Zittel, 1895
Video of a cuttlefish in its natural habitat
A cuttlebone from a sepia
Two photos of cuttlefish with dramatically different coloration
This Broadclub Cuttlefish (Sepia latimanus) can go from camouflage tans and browns (top) to yellow with dark highlights (bottom) in less than a second.
Sepia latimanus, East Timor
An infant cuttlefish protects itself with camouflage

Cuttlefish are marine Cephalopod molluscs. They belong to the same class as squid, octopodes and the nautilus.

Cuttlefish have an internal shell (called a cuttlebone), large eyes, and eight arms and two tentacles furnished with finely toothed suckers, with which they grab their prey.

Cuttlefish eat small molluscs, crabs, shrimp, fish and other cuttlefish. Various sharks and fish prey on them. They live about 1 to 2 years.

Anatomy

Cuttlebone

Cuttlefish have an internal cuttlebone, made of calcium carbonate. It is porous, full of small holes, The buoyancy of the cuttlebone can change, allowing the cuttlefish to go lower or higher by changing the amount of gas and liquid in its chambers. The cuttlebone of each species has a distinct shape, size, and pattern of ridges or texture. Cuttlebones are used by jewellers and silversmiths as moulds for casting small objects. They are probably better known today as the material given to pet birds as a source of calcium. The cuttlebone is only found in cuttlefish, and is one of the features that makes them different from squid and other molluscs.

Changing color

Cuttlefish are sometimes called the chameleon of the sea because they are able to change their skin color. Their skin can flash a colorful pattern in order to communicate with other cuttlefish and to camouflage them from predators. This color-changing function is produced by groups of red, yellow, brown, and black pigmented chromatophores above a layer of reflective iridophores and leucophores. These are all in the cuttlefish's skin, and work together to change its colour. There are up to 200 of these special pigment cells per square millimeter.

The pigmented chromatophores have a sac of pigment and a large membrane that is folded when retracted. There are 6-20 small muscle cells on the sides which can contract to squash the elastic sac into a disc against the skin.

Iridophores are plates of chitin or protein, which can reflect light. They are responsible for the metallic blues, greens, golds, and silvers often seen on cuttlefish. All of these cells can be used in combinations. As well as being able to influence the colour of the light that reflects off their skin, cuttlefish can also affect the light's polarization, which can be used to signal to other animals which sense polarization.

Eyes

Cuttlefish eyes are among the most developed in the animal kingdom. The way cephalopod eyes develop is fundamentally different from that of vertebrates like humans, but the way they work is rather similar. [1] The similarity between cephalopod and vertebrate eyes is an examples of convergent evolution. Although they cannot see color, they can perceive the polarization of light, which improves their ability to see contrast. They have two spots of concentrated sensor cells on their retina (known as fovea), one to look more forward, and one to look more backwards. The lenses, instead of being reshaped as they are in humans, are instead pulled around by reshaping the entire eye in order to change focus.

Pfeffer's Flamboyant Cuttlefish, from Sipadan, Malaysia

Blood

The blood of a cuttlefish is an unusual shade of green-blue because it uses the copper-containing protein haemocyanin to carry oxygen instead of the red iron-containing protein haemoglobin that is found in vertebrates. This is similar to the blood of arthropods. Haemocyanin is not so good at carrying oxygen as is haemoglobin. The blood is pumped by three separate ' hearts'. Two of these are used for pumping blood to the cuttlefish's pair of gills (one heart for each gill), and the third for pumping blood around the rest of the body.

Other Languages
العربية: حبار
অসমীয়া: কাটলফিছ
Bân-lâm-gú: Hoe-ki
беларуская: Каракаціцы
български: Сепии
brezhoneg: Morgad
català: Sèpia
Cebuano: Sepiida
čeština: Sépie (řád)
Deutsch: Sepien
Ελληνικά: Σουπιά
English: Cuttlefish
español: Sepiida
euskara: Txibia
فارسی: سپیداج
français: Sepiida
Gaeilge: Cudal
galego: Sepideos
한국어: 갑오징어목
हिन्दी: समुद्रफेनी
hrvatski: Sipe
Ido: Sepio
Bahasa Indonesia: Sotong
italiano: Sepiida
עברית: דיונונים
Basa Jawa: Sotong
қазақша: Тарбақ аяқ
Kiswahili: Dome
lietuvių: Sepijos
magyar: Tintahalak
മലയാളം: കണവ
Bahasa Melayu: Sotong Katak
Mìng-dĕ̤ng-ngṳ̄: Dĕ̤ng-kiĕ
日本語: コウイカ目
norsk: Sepiida
Plattdüütsch: Echte Dintenfische
polski: Mątwy
português: Choco
русский: Каракатицы
slovenčina: Sépie
slovenščina: Sipe
српски / srpski: Сипе
Basa Sunda: Balakutak
suomi: Seepiat
українська: Каракатиця
Tiếng Việt: Bộ Mực nang
文言:
Winaray: Bagulan
粵語: 墨魚
中文: 墨鱼目