Cuttlefish not only change their colour to match their surroundings. They have what appears to be a language of thousands of colours and gestures. Researchers studying cuttlefish in tanks find that they swim up to the side of the tank and make specific colour displays when certain researchers enter the room. This seems to indicate recognition and memory, the desire to communicate. Perhaps they are saying, "Ohayo!" or "Good Morning!" or "You again. Did your mother dress you? You are such a loser." No one knows. But it seems they are saying something.

Cuttlefish, octupi, and squid are common in Mediterranean and Asian diets. Dried cuttlefish are packaged as cheap snacks...

I have learned two very odd but interesting things about cuttlefish courtesy of the Discovery Channel.

  1. The cuttlefish does not see as we humans do or even our friends canis familiaris. No, the cuttlefish sees bent light. "Now," you say, "what the hell use would seeing bent light be?" Not much, if you are you or me, but if your food consists of transparent shrimp, seeing bent light just might help you find dinner.
  2. The other interesting thing about cuttlefish is their manner of catching/attacking said shrimp. The cuttlefish moves all but two of its tentacles up in front of itself, twisted in a strange pattern, such that it really does look from the front like a big mass of tangled seaweed. Now, since it's a cephalopod, it has a siphon propulsion system. This allows it to move forward slowly and silently, still looking like a tangled mass of seaweed. At this point it launches out its last two tentacles from within the others, and grabs the little shrimp with them, pulling it back to its beak with which it crushes and consumes it. Cool, huh?


Kingdom Animalia
Phylum Mollusca
Class Cephalopoda
Subclass Coleoidea
Superorder Decapodiformes
Order Sepiida

 

The cuttlefish is a small cephalopod that inhabits all temperate oceans except those surrounding the Americas. Its mantle (body without arms) achieves a football's proportions.

Like other cephalopods, it keeps most of its organs in the squishy sack above its eyes. The mantle is fringed on each side with a short fin that ripples like a flag. It has eight arms and two long tentacles; the tentacles retract completely into the body and extend as though spring-loaded to capture prey. It has a beak, and discharges ink when agitated--in this case the useful pigment sepia. Quick movements are accomplished with jet power, generated by a siphon. It eats small crustaceans and fish and other cuttlefish.

The cuttlebone is the most well-known part of the cuttlefish. It functions as a swim bladder: the cuttlefish changes depth by injecting or pulling gas into/out of the bone. The cuttlebone prevents the cuttlefish from venturing into deep waters by imploding. It is rich in calcium and salt and makes a good supplement for a pet bird.

The cuttlefish has sophisticated eyes. The pupils are wavy and cross the eyes horizontally--like in a goat's eyes, only weirder. The pupils bend incoming light to reveal transparent prey.

Cuttlefish have short lives, as cephalopods do. One to two years.

Mating cycles occur year-round, spiking in March and June. Males deposit sperm with a hectocotylized arm, an arm specialized for mating. Eggs are large, about 6-9 millimeters, and are stored in the female's oviduct until distribution in clumps on the sea floor. Typically the eggs are tinted with sepia to blend with the sand. After roughly two months the young hatch with a supply of yolk that serves them until they are able to secure prey, which is soon. Cuttlefish hatchlings are more formidable than those of squid or octopus and are able to overpower small crustaceans almost immediately.

The cuttlefish's blood is greenish blue, like an alien. The color results from the pigment hemocyanin, which carries oxygen; in red-blooded animals oxygen is carried by hemoglobin

The cuttlefish is called the chameleon of the sea, which is generous to chameleons. In cuttlefish, color changes are accomplished instantly by small structures in the skin called chromatophores, leucophores and iridophores--tiny bags of ink that contract and expand to create color like pixels on a screen.  They come in colors red, yellow, brown, and black. A layer of chromatophores is above a layer of iridophores; iridophores make a layer above leucophores. Each square millimeter of skin can contain 200 bags of pigment. Colors are used to hide from predators and to communicate with other cuttlefish; basic color is a mottled black or brown. Cuttlefish can also change their skin's texture.

Cuttlefish are kept as pets primarily in the UK. They're said to be very much like cats, in that they rest, pounce, and beg for food even when they're fat. Cuttlefish imported to the US as pets are typically the poor-traveling Balinese Sepia bandensis, which arrive four inches long and have weeks to live.

Cuttlefish are demanding creatures to keep. The saltiness of their water must be proportional to their body size, and their tanks need to be cleaned every time they ink. They also cannot handle abrupt changes in light.

 


 

sources

Divernet
http://www.divernet.com/biolog/cuttle899.htm

Wikipedia
http://en.wikipedia.org/wiki/Cuttlefish

Marinebio dot org
http://www.marinebio.org/species.asp?id=540

Abyss Scuba Diving
http://www.abyss.com.au/cuttle.html

Cut"tle (kut"t'l), Cut"tle*fish` (-f?sh`), n. [OE. codule, AS. cudele; akin to G. kuttelfish; cf. G. ktel, D. keutel, dirt from the guts, G. kuttel bowels, entrails. AS. cwip womb, Gith. qipus belly, womb.]

1. Zool.

A cephalopod of the genus Sepia, having an internal shell, large eyes, and ten arms furnished with denticulated suckers, by means of which it secures its prey. The name is sometimes applied to dibranchiate cephalopods generally.

It has an ink bag, opening into the siphon, from which, when pursued, it throws out a dark liquid that clouds the water, enabling it to escape observation.

2.

A foul-mouthed fellow.

"An you play the saucy cuttle me." Shak.

 

© Webster 1913.

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