Just like horseshoe crab is not a crab, cuttlefish is not a fish! Interesting, isn’t it? Read more amazing facts about cuttlefish from this article.

Facts About Cuttlefish

The most interesting fact about cuttlefish is that it is not a fish! Cuttlefish is a cephalopod mollusca and is a close kin of other marine animals like octopus, squid, etc. Cuttlefish is often confused with squids because of its close resemblance with each other, but squid lacks cuttlebone. Cuttlefish has amazing camouflage mechanism and is regarded as the ‘most intelligent invertebrate’. This mollusc has a flat body with lateral fins. Unlike a fish that uses fins as its primary locomotors organs, cuttlefish use it as stabilizers or steering.  It depends on water-jet for faster locomotion. It is well-known for its defense mechanism—spurting ink on the enemies. Ironically, this defense mechanism has become its biggest threat, as today, cuttlefish is primarily hunted for the ink. Cuttlefish are the favorite food not only for marine animals, but also for human beings. Read for more interesting facts about this marine animal.

Fast Facts

Type                          Marine animal
Class                         Cephalopoda
Order                         Sepiida
Family                        Sepiidae
Genus                        Sepia
Diet                             Carnivorous
Size                            15mm – 1m
Weight                       Up to 10 kg
Lifespan                    About 2 years
Habitat                       Shallow areas and reefs of tropical and temperate seas
Number of eggs      Around 200
Hatching Period     About 4 months

 Amazing And Interesting Facts About Cuttlefish

  • The internal shell of cuttlefish is known as cuttlebone that helps in buoyancy.
  • Light is highly related to the buoyancy of the cuttlefish. Buoyancy decreases in the presence of light and hence, cuttlefish becomes active during night and swims freely up and down the water.
  • The cuttlebone is porous and is made of aragonite and has air-filled spaces that regulate the gas-liquid ratio by pumping liquid in or out. This is how it helps in regulating buoyancy.
  • Jewelers and silversmiths use cuttlebone for casting small objects. They are good source of calcium and hence, used to feed caged birds as a dietary calcium supplement.
  • Cuttlefish has eight arms and a pair of tentacles equipped with suckers. These tentacles help it to hunt its prey. Cuttlefish protracts the tentacles only when they are needed. The mouth is situated amidst the tentacles.
  • Cuttlefish has a pair of large lateral fins that aids in movement. The fins are generally used as steering and stabilizer. They help to propel the animal too, but in slow movements. For faster swimming, they depend on water-powered jet propulsion. This is done by forceful expulsion of water from the mantle cavity.
  • These animals are blessed with excellent camouflage adaptations; they can change their color according to the surroundings. They are rightly named as the ‘chameleon of the sea’!
  • Cuttlefish use this camouflage mechanism for communication, predation and attracting mate as well. They are the fastest color changers in the animal kingdom.
  • Cuttlefish owe their ability to change color to the pigmented cells called chromatephores . Xanthophores are related to yellow color, erythrophores to red and orange and melanophore to black and brown. All these cell are used either single or in combination with other cells to produce the desired color. 
  • Cuttlefishes are generally about 15-36 cm long but a giant cuttlefish reaches up to 80 cm of length.
  • Shallow water areas and reefs of temperate and tropical seas around the world form their favorite habitats.
  • Cuttlefish feed on small molluscs, fishes, shrimps, octopuses and other cuttlefishes. Their common predators are sharks, large fishes, seabirds, seals, dolphins etc.
  • It releases protein-based ink stored in the ink sac when alarmed to frighten or confuse the enemy.  
  • Cuttlefish cannot see color, but they can recognize the polarization of light that helps them distinguish the contrast.
  • Cuttlefish can shift its lens to change the focus, unlike the mammals that reshape the lens. It can see backward as well.
  • Cuttlefish has a ‘w’ shaped pupil.
  • Amazingly, the eyes are completely developed even before the babies hatches out from the eggs, which means they can see their surroundings even before hatching. Some researchers claim that the cuttlefish hunt the prey they saw before hatching!
  • Cuttlefish has blue-green blood! This is because of the oxygen carrying pigmenthHemocyanin in their blood. This pigment contains copper in it.
  • Cuttlefish has three hearts to assist circulation. It has two branchial hearts, one each for the gills each and the third one for the whole body.
  • Hemocyanin is not a good oxygen carrier and hence, cuttlefish needs rapid circulation.
  • Cuttlefish has neurotoxins in their saliva. This toxic substance is produced by bacteria. Pfeffer’s Flamboyant Cuttlefish has the most poisonous substance but it is yet to be identified.
  • Cuttlefish is a favorite food in many parts of the world. Dried, shredded cuttlefish is a favorite snack.
  • The cuttlefish ink ‘sepia’ was separated and used earlier but now artificial dyes have replaced the natural one.
  • Male cuttlefish change their colors during mating season to attract the females. Some of them assume the appearance of female to fool the dominant males so that they don’t sweep them over and pair with their mates.
  • The male cuttlefish has a special tentacle called hectacotylus, a spoon-shaped tentacle used to deposit sperms in the female’s mantle cavity.
  • The cuttlefish has a funnel like opening which has multiple uses - as female sex organ, as an outlet for jet propulsion, as an ink gland.

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