By Colin Dunlop - 2003
Discuss this article in our forums: Cuttlefish Care
When is a fish not a fish? Em... okay, er... em... It's not a funny joke, actually it's just a fact... cuttlefish are not fish!
Cuttlefish are much more closely related to garden slugs and snails than they are to fish! They belong to the same group of animals as the octopuses, squid and nautilus and like a snail they are all molluscs.
Cuttlefish are unique within this group in that they have a gas filled bone within their bodies which allows them to be buoyant... you may have seen cuttlebones before, sticking out from the bars on a budgie's cage? The bone is within the body part of the animal called the mantle and attached to the mantle is a head with eight arms and two feeding tentacles.
A six-month-old captive European Cuttlefish
The cuttlefish is an ambush predator and a master of disguise. Its skin is covered with special cells called chromatophores, iridophores and leucophores that reflect light in many different colours enabling the cuttlefish to blend into its background almost perfectly. Some say it's like a chameleon but it is far superior in its ability to change colour and even the texture of its skin!
Viewed from above this captive cuttlefish blends into the substrate.
A cuttlefish will steadily, using its camouflage, sneak up on its prey. Their preferred diet is crabs or fish, and when it is close enough it opens apart its eight arms and out shoots two deceptively long feeding tentacle. On the end of each is a pad covered in suckers that grasp hold of the prey and quickly pull it close to the cuttlefish's mouth that looks like a parrot's beak.
A tame cuttlefish grabs foods using its feeding tentacles
The scientific name for a cuttlefish is Sepia. In years gone by sepia ink, which is derived from cuttlefish, was used by artists for their paintings. For the cuttlefish this ink is a decoy, a means of escape from predators. If a large fish were to attack a cuttlefish it would eject a cloud of dark brown, almost black ink towards its attacker! The predator would get a mouthful of ink that tastes nasty and coats its nostrils. Meanwhile the cuttlefish is hidden from view and propels itself away backwards by using its own jet propulsion system, its siphon.
The eggs of cuttlefish are laid in clumps together and are often coated in ink from the mother; this serves as camouflage for the eggs. They hatch at a much further developed stage than an octopus does and immediately start feeding on suitably small shrimps.
Cuttlefish keep their arms out of the reach of crab's claws!
Many people would like to keep cuttlefish as pets. This is quite easy in the UK and Europe as species of cuttlefish like Sepia officinalis the 'European cuttlefish' are found there.
In the USA however, there are no naturally found species and the most commonly imported species is from Bali called Sepia bandensis which is a poor traveller and normally arrives as a four-inch adult with perhaps only weeks to live. It is not recommended as a pet. One day someone will be captive breeding Sepia officinalis for the American hobby!