Cuttlefish are marine animals closely related to squid, octopus, and nautilus. They are in the taxonomic class Cephalopoda, but differ from their other cephalopod cousins slightly. Because of this, scientists place them in their own order, Sepiida. These creatures resemble fat squids with short arms and tentacles, and they vary greatly in size. Read on to learn about the cuttlefish.
Description of the Cuttlefish
Like their cousin the squid, These creatures have a long mantle. However, unlike squid, which have two triangular fins on either side of the mantle, s have a single, long, undulating fin running down either side of their mantle. There are many species of cuttlefish, and they range drastically in size. While the average cuttlefish is 6 – 10 in. long, the largest species can grow up to 20 in. long!
Interesting Facts About the Cuttlefish
Don’t let their appearance or size fool you, these creatures are remarkably intelligent. Just like their cousin the octopus, cuttlefish are surprisingly intelligent compared to other invertebrates.
- Weird Eyes – Unlike humans and many other animals, which have round pupils, cuttlefish have “W” shaped pupils. Their odd eyes are unique because they have no blind spots at all. These cephalopods can see in objects front of them, and objects behind them, at the same time.
- Cuttlebone – While fish have a swim bladder, and sharks have an oil-filled liver, cuttlefish have a different way to remain buoyant in the water. They use a porous structure, conveniently called a cuttlebone, to stay neutrally buoyant. This allows them to “float” in place in the water, without sinking or rising. No other animal, not even other cephalopods, have the same structure.
- Safe to Eat? – Before chowing down on, or playing with, any cuttlefish you find, it is important to remember that some species can be dangerous. A few species have toxic venom, and when they bite you it can make you very sick. One species has highly toxic poison in its muscles, which can kill you if you eat it!
- Colorfish – Like other cephalopods, these species have the ability to change the color of their skin. Their pores contain sacs called chromatophores that have different colored pigments inside. They use these chromatophores to change colors, and even produce color patterns or flashes across the skin.
Habitat of the Cuttlefish
All of the different species live in tropical or temperate waters. They are all oceanic, and need to live in saltwater to survive. Most species live in shallow waters, but some species will range as far as 2,000 ft. beneath the surface of the water. Different species live in seagrass beds, coral reefs, rocky outcrops, sandy seafloor, and more.
Distribution of the Cuttlefish
The various species range across most temperate and tropical seas across the world, save for those off the coast of North, Central, and South America. They can be found in coastal waters near Asia, Europe, Africa, and Australia, as well as the Mediterranean Sea and Baltic Sea. Each species has its own specific range and habitat, and some species overlap with others.
Diet of the Cuttlefish
While each species is different, most have a relatively similar diet. While they are young, most of their diet consists of small shrimp and crustaceans, including larvae. As they grow older, they graduate to fish, crabs, and other mollusks.
While hunting, these creatures use their color-changing skin as camouflage to sneak up on prey. Once they locate a food source, they will spray a jet of water to uncover it, and then they snag it with their two long tentacles and secure it with their arms.
Cuttlefish and Human Interaction
The population of each species varies greatly. Some, like the common cuttlefish, are widespread and their populations are stable. However, we have not evaluated many species, and humans are currently threatening others.
People commonly eat them, and sometimes use their ink to flavor seafood and pasta, and change the color of some foods. People also use their ink as dye, but this is less common in current times than it was in the past. Their cuttlebones provide a good calcium supplement for pet birds, like parakeets.
Humans have not domesticated cuttlefish in any way.
Does the Cuttlefish Make a Good Pet
Though these creatures can make good aquarium pets, they do not have very long lifespans. Some species, including common cuttlefish and dwarf cuttlefish, live well in aquariums. If you keep them as pets, you cannot handle them, and they will eat any other fish in the tank.
In an aquarium setting, the species of cuttlefish will determine what temperature, pH, salinity, and other factors you need to maintain. Most require an environment similar to their native habitats. Some species successfully breed in aquariums, and this allows scientists to research their intelligence, color-changing ability, ink, and more. Most species can eat a diet of fish and crustaceans successfully.
Behavior of the Cuttlefish
While behavior varies based upon the species, all cuttlefish use their colors and patterns to communicate with one another. They use different colors to express when they are searching for a mate, territorial, calm, aggressive, and more. Some males will even change their color and pretend to be females so that they can mate with a female while another male is nearby guarding her.
Reproduction of the Cuttlefish
Reproduction varies based upon the species. All species of this fish use color and pattern to court mates, but the exact specifics of these changes vary by species. They use a breeding season to reproduce, and will congregate to spawn.
They fertilize their eggs internally, and larger females produce more eggs. Small females can produce hundreds of eggs, and larger females can produce upwards of one thousand. She will lay the eggs between one and three months after mating.