FOR AGES 3 YEARS TO 18 YEARS
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Kidadl provides inspiration to entertain and educate your children. We recognise that not all activities and ideas are appropriate and suitable for all children and families or in all circumstances. Our recommended activities are based on age but these are a guide. We recommend that these ideas are used as inspiration, that ideas are undertaken with appropriate adult supervision, and that each adult uses their own discretion and knowledge of their children to consider the safety and suitability.
Kidadl cannot accept liability for the execution of these ideas, and parental supervision is advised at all times, as safety is paramount. Anyone using the information provided by Kidadl does so at their own risk and we can not accept liability if things go wrong.
The day octopus (Octopus cyanea), also known as the big blue octopus after the typical blue circles on its body, is a unique species of octopus belonging to the family Octopodidae. With a body that can reach a size of at least 6.3 in (16 cm) with arms of around 31.5 in (80 cm), this highly intelligent and smart species of marine cephalopods can hide in plain sight due to their remarkable ability to camouflage. Even though these invertebrates have a typically brown-colored body, they can rapidly change their appearance to assume elaborate skin textures, colors, and patterns, helping them blend in with the surroundings. Since these octopuses feed during the daylight hours, their ability to camouflage is an exceptional defense mechanism against predators. Another bewildering quality of these cephalopods is that they can shoot out a dark cloud of black ink when threatened by predators.
Commonly found in the warm and shallow tropical Indo-Pacific waters from the coast of eastern Africa to the Hawaiian islands, the day octopus dens amidst coral reefs and other marine rubble. They are related to the squid and cuttlefish and feed on fishes as well as mollusk and crustacean prey such as crabs, shrimps, and bivalves.
There is a lot more to these quirky animals! Read on to find out.
If you like what you read, do check out more fun and interesting facts about octopus and California two-spot octopus at Kidadl.
The day octopus, or the big blue octopus (Octopus cyanea), is a species of marine cephalopods of the family Octopodidae.
Day octopuses belong to the class Cephalopoda, which also includes cuttlefish and squid.
The exact global population size of the day octopus (Octopus cyanea) is not known.
Day octopuses excavate dens amidst coral reefs, in the sand, or coral rubble. The coral reef may be located at depths of 3-328 ft (1-100 m) below the surface of the water. In addition, day octopuses can also be found dwelling in seagrass beds and rocky, sandy, or muddy ocean bottoms.
The natural geographical range and habitat of the day octopus include the tropical Indo-Pacific waters. These ocean-dwelling creatures are commonly found in warm and shallow marine environments, spanning from the Hawaiian Islands in the Pacific Ocean to the Red Sea around northeastern Africa. Some big blue octopuses have also been reported along the coasts of Seychelles, Somalia, Tanzania, Madagascar, as well as in the Mediterranean Sea.
The day octopus, or the big blue octopus, is mostly a solitary creature that does not interact with its own kind except during mating. These octopuses exhibit very aggressive behavior, and some larger individuals are even known to feed on smaller ones. They are quite socially repulsive animals and will choose to dwell in solitary dens if possible.
The big blue octopuses have an average lifespan of 12-15 months, both in the wild and in captivity. The longest recorded lifespan of these octopuses is 18 months in captivity as well as in the wild.
The mating behavior of male day octopuses is typically polygynous, meaning that one male may mate with several different females. Mating is not seasonal, and these octopuses generally reproduce all year round. However, female members breed only once during their lifetime and die soon after the eggs hatch because they stop eating and lose weight. Even in the case of males of the species, the suckers on the arms enlarge after they have mated several times. Once the suckers are fully enlarged, males lose the ability to change color and soon die.
Once these octopuses reach reproductive maturity at about 10-12 months of age, they start making spermatophores. Males use their fully-grown third right arm to insert the spermatophores into the mantle cavity of the female. Mating usually takes place on solid surfaces or inside a den during the day when the octopuses are foraging. After mating, a big blue octopus female will typically lay about 700,000 eggs on average, each measuring about 0.1 in (0.2 cm) in length and weighing around o.01 oz (0.2 g). The eggs take approximately 60 days to hatch, after which the female dies. Only the female day octopus participates in parental care of the eggs, taking meticulous care of the unborn young without even stopping to eat.
According to the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, the day octopus is a species of Least Concern.
The day octopus is an intelligent shape-shifter with an appearance more or similar to that of common octopuses. They can change not only their body color but also have a unique ability to alter the texture and pattern of their skin. The color changes in a way that it blends with the substrate as the octopus moves across the ocean floor.
Just like any other octopus (Octopus vulgaris), the big blue octopus has a massive head, eight long arms (modified muscular foot), and a reddish-brown skin tone. They lack the hard shell that usually characterizes other mollusks. When males reach about seven to nine months of age, they develop large suckers on the arms. In addition, these octopuses have dark and oval false eyespots devoid of the iridescent rings that mark the base of the arms. The dark eyespots are rarely visible, depending on the displayed patterns of individual members.
The big blue octopus is anything but cute. It rather looks like a huge blob of slime with hardly distinguishable features.
The ability to camouflage is not only a means of protection against predators but also a way to communicate with other octopuses. These animals are known to assume specific colors to communicate with each other. For instance, when males try to attract females, the former change into a darker color. Their eyesight is also quite well-developed, and they can spot prey from a distance of about 26 ft (8 m), waiting for the prey to come close enough so that it can be trapped. In addition, the big blue octopus can change colors rapidly like a flash of lightning to alert members of their own kind. The tactile senses of the males are used for mating.
The mantle length of the big blue octopus can go up to 6.3 in (16 cm), and the arm-to-arm length can be as much as 31.5 in (80 cm). Males have a longer third right arm which can reach a length of up to 19 in (48.2 cm). The big blue octopus is generally slightly smaller than the mimic octopus, which is around 23.6 in (60 cm).
The exact swimming speed of the big blue octopus is not known. However, they are known to crawl rather than being active swimmers.
The approximate weight of male and female big blue octopuses range between 7-232.6 oz (198.4-6594 g), with the average weight of the species being about 42.3 oz (1199.1 g).
Male and female octopuses are not known to have any distinct names.
When they hatch, any baby octopus is called a larva.
Big blue octopuses have a diverse diet, particularly when the availability of smaller prey is high. They hunt during the daytime and usually prey on small marine fish, molluscs, and crustaceans like crabs and shrimps. Juveniles have a similar diet that is predominated by small-sized prey. Interestingly, many bigger octopuses, like the Giant Pacific octopus are known to consume food in the range of 2-4 % of their own body weight!
Big blue octopuses are not known to be aggressive or dangerous towards humans. However, these ocean creatures can exhibit aggressive behavior towards each other, with larger individuals devouring smaller ones. Females are specifically known to show cannibalistic behavior during the breeding season, a phenomenon known as sexual cannibalism. When threatened by predators, these octopuses squirt a cloud of black ink to blind the predator and inhibit the latter's sense of smell.
In general, octopuses do not make great pets, and they are better left in their natural ocean habitat among rocks and coral reefs. The price of pet octopus species can range between 20-1,000 USD and keeping them as pets can be quite a costly affair.
The species name cyanea of the big blue octopus (Octopus cyanea) is a Greek term meaning sky blue, inspired by the blue rings on the octopus's skin.
During pre-mating courtship, the male day octopuses show a dark brown body color with white spots. On the other hand, females are in full camouflage and do not don the white spots.
Like other octopus species, the big blue octopus has three hearts. Surprisingly, one of these three hearts stops beating when the animals are swimming, perhaps due to some physiological reason.
The big blue octopus can change their body color naturally due to the presence of specialized skin cells called chromatophores.
The big blue octopus has salivary glands that can secrete venom. The poisonous substance ejected from the salivary glands is used by the animal to kill its prey; the octopus then uses its sharp beak to crack open the shell of the prey (such as snails and crabs). In addition, the predator octopus also has the ability to drill holes in the prey's shell with its radula (rasping organ) to inject a substance that separates the prey's flesh from its shell.
Fun fact: octopuses are thought to be quite smart as they have a memory and can learn things quite fast. Many octopuses can also find their way around mazes!
Yes, unlike other species of octopus, like the blue-ringed octopus, the big blue octopus is a daytime hunter.
Octopuses have nine brains, a central one in addition to eight smaller ones to control each of the eight arms independently.
Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! For more relatable content, check out these coconut octopus facts and Giant Pacific octopus facts pages.
You can even occupy yourself at home by coloring in one of our free printable O is for octopus coloring pages.
Read The Disclaimer
At Kidadl we pride ourselves on offering families original ideas to make the most of time spent together at home or out and about, wherever you are in the world. We strive to recommend the very best things that are suggested by our community and are things we would do ourselves - our aim is to be the trusted friend to parents.
We try our very best, but cannot guarantee perfection. We will always aim to give you accurate information at the date of publication - however, information does change, so it’s important you do your own research, double-check and make the decision that is right for your family.
Kidadl provides inspiration to entertain and educate your children. We recognise that not all activities and ideas are appropriate and suitable for all children and families or in all circumstances. Our recommended activities are based on age but these are a guide. We recommend that these ideas are used as inspiration, that ideas are undertaken with appropriate adult supervision, and that each adult uses their own discretion and knowledge of their children to consider the safety and suitability.
Kidadl cannot accept liability for the execution of these ideas, and parental supervision is advised at all times, as safety is paramount. Anyone using the information provided by Kidadl does so at their own risk and we can not accept liability if things go wrong.
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