90 Interesting Facts About Octopuses

Here are 90 interesting facts about octopuses:

1. Octopuses belong to a group of animals called cephalopods, which also include squid and cuttlefish.
2. They’re among the most intelligent invertebrates, possessing both short- and long-term memory.
3. Octopuses have three hearts – two pump blood to the gills and the third to the rest of the body.
4. When an octopus swims, the heart that pumps blood to the rest of the body stops beating, which is why octopuses prefer to crawl rather than swim, conserving energy.
5. Octopuses have blue blood due to a copper-based protein called haemocyanin.
6. They’re extremely flexible because they don’t have a rigid skeleton.
7. An octopus can squeeze through any opening larger than its beak, the only hard part of its body.
8. Octopuses have excellent eyesight and can detect polarised light.
9. They’re masters of camouflage. An octopus can change its colour, pattern, and even texture to blend in with its surroundings.
10. This ability to change appearance is used not only for hiding but also for communicating with other octopuses, hunting, and courting.
11. Some species of octopus are venomous.
12. The most venomous octopus is the blue-ringed octopus, which carries enough venom to kill 26 adult humans within minutes.
13. Octopuses have beaks similar to a parrot’s which they use to crack open shellfish.
14. In the centre of the arms of an octopus, you will find its mouth, which houses this sharp beak.
15. Each of an octopus’s eight arms is lined with about 240 suckers, each one capable of taste and touch.
16. Octopus arms are semi-autonomous. Even when severed, an arm will react to stimuli and try to grasp food.
17. The suckers of an octopus are so sensitive, they can pick up subtle chemical signals in the water.
18. They are solitary creatures and prefer to be alone, except during mating.
19. In most species, the male octopus dies a few months after mating. Females die shortly after their eggs hatch as they stop eating to guard their eggs.
20. An octopus uses ink to confuse and escape from predators. This ink also temporarily paralyses the predator’s senses.
21. Octopuses are capable of regenerating lost arms.
22. The Giant Pacific Octopus, the largest species, can grow up to 30 feet across and weigh more than 600 pounds.
23. The smallest species, the Octopus wolfi, is only about 2.5 cm in size and weighs less than a gram.
24. An octopus has approximately 500 million neurons, more than six times the number in a mouse’s brain.
25. Octopuses have been known to use tools, like coconut shells for shelter or rocks to block their den entrances.
26. They have been observed playing, engaging with toys, and solving puzzles in captivity.
27. Octopuses can walk on two arms, using the other six as a disguise.
28. An octopus’s skin can sense light, even without input from the eyes or brain.
29. They have distinct personalities and can exhibit traits like curiosity, assertiveness, and even playfulness.
30. Octopuses have relatively short lifespans, ranging from only half a year for some species to up to five years for others.
31. Some species of octopuses exhibit astounding abilities to mimic other animals, like flounder, sea snakes, and lionfish.
32. Octopuses can “taste” with their arms. This sense of taste comes from chemoreceptors on their suckers.
33. The eggs of octopuses can range from the size of a grain of rice to the size of a grape.
34. A single octopus can lay up to 400,000 eggs, but only a few usually survive to adulthood.
35. Octopuses are known for their Houdini-like escapes in both wild and captive settings due to their problem-solving skills.
36. They can move in any direction and alter their body shape, which helps in hunting and evading predators.
37. Octopuses are poikilothermic animals, meaning they can change their body temperature according to their environment.
38. Some species of octopuses, like the blanket octopus, exhibit extreme sexual dimorphism, where females can be up to 40,000 times heavier than males.
39. Despite being soft-bodied, octopuses are formidable hunters, feeding on shrimps, lobsters, and even small sharks.
40. They are known to use a ‘jet propulsion’ method for rapid escape, where water is forcefully ejected from a siphon on their bodies.
41. Octopuses show diurnal rhythms, meaning they have specific periods of rest and activity.
42. They are known for their remarkable growth rates. The Giant Pacific Octopus grows from the size of a rice grain to 100 pounds in just two years.
43. Octopuses don’t have any auditory organs, so they don’t hear sounds like we do.
44. They can detect local electric fields, which is helpful for locating prey.
45. The seven-arm octopus (Haliphron atlanticus) is so-called because in males, the hectocotylus (a specially modified arm used in egg fertilization) is coiled in a sac beneath the right eye and is often mistaken for a missing arm.
46. Some deep-sea octopuses like Graneledone boreopacifica have the longest known brooding period of any animal. They guard their eggs for an astonishing 4.5 years!
47. There’s an octopus species known as the Dumbo octopus that has ear-like fins protruding from its head, resembling the ears of Disney’s Dumbo the elephant.
48. The Argonaut octopus has a shell, a rarity among octopuses. Females construct a thin, white, paper-like shell to use as a brood chamber.
49. The octopus’s nervous system is highly complex, with two-thirds of its neurons located in the nerve cord of its arms.
50. The Southern Sand Octopus can build a quicksand-like lair by shooting jets of water into the seabed.
51. Octopuses don’t have tentacles – they have arms. The term ‘tentacles’ is reserved for appendages that are typically longer than arms and have a small sucker, or none at all, at the end.
52. Octopuses have a sense of touch that extends to their skin, allowing them to change their colouration upon touching different surfaces.
53. Some octopuses exhibit bipedal locomotion, meaning they walk on two of their arms.
54. They don’t have blind spots because their pupils are rectangular and allow them to focus light from all directions.
55. The nervous system of an octopus is distributed, meaning it doesn’t entirely rely on a central brain for command. Some decisions are made by clusters of neurons in its arms.
56. The intelligence of an octopus is thought to have evolved to help it in complex tasks like opening shells, navigating the seafloor, and camouflaging.
57. Octopuses show problem-solving abilities and have been known to unscrew lids to get to food.
58. There’s a type of octopus known as the Star-sucker Pygmy Octopus which is one of the smallest species, reaching an arm span of only 10 cm.
59. Octopuses have been known to collect shells and other objects to create “gardens” around their lairs.
60. The ink of an octopus contains a compound called tyrosinase, which in addition to creating a smoke screen for escape, also messes up a predator’s sense of smell and taste.
61. The Greater Blue-ringed Octopus, one of the most venomous marine animals, changes colours dramatically when threatened.
62. Octopuses are believed to be colourblind, but they possibly interpret colour information from the polarization of light.
63. There’s a species of octopus known as the Football Octopus that blows itself up into a balloon-like shape to appear larger when threatened.
64. Female octopuses often eat their mates after copulation.
65. They can modify their RNA, a process not found in most other animals. This may explain their problem-solving abilities and adaptation skills.
66. Octopuses have a salivary papilla in their mouths that can drill through the shells of prey, allowing them to inject paralysing saliva.
67. Most octopuses are nocturnal and do their hunting at night.
68. Octopuses can detect pressure changes in the water with their lateral line system, a sense organ common to many aquatic vertebrates.
69. Some octopuses have an arm span as wide as 4.3 metres.
70. The common octopus (Octopus vulgaris) is found in every ocean.
71. The octopus’s lifespan varies between species. The Pacific Octopus can live for up to five years, while some smaller species may live for only a few months.
72. The ‘Octopus Wrestling’ was a popular sport in the mid-20th century, particularly in California. The practice has since been discouraged due to environmental and animal rights concerns.
73. The ability of octopuses to change colour is not just for camouflage. It’s also a way for them to communicate with each other.
74. Octopuses are known to sometimes engage in autophagy, or self-eating. Scientists believe this happens when the octopus is stressed or diseased.
75. In many cultures, octopuses are considered a culinary delicacy.
76. Some octopuses have been known to exhibit play behaviour, such as blowing bottles around in their tanks with a water jet.
77. The mimic octopus can not only change its colour but also take on the shape of other animals.
78. Each of an octopus’s arms has its own ‘mini-brain’ to control movement.
79. Male octopuses have a specialized arm called a hectocotylus, which they use to deliver sperm to the female.
80. Octopuses’ arms have a mind of their own. Even after being severed, the arms can still react to stimuli.
81. Some octopuses have been known to perform acrobatic tricks in exchange for food rewards, displaying their learning capabilities.
82. Octopuses can eject a cloud of ink when they feel threatened. This ink forms a dark cloud that obscures the octopus, allowing it to escape from predators.
83. Some species of octopus can regenerate their arms if they lose one.
84. Female octopuses sometimes blow gentle streams of water over their eggs to keep them clean and oxygenated.
85. When an octopus loses an arm, it can grow a new one within a few weeks.
86. A group of octopuses is called a consortium.
87. Octopuses have been observed opening childproof bottles, demonstrating their problem-solving skills.
88. Some species of octopuses can inflate themselves with water to appear larger and more threatening.
89. The eye of an octopus works in the same way as the human eye but, unlike humans, octopuses don’t have a blind spot.
90. There is a species of octopus, the Atlantic White-spotted Octopus, that can break off an arm when threatened. The arm continues to crawl away, distracting predators and giving the octopus a chance to escape.