Octopi are extraordinary, unique creatures. Highly intelligent, able to blend into their surroundings, and capable of jet propulsion, there's more to octopi than eight arms.
1. Octopi have arms, not tentacles.
It is a common mistake to refer to an octopus' arms as tentacles. Tentacles are longer than arms. Tentacles usually have suckers only at their tips.
2. Octopi squirt ink to defend themselves.
Most species of octopusi can release a thick cloud of black ink that helps to confuse predators and provide the octopus an edge when attempting to escape. One of the pigments in the octopus' ink is melanin (the same pigment that gives our skin and hair color).
3. Special skin cells called chromatophores enable octopi to blend into their background.
Chromatophores enable an octopus to camouflage itself with its surroundings by changing the appearance of its epidermis.
4. There are three plural forms of the word octopus.
They include octopi, optopuses, and octopodes.
5. Octopi are cephalopods.
Cephalopods are a class of mollusc that includes squids, cuttlefish, nautilus, and octopi. Cephalopods are bilaterally symmetrical and have a head, arms, and in some cases, tentacles.
6. An octopus has three hearts.
Two hearts are used to pump blood to each of the octopus' lungs and the third pumps blood throughout the body.
7. Octopi have short lifespans.
Their lifespans vary among species but can be between six months and five years.
8. Octopi are highly intelligent.
They are believed to be the smartest of all invertebrates and show great skill at problem solving (instead of relying on instincts).
9. Octopi can fit into small crevaces.
Since they have no internal or external shell or bones, they can manipulate their body to fit into tight spots.
10. Octopi move through the water either by crawling or by jet propulsion.
When moving slowly, they crawl. If an octopus needs to get away in a hurry, it uses jet propulsion (by contracting their mantle and expelling a jet of water that propels them forward).
