A Few Fun Octopus Facts

What is the plural of octopus?

The plural of octopus is octopuses. Or octopi. Or octopodes. Depending upon who you ask, lol! We do our best to walk you through the choices on deciding octopuses vs. octopi vs. octopodes in our post on the "correct" octopus plural.

How many hearts does an octopus have?

The octopus has three hearts! Octopuses have three hearts that serve slightly different purposes. The first heart circulates blood throughout the octopus's body, while the second and third hearts pump blood to the octopus's gills, picking up lots of oxygen.

Do octopuses have arms or tentacles?

Octopuses have arms. Octopuses have 8 appendages which are called arms, not tentacles. This is because, in anatomical terms, octopus arms have suckers running the length of the arm, whereas tentacles have suckers only at the ends.

Are octopuses smart?

Yes, the octopus is smart. Very, very smart. Octopuses are intelligent, have large brains for their body size, and can solve problems, unscrew jars to get food, and use tools. Octopuses also play, a behavior reserved for only a few extremely intelligent animals. Many researchers believe that octopuses may be as smart as dogs.

Can an octopus feel pain?

Yes, the octopus can feel pain. Science has established that octopuses do feel pain and try to avoid it. They will even seek out places that provide relief from pain. Not much different than us, huh? For that reason, we sincerely hope that people treat these animals the same way we would like our pets to be treated, or how we would like to be treated ourselves, when it comes to pain.

What color is octopus blood?

Octopus blood is blue, like that of many other invertebrate animals. Human blood is red due to the protein hemoglobin, which contains iron that binds to oxygen and carries it to our cells. The blue octopus blood uses copper instead of iron to carry oxygen, which is helpful when temperatures vary widely. Especially for octopuses who are found everywhere from the Caribbean to the Arctic circle. Unfortunately, this blue blood is highly sensitive to changes in pH, which may make octopuses particularly vulnerable to ocean acidification.

Is the octopus a fish?

No, the octopus is a cephalopod. Cephalopods are a type of mollusk and include creatures such as squid, octopuses, and cuttlefish. They are active and predatory, and are found in all the world's oceans at depths ranging from shallow coral reefs to the deep sea. They don’t have bones like most fish, but generally have large heads and eyes, and beak-like mouths. They also have arms or tentacles, which they use for locomotion and for catching prey.

Is the octopus dangerous?

Some octopuses are dangerous and can kill you, like the blue-ringed octopus. Most aren't particularly dangerous though! :)