Octopuses are some of the strangest and most intelligent creatures in the ocean. With eight arms, three hearts, blue blood, remarkable camouflage abilities, and an unusually complex nervous system, they seem almost like animals from another world.
There are hundreds of octopus species, ranging from tiny species that can fit in a hand to enormous animals with arms stretching several meters.
Here are some amazing facts about octopuses that reveal just how extraordinary these animals are.
1. Octopuses Have Eight Arms
One of the most obvious features of an octopus is its eight arms.
Unlike human arms, octopus arms are extremely flexible and can bend, twist, and move in many directions.
Each arm is covered with hundreds of suckers that help the animal grip objects and explore its surroundings.
2. Their Suckers Are Extremely Sensitive
An octopus doesn’t simply use its suckers for holding things.
The suckers contain sensory receptors that help the animal detect touch and chemicals.
This means an octopus can gather information about its surroundings while physically exploring objects with its arms.
3. Octopuses Have Three Hearts
Octopuses have three hearts.
Two hearts pump blood toward the gills, where oxygen is absorbed.
The third heart pumps oxygenated blood around the rest of the body.
Interestingly, the main heart temporarily stops beating during swimming, which is one reason octopuses often prefer crawling rather than constantly swimming.
4. Their Blood Is Blue
Octopus blood is blue because it uses a copper-containing protein called hemocyanin to transport oxygen.
Hemocyanin works particularly well in cold, low-oxygen water.
This is very different from human blood, which uses iron-containing hemoglobin and appears red.
5. Octopuses Have a Large Nervous System
Octopuses have highly developed nervous systems for invertebrates.
A large portion of their neurons are located in their arms.
This allows their arms to process sensory information and perform complex movements with a remarkable degree of independence.
6. Their Arms Can Work Semi-Independently
An octopus doesn’t need to consciously control every movement of every arm.
Its nervous system allows the arms to perform many actions locally.
An arm can explore, manipulate objects, and respond to touch while the animal’s central brain handles broader decisions.
This distributed nervous system makes octopus intelligence very different from human intelligence.
7. Octopuses Are Excellent Problem Solvers
Octopuses are known for their ability to solve problems.
They can learn how to open containers, navigate obstacles, manipulate objects, and escape from enclosed spaces.
Their curiosity and flexibility make them some of the most impressive problem-solving animals in the ocean.
8. Some Octopuses Use Tools
One of the most famous examples of octopus intelligence is tool use.
Some octopuses have been observed carrying coconut shells or other objects and later using them as shelters.
This requires planning and the ability to recognize that an object can be useful later.