Octopuses are one of the most intriguing and ancient creatures in the ocean, with around 300 known species. The oldest discovered octopus fossil comes from a specimen that lived approximately 296 million years ago.
They are among the most intelligent animal species on the planet and one of the few capable of camouflage and full limb regeneration. Octopuses belong to the Cephalopoda family, alongside squids and cuttlefish. Scientists have long been fascinated by their alien-like appearance and unique characteristics, which we will explore in this article.
Physical characteristics and defense mechanisms
One of the first noticeable features of octopuses is their unique appearance. Their body consists of a head and eight arms, which are covered with suction cups on the underside. Each arm contains around 200 suction cups, which they use for hunting and movement. These suction cups are so sensitive that they also serve as sensory organs for taste and touch. Interestingly, two-thirds of an octopus’s neurons are located in its arms, which scientists believe act somewhat independently as if each had its own “mind.” This allows octopuses to use two or three arms for one task while the others perform different actions simultaneously. They can also fully regenerate lost limbs.
Octopuses have no bones or protective shells, allowing them to squeeze through the narrowest spaces to escape predators, making them excellent stealth hunters. The only hard part of their body is the “beak,” located at the center where all arms converge.
Another defense mechanism they use against predators is their ink, which they release when threatened. This ink temporarily disorients the predator, dulling its sense of taste and smell, giving the octopus enough time to escape or hide.
One of the most remarkable characteristics of octopuses is their skin. Besides having the full ability to change colors—similar to chameleons and some other species—they can also alter the texture and shape of their skin within seconds. This allows them to convincingly mimic corals, rocks, and other ocean floor surfaces. They can even imitate the appearance of more dangerous animals to deter predators.
The smallest octopus species is Octopus Wolfi, which grows up to 2.5 cm and weighs just 1 gram. In contrast, the largest species, Enteroctopus dofleini (the Giant Pacific Octopus), can reach an incredible 5 meters in diameter and weigh up to 50 kg. According to National Geographic, the largest recorded octopus weighed 272 kg and had a diameter of 9.1 meters.
Intelligence
The incredible intelligence of octopuses continues to astonish scientists, particularly because their cognitive abilities evolved in a completely different way than human intelligence. They are considered one of the most intelligent animal species on Earth and are among the few that have been observed using tools—a sign of advanced problem-solving skills.
Octopuses have a total of nine brains: one central brain in the head and a smaller brain in each arm. As mentioned earlier, this allows their arms to act independently, giving them remarkable multitasking abilities.
They excel at solving puzzles and are known for their ability to escape from aquariums. Octopuses can open jars from the inside to free themselves and untie complex knots. Some researchers even speculate that octopuses might have been among the first intelligent beings on our planet.
Blue blood and three hearts
Octopuses have blue blood due to a copper-based protein called hemocyanin. This protein helps transport oxygen in cold, low-oxygen environments.
Their three hearts serve different functions: one pumps blood to the organs, while the other two pump blood to the gills. When an octopus swims, the heart supplying blood to the organs temporarily stops, which is believed to be the reason octopuses prefer spending most of their time on the ocean floor.
Lifespan, reproduction, and diet
The lifespan of an octopus depends on the species. Some live for only about six months, while larger species can live up to five years.
Octopuses are mostly solitary and only interact with others of their kind during mating. However, some species exhibit more social behavior than others.
Reproduction is fatal for octopuses. Mating occurs when the male uses a specialized arm called the hectocotylus to transfer sperm into the female’s mantle cavity. Females can lay up to 350,000 eggs, but after they hatch, the mother’s body undergoes cellular breakdown, leading to her death. Males also die shortly after mating.
Octopuses primarily feed on small marine creatures such as shellfish, crabs, and fish. Baby octopuses live in plankton clouds and feed on larvae of other animals until they mature. Some octopus species that live closer to the surface have even been observed preying on birds.
Octopuses are undoubtedly one of the most fascinating creatures on Earth. Their intelligence, biology, and physiology make them a subject of great interest for scientists and ocean lovers alike. Every characteristic they possess is more intriguing than the last, making them one of the greatest mysteries and marvels of the ocean—and the planet.
