Obvious Octopus Facts: How Many Tentacles Does An Octopus Have?

Akinwalere Olaleye
Oct 17, 2023 By Akinwalere Olaleye
Originally Published on Oct 22, 2021
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Common octopus under water.

An octopus is a scary-looking sea animal, especially with those tentacles which they use to bring food to their mouth.

The octopus is one of the most majestic creatures in the marine world. They belong to the group of cephalopods, which includes four members including squid and cuttlefish.

Are you a fan of octopuses? Compared to other sea animals, octopuses are unique in their appearance. This sea animal has tentacles that spread throughout its body. What exactly is the use of the tentacle? How many are there?

Octopuses are popular for their round body which consists of bulging eyes and eight long arms. They are seen in oceans but are abundant in numbers where there are warm, tropical waters. They have also been nicknamed ‘monsters of the deep', because they tend to stay deep down the ocean floor.

There are some species of octopus that stay on the surface of the water also. But, it is common for them to be deep under the ocean. Octopuses crawl around the ocean floor using their long arms.

The small openings seen in their sucker-covered tentacles are used to catch their prey. These octopus tentacles perform a variety of functions. It is also pretty scary to look at.

For those who are curious about these octopus tentacles, let's dive into the details. Afterward, do check out how do dolphins communicate and how big do angelfish get.

Why does an octopus have eight tentacles?

The octopus is classified as a cephalopod, along with other animals like squid and cuttlefish. Cephalopod refers to animals who have limbs attached to their head.

In this sense, the octopus is said to have eight tentacles. The eight limbs are commonly referred to as tentacles. Although now there are arguments on the fact whether all the limbs should be called tentacles or not.

The question of how many tentacles an octopus has becomes problematic once you go deep into the subject. Tentacles are said to have the ability to retract and only have suckers around their tips.

While an arm is shorter and has suckers all over it. Tentacles are also said to be in pairs.

In this sense, octopuses might only have arms and no tentacles. Whether we call them limbs, arms or tentacles doesn’t matter, these cephalopods do have eight of them.

The observations done on the octopus have revealed the fact that these sea animals use their tentacles to travel around the ocean floor. The back tentacles are used to push over sea rocks and other such things while the other tentacles carry them forward.

Do octopuses have arms or tentacles?

So, what do we call the eight limbs of octopus? Arms, tentacles? Studies suggest that octopuses have two legs and six arms. What is this classification based on? The eight tentacles of an octopus are divided into six arms and two legs. The legs function in movement while the arms help in the feeding process.

Octopuses are considered the world's most intelligent invertebrates. They can use tools with their sucker-filled tentacles. By careful observations, octopuses are seen performing 'arm' tasks with the first six tentacles and 'leg' tasks with the last two tentacles.

The basic functions are performed by the arms. Walking, hunting for food, manipulating objects, moving, tasting, sensing and so much more are done through these arms.

The majority of neurons that an octopus has are found in its arms. The arms are seen in coordination with the brain. There is no denying the fact that the majority of octopus tentacles perform the function of arms.

Octopus underwater close up portrait detail.

Does an octopus have bones?

The appearance of an octopus may bring out a doubt in us. Do these cephalopods have bones? No, they do not have bones. Octopuses are invertebrates. Which means they do not have bones. Animals that lack a vertebral column, spine, or other bones are called invertebrates.

There are different types of invertebrates. Insects, like snails, jellyfish, and worms along with animals in the cephalopod category like squid, cuttlefish, and octopus are all invertebrates. While being boneless may seem scary to humans, octopuses have many advantages as boneless animals.

They can squeeze into tiny spaces. Like a squid, these cephalopods are also extremely flexible and move their body in many ways. Their boneless bodies can hide in cracks and corners to catch their prey.

Since they are in the water, buoyancy plays a key role in their movement without bones. The strong muscles on their arms also help them move underwater. Being boneless is not even an issue for these creatures.

Do octopus tentacles grow back?

What happens when they lose an arm, do they live armless for the rest of their lives? Not exactly. Octopuses can actually grow back their tentacles. As soon as the arms are lost or damaged, a regrowth process starts to happen in the octopus.

Octopuses regrow their arms from the inner nerve bundles to the outer suckers. These intelligent creatures have a mini-brain in each arm. When an arm is damaged, the undifferentiated cells grow into stem cells and grow the arms back.

The new arms are just as perfect as the previous one and can perform all the functions effortlessly. This regeneration takes place in around 100-130 days.

The three main steps of regeneration of the arms are wound healing, regeneration, and renewal. The new arm will develop a mini-brain of its own for the new arm during the regeneration process. How cool is that!

The Seven Arm Octopus

The seven-arm octopus is the second-largest octopus species. As the name suggests, we can see only seven arms in this octopus. But what we see is not always what it is, right? Unlike the name, the seven-arm octopus has eight arms.

The male seven-arm octopus shows seven arms only. The eighth arm is coiled as a sac beneath its right eye. This hidden arm is mainly used for reproduction.

That is why their name implies the idea that seven-arm octopuses only have seven arms when in reality they have eight healthy arms. Unlike the male, the females of this species have eight visible arms. Apart from the hidden arm, all other characteristics and behaviors of males are similar to the normal octopus.

How many tentacles do squids have and what is the difference between these two?

While both squids and octopuses are cephalopods and invertebrates, there are many differences between both these species. The main difference is the number of limbs a squid has compared to an octopus. A squid has 10 limbs, out of which two are long tentacles and the other eight are arms.

Other than that, squids generally live in the open ocean while octopuses prefer the deep ocean floor. While a squid catches its prey using two tentacles and eats them in chunks, the octopus grabs their prey and pierce through the skin to inject paralyzing venom.

Octopuses are solitary animals who live alone except during the mating season. Meanwhile, squids can live independently or in groups.

Compared to squids, octopuses have a shorter lifespan. An octopus has an average lifespan of one to three years but a squid has an average lifespan of nine months to five years.

When it comes to appearance also, both these species are very different from each other. An octopus has a mantle, head, and eight arms, whereas a squid has a mantle, head, eight arms, and two tentacles.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for how many tentacles does an octopus have, then why not take a look at why do whales breach, or octopus facts.

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Written by Akinwalere Olaleye

Bachelor of Arts specializing in English Literature

Akinwalere Olaleye picture

Akinwalere OlaleyeBachelor of Arts specializing in English Literature

As a highly motivated, detail-oriented, and energetic individual, Olaleye's expertise lies in administrative and management operations. With extensive knowledge as an Editor and Communications Analyst, Olaleye excels in editing, writing, and media relations. Her commitment to upholding professional ethics and driving organizational growth sets her apart. She has a bachelor's degree in English Literature from the University of Benin, Edo State. 

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