Octopuses have beaks for mouths. The beak is located at the base of the arms, where the arms meet the mantle. The mouth is made out of chitin and is the only solid part of the octopus’ body. These beaks are used to break shells, eat chunks of flesh, and inject venom.
Octopuses are known for their jelly-like build and slithering tentacles. But did you know that they have a mouth?
This mouth works as a natural limiter: it determines the size of holes they can squeeze through.
In this article, we take a look at octopus beaks and elaborate on what they look like, why octopuses have them, and how are they used.
Do Octopuses Have Beaks?
Octopuses have beaks. They are made out of chitin and located at the base of the arms. They look like bird beaks and move in a scissor-like motion. Each octopus has one beak.
Octopus beaks are two-part, chitinous mouths: an upper and a lower part.
The lower beak is wider than the upper beak. It is embedded in extremely strong muscles to support a scissor-like cutting movement when biting.[1]
As they are made out of chitin, the beaks are solid. These are the only solid parts of octopuses, as they do not have bones. This is why octopuses can fit through any hole that their beaks can fit through.[2]
Where Is the Beak Located?
Octopuses have one beak at the base of their arms. The beak faces downwards. The beak is retracted when it’s not in use.[3]
What Do Octopus Beaks Look Like?
Octopus beaks look like parrot beaks. They have two parts, an upper and a lower beak. They are black, sharp, and softer at the base. It is embedded in muscular tissue.
The beak is made out of chitin, a cellulose-like polymer that is often found in invertebrates.[4] Although sharp, the octopus beak is short and stubby.
Rather than being long, it is curled, so it has a smaller surface to put pressure on. Octopuses do not need long beaks, as they raise their prey to their mouths with their arms.
Here are some of the key characteristics of octopus beaks:
- Curled
- Hard
- Sharp
- Black
- Chitinous
- Gets softer nearing the base of the beak
- Embedded in muscular tissue
- Two parts
- Upper beak is narrower and shorter than the lower beak
- They look akin to parrot beaks
Why Do Octopuses Have Beaks?
Octopuses have beaks for three main reasons: to break shells, to tear out chunks of flesh, and to deliver venom to their prey.
Octopuses are part of the class Cephalopoda, in which all members have beaks. This includes squids, nautiluses, and cuttlefish.
They evolved beaks mainly to suit their dietary needs. As such, octopuses use their beaks in the following manners:
- Breaking shells
- Eating
- Injecting venom
1. Breaking Shells
Octopuses mainly feed on animals with exoskeletons, so they need powerful beaks to break them down. They catch their prey with their arms, raise them to their mouths, and break their shells with powerful bites.
After the shell is broken, octopuses use their tongue-like organs called radulae to scrape the meat out of the shell.[5]
2. Eating
Octopuses do not chew their food. Instead, they dismember their prey into bite-sized chunks with their sharp beaks. While biting, they make scissor-like motions with their mouths.
As their beaks are relatively small, they do not hunt for larger animals. Instead, octopuses eat the following prey:
- Bivalves
- Snails
- Crustaceans
- Smaller fish
- Other octopuses
3. Injecting Venom
Octopuses have a venomous bite. They transmit their venom through their saliva, which they inject by biting.
Although their venom is a potent paralyzer, it usually isn’t enough to kill. The main usage of venom is to immobilize the target so the octopus can feed without much hassle.
Octopus Beak Size (Table?)
The size of octopus beaks varies between species. Beaks have four dimensions in which they are measured: upper hood length, upper crest length, lower hood length, and lower crest length.
As beaks are the only solid parts of the octopus, they are used when determining the size of dead individuals. If octopuses are eaten, their body is entirely digested, except for the undigestable beak.
Each octopus species has a different beak size. To give a better idea, the below table analyzes 90 Maori octopuses’ beaks size in relation to their full body size. The body size was deducted from the beak’s size.[6]
| Criteria | Measurement |
| Upper Hood Length | 0.087–0.51 in |
| Upper Crest Length | 0.33–1.73 in |
| Lower Hood Length | 0.07–0.38 in |
| Lower Crest Length | 0.17–0.89 in |
| Maori Octopus Size | Maximum of 6.56 ft |
Octopus Beak Compared to Other Species’ Mouths
Like octopuses, every other cephalopod has beaks. Apart from cephalopods, their mouths most closely resemble parrot beaks. Our mouths are nothing like octopuses’ mouths.
Octopuses and birds have beaks for similar reasons, although there are some other factors. While octopuses solely have beaks to support their diet, birds also developed beaks to hasten individual growth.[7]
The below table compares octopus beaks to other animal beaks. The human mouth is also compared to showcase how different octopuses are.
| Beak | Description |
| Octopus | Two parts, black, made out of chitin, embedded in strong muscle, retractable, softer at the base, toothless, curled, can’t chew |
| Squid | Akin to octopus beaks, generally bigger |
| Cuttlefish | Akin to octopus beaks, generally smaller |
| Nautilus | Akin to octopus beaks, generally the smallest of all cephalopods |
| Parrot | Two parts, generally black, made out of keratin, the upper beak is longer |
| Human (mouth) | Two jaws, tooth made out of bones, tooth coming out of gums, wider, bigger, can chew |
Conclusion
Octopuses have beaks. These are two-part, chitinous mouths embedded in strong muscles. They are located at the base of the arms. As the only solid parts of the octopus’ body, only these remain after the animal perished.
Octopuses have beaks to support their diet. They eat animals with exoskeletons, and they break their shells open with their beaks. They cut out bite-sized chunks to swallow, and they also inject venom with their bites. Octopus beaks are similar to parrot beaks.
FAQs
Do Octopuses Have Teeth?
No, octopuses do not have teeth. Instead, they have tongue-like organs called radula with many rows of chitinous, teeth-like structures called denticles. These are not teeth in the traditional sense, but they have a similar function: to cut and grind food.
Can an Octopus Eat a Shark?
Yes, although it’s unlikely. Octopuses normally hunt smaller prey so they can kill them easily. However, the largest octopuses, the giant Pacific octopuses are large enough to kill and eat smaller sharks.
What Is an Octopus Beak Called?
The octopus beak is called the “rostrum.” The word itself is Latin, literally meaning “beak.” It is not only used to refer to octopuses’ beaks but other cephalopods as well (squids, cuttlefish, nautilus).
