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How Big is an Octopus? Comparing the World’s Octopuses

Octopuses are some of the most intriguing and fascinating creatures on the planet, with its name literally meaning “eight legs” in Greek. With many different types of octopus out there in the world’s oceans, each species has its own interesting features and characteristics.

Octopuses come in all different shapes and sizes, not to mention their soft bodies that can help them to change shape and their nervous system that’s one of the most complex found amongst invertebrates. They are part of the cephalopod family, which makes them relatives of squid and cuttlefish.

However, what we really want to know is just how big can these creatures get? Let’s compare the different octopuses from around the world and find out!

How many species of octopus are there?

There are around 300 different species of octopus and they’re found in every ocean around the world. You’ll usually find octopuses on the seafloor, and they typically live alone, creating dens built from rocks to protect themselves. Sometimes they’ll even create a door for their den, pulling it close once inside!

Octopuses prefer warm, tropical waters and most species live in the deep, dark waters. Only a few are pelagic, which means they live closer to the surface.

What is the smallest octopus in the world?

While octopuses are usually known for their large size, there are some that are incredibly small. The smallest octopus in the world is the Wolfi octopus, also known as the star-sucker pygmy octopus. A Wolfi octopus weighs less than a gram and measures just over 1cm in length – which is smaller and lighter than a 1p coin! They don’t stray far from the coastline, living in waters above 30 metres, and are found in the Western Pacific Ocean.

Another tiny octopus is the common blanket octopus, also known as the violet blanket octopus (Tremoctopus violaceus). However, it’s only the males that remain tiny, as the females can grow up to 2 metres long! Male blanket octopuses typically measure around 2.3cm, making them around the same size as a walnut. They are particularly eye-catching as they have transparent webs that connect the arms. You’ll find this species out in the Atlantic and Pacific oceans.

The blue-ringed octopus (Hapalochlaena) is another very small species, but they are particularly deadly. A blue-ringed octopus can release a powerful neurotoxin called tetrodotoxin that can bring down 26 adults. Luckily, they tend to keep to themselves. This species is around 12cm long including its arms, and are found in the Pacific and Indian Oceans. This means the blue-ring octopus is ever so slightly smaller than the length of a £10 note.

What about the biggest octopus in the world?

The largest known octopus in the world is the Giant Pacific octopus (Enteroctopus dofleini), which has been known to grow as large as 30 feet (9 metres) across! However, the average size is typically around 5 metres, and weighing around 50kg. That’s about the same weight as a Great Dane. The Giant Pacific octopus, like some other species, can change colour to blend in with the surrounding plants and rocks when necessary. They hunt at night, feeding mostly on shrimp, lobsters and clams, but have been known to attack sharks.

Another large species is the Maori octopus, native to New Zealand and Australia. Dark red in colour with speckled white skin and uneven arms, the Maori octopus is particularly aggressive and even known to take part in cannibalism! On average, they weigh up to 12kg and a total length of around 1 metre. That’s around the same length as a standard guitar, and the weight of a French bulldog, or two average bowling balls.

The common octopus (Octopus vulgaris) can be classed as one of the world’s biggest octopus too! The common octopus is considered the most intelligent of all invertebrates, and can be found across different oceans – including off the south and west coasts of the UK! This species grows to around 1.3 metres long and can weigh up to 10kg. You can see the common octopus for yourself right here at Hastings Aquarium!

So, there you have it. Some of the world’s biggest and also tiniest octopus species known to man! Don’t forget you can check out more fascinating facts about these creatures, or buy your tickets and see our common octopus for yourself!

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