Sydney Aquarium's Blue Ringed Octopus

Sydney Aquarium currently houses the world’s most venomous octopus – the blue ringed octopus.

There are thought to be four species of Blue ringed octopus, three of which are found in Australian waters. The octopus on display is Hapalochlaena fasciata, and occurs in shallow waters from southern Queensland to southern New South Wales. This species can be found in Sydney harbour. Blue ringed octopus can be found amongst rocks, crevices and rockpools of sheltered inshore areas. They occupy the intertidal zone down to depths of 30 meters.

Blue ringed octopuses are a mottled yellowish-brown colour with dark brown bands and irregular faint blue circles and lines across the body. When threatened, these lines and rings become a vibrant blue colour.

Blue ringed octopuses are very small – rarely exceeding 15cm across outspread tentacles, and have a very short lifecycle. They reach maturity at four months of age, and generally live for only 1-1.5 years.

Blue ringed octopuses are very shy and are masters of camouflage. They generally will be found in small crevices, in shells, and underneath rocks in loose sand and rubble. They are able to change the colour and texture of their skin to match their surrounding environment exactly. This makes this animal extremely hard to find in the wild, and quite hard to spot on display here at the aquarium sometimes!

Venom

Blue ringed octopuses have powerful venom used for defense and for capturing prey. They feed primarily on small crabs, and occasionally on small fish and shrimp. The mouth of the octopus contains a beak like jaw. Prey is bitten, and the venom enters the wound as saliva, rather than being injected. The venom can also be released into the water around the prey item, paralyzing the prey.

The venom contains a neurotoxin called tetrodotoxin. This toxin is also found in other animals such as puffer fish, poison arrow frogs, some newts and salamanders, but the blue ringed octopus is the only animal that uses it in the form of venom. Tetrodotoxin is produced by bacteria that live in the salivary glands of the blue ringed octopus.

Tetrodotoxin shuts down signaling in nerves. The toxin interferes with the signals travelling from the brain to the muscles of the diaphragm and the chest wall and leads to respiratory failure. There is little or no effect of tetrodotoxin on the heart or brain.

One bite from a blue ringed octopus reportedly contains enough venom to kill 26 adult people!

Symptoms

People that have been bitten by a blue ringed octopus will feel numbness or tingling around the face and neck within a few minutes. This may be followed by difficulty in seeing, speaking and breathing. Victims may also experience vomiting, abdominal pain, weakness and lack of coordination. This progresses to paralysis which may last from four to twelve hours. If EAR (expired air resuscitation) is not given when breathing difficulty and paralysis begin, the victim will fall unconscious and die from a lack of oxygen to the brain. Death can occur within thirty minutes.

The victim may be completely paralysed and unable to respond, sometimes with fixed dilated pupils, but may still be aware of their surroundings, and have reported that they have been able to hear everything around them.

The symptoms can vary in severity, with children being most at risk because of their small body size. If the victim lives through the first 24 hours they generally go on to make a full recovery with no lasting side effects.

First Aid

Immediately apply a pressure immobilization bandage to the area of the bite. The bite is often painless and may go unnoticed by the victim. Reassure the victim, monitor their breathing and transport the victim to a hospital immediately. Perform mouth to mouth resuscitation if their breathing stops and continue until medical assistance is found. There is no antivenom available for tetrodotoxin.

Safety

The blue ringed octopus is the most venomous octopus in the world. It is a shy animal that only attacks when provoked. It is often found hiding in seashells and in rockpools. If one is found do not attempt to touch or move the animal.

To see our blue ringed octopus here at Sydney Aquarium, look for the wall tanks on the left-hand side, immediately after the Shark Nursery exhibit (formerly the Sydney Harbour tank).

🙂

Ever wondered if there is alien life out there? Well never-mind looking in outer space, we have some of the strangest, weirdest and positively alien creatures living right here on earth! To find them we must journey to inner space, the mysterious ocean world where earth’s very own alien species reside – the Octopus.

Now before you think they are not alien enough for you, let me tell you a little more about them. Firstly, octopus come from a class of animals known as cephalopods, a term formed from two Greek words, which literally means “head” and “foot”. This unusual name tells us about how these animals are constructed, basically with their foot coming straight off their head. Cephalopods include the octopus, squid, cuttlefish and the primitive nautilus.  There are over 700 discovered species of cephalopods living today and they are found in all the world’s oceans, from the tropics to the icy waters of the poles; and from coastal shores to the abyssal depths, some found as deep as 800m!

But of course you need more than that… 

Humans have red blood and all blood is red… right? Wrong, not with the octopus, these little aliens have green blood! The green colour is cause by the copper in their system, which they use instead of iron to aid them in transporting oxygen. Unfortunately copper is not as efficient as iron so the octopus compensates for this, with yet another alien feature – they have 3 hearts. 

Speaking of different colours; cephalopods can change colour faster than any other animal on the planet! With special colour changing cells called chromatophores which are linked to their nervous system, they can pulse and flash colours to confuse prey, dazzle predators and communicate emotions. Strangely, despite their amazing ability to change colour, most cephalopods are colour blind.

Cephalopods can also disappear before your very eyes! Using clouds of black ink and fast jet propulsion, octopus and their cousins can make a quick getaway. Some species even squirt the black ink out in a shape similar to themselves, to distract predators while they escape.

Still not alien enough for you? How about the belief that aliens are intelligent…?

Well, of course, so are our amazing cephalopods. Their intelligence has been the focus of much research over the years they are considered by many scientists to be the smartest invertebrate on the planet.  Octopus have been found capable of learning and have special parts of the brain dedicated to memory. They can solve complex puzzles and some have even puzzled their researchers in return, by creeping out of their tanks at night to steal fish from the adjacent tanks, then sneaking back into their tank to maintain their innocence the next morning. In fact octopus are so clever, they have not only 1 brain – or even 2 which would be amazing – but 9 brains! One central brain and one for each of their tentacles. Some recent research even suggests it may be possible that octopus can dream. Our octopus here at the aquarium has a whole box full of toys or food puzzles to continually challenge his brain, such as a glass jar which he has to learn to open to get his dinner.

Sadly, all these brains are very short lived, with octopus and their relatives living only a few short years. Most cephalopods have a lifespan of only 18 months, a few rare species living a lucky 4 years, but no longer. 

With all this in mind, don’t let all the strangeness of these earthly aliens scare you away from them, for they are one of the most endearing creatures you will ever meet. Each individual has their own unique personality but they are each of them just as loveable as the next.  Okay, so they don’t have fluffy fur, or big round eyes, but to shake hands with an octopus is an unforgettable experience! Whether you be having a water fight, playing tug of war, or just watching their curious antics it is indeed very hard not to love the octopus.  The more you learn about cephalopods, the more wondrous they become.

Behold Zorro – our resident alien

So, aliens on Earth…? You be the judge, come and visit “Zorro” our latest representative of the “other world” here at Sydney Aquarium.

Amy 🙂