Aussie teacher's wild encounter with deadly sea creature: 'It was so big'

Des Mellican was looking for starfish on a remote Queensland island when something 'beautiful' caught his eye.

A teacher has recalled his "fascinating" encounter with a deadly blue-ringed octopus after noticing "a blubber-like creature" near the rocks on a remote Queensland island.

Des Mellican, 50, has been working on Mornington Island, 28 kilometres off the coast of northern Australia, and was exploring the Gold Cliff area when suddenly a "beautiful" creature "as big as [his] hand" caught his eye.

"I was walking along the rocks just looking for starfish when I saw a blubber-like creature. Upon inspection, I identified it as an octopus," he told Yahoo News Australia.

However, the "penny didn't drop" quickly enough for Des who didn't realise it was a toxic blue-ringed species. "It was so big. I just thought there can't be a blue-ringed [octopus] that big".

Blue-ringed octopus Mornington island, Queensland
A blue-ringed octopus about 20cm in size was spotted on the remote Mornington Island in Far North Queensland. Source: Supplied
Gold Cliff, Mornington Island, Queensland.
A teacher was exploring the Gold Cliff area on the island when he discovered it. Source: Supplied

Larger than usual octopus: 'As big as my hand'

Typically just seven to 10 centimetres in size (or sometimes even smaller), this blue-ringed octopus was up to 20cm. "It was as big as my hand," said Des.

The species he stumbled upon was an "undescribed" species — not one of the current four types known— which is most common around the northern parts of Australia, octopus researcher Dr Julian Finn told Yahoo News Australia.

This other species is much larger than the typical blue-ringed octopus often seen along the east coast of Australia, including the southern blue-ringed octopus (maculosa) and the blue-lined octopus (fasciata). The same kind was spotted on a beach in Darwin this week, leaving Aussies stumped because of the larger size of the usually small marine animal.

Blue-ringed octopus found on sand on Mornington Island in Queensland.
The large octopus was almost white in colour with faint blue brings before it suddenly became more vibrant. Credit: Supplied
teacher Des Mellican on Mornington Island in Queensland.
Des Mellican, 50, was looking for starfish near the rocks when he discovered deadly creature. Source: Supplied

'Fascinating' moment after lethal encounter

It was only when Des sent a video and some photos to his friends he learned of his close encounter and was told he'd just discovered a lethal octopus. "I knew they were poisonous but I didn't really know what they looked like," he said. "I just thought it was a beautiful-looking creature. When someone said it was a blue-ringed octopus thought 'of course it is'.

Being from Brisbane, Des had never seen one before, but despite this, he said he was "cautious". Using a thong, he carefully guided the octopus back into the ocean — then something "amazing" happened.

"It turned bright orange," he recalled. Before that, the octopus was almost white with "faint blue rings' and nothing near as vibrant. "It was fascinating to watch."

Mornington Island in Queensland.
Mornington Island is a remote area in the Gulf of Carpentaria, north of Australia. Source: Supplied

Octopus changes colour when threatened, says expert

Dr Finn said this is pretty normal behaviour and happens when they are "startled" or feel "threatened". "If you see this display from a blue-ringed octopus, you are probably too close," he warned.

One photo shared with Yahoo shows the creature almost camouflaging with the sand. In another, it's a brighter orange with neon-like blue rings.

"When a blue-ringed octopus is out foraging, it will generally have a more subtle colouration, blending in with the environment, to avoid being seen by potential predators, and allowing it to sneak up on prey," Dr Finn explained.

The southern blue-ringed octopus (Hapalochlaena maculosa) (left) and the blue lined octopus (Hapalochlaena fasciata) (right) are two common species. Source: Google Images
The southern blue-ringed octopus (Hapalochlaena maculosa) (left) and the blue-lined octopus (Hapalochlaena fasciata) (right) are two common species. Source: Google Images
Gold Cliff area Mornington Island Queensland
The lesser-known species is commonly found in northern parts of Australia, including Mornington Island in Queensland. Credit: Supplied

But when it feels threatened, in this case by Des's thong, "it immediately responds with an aposematic display" — a display to repel predators, and in this case indicates that it's venomous.

"The blue-ringed octopus produces this display by relaxing the muscle around the blue rings, making more of each ring visible and darkening the area around the rings to create contrast. This species also turns orange," Dr Finn added

Thankfully, Des walked away unharmed with a story to tell and the octopus was safe too.

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