Attack of the head-huggers
I HAVE BEEN FASCINATED by the blue-ringed octopus since I first encountered one as a young teenager.
Growing up in Sydney, Australia, I, like all kids, had been told never to touch any small octopus with blue rings at the beach. But snorkelling one day in a bay south of Sydney, I was in for a big surprise.
I was looking for crayfish and abalone, and diving to the bottom I picked up an empty abalone shell. Back on the surface I turned it over to get a better look, when suddenly something shot out of the shell – something tiny with bright blue rings!
Startled, I dropped the shell and backed away, thinking I was about to be attacked by this deadly creature. But the octopus followed me. In a panic, I backed away more, but it went on swimming towards me.
Thinking my life was in peril, I decided to put some distance been me and this little octopus, so kicked madly with my fins until I got back to shore. Back on land, my heart was pounding; I had survived my first encounter with a deadly blue-ringed octopus.
Years later, after learning to dive and seeing a number of blue-ringed octopuses, I realised how naïve I had been on that first encounter.
The octopus was not trying to attack me but, having been disturbed in its home, the poor thing was vulnerable and seeking shelter – and I was the closest shelter available.
BEAUTIFUL BUT DEADLY is the best way to describe the blue-ringed octopus family. Found only in the seas of the Indo-West Pacific region, four species have been described, with several more awaiting classification.
Most are less than 10cm long. They feed on crabs and shrimps, stunning their prey with venom delivered by biting. This venom is also toxic to humans, and at least three people have died from the bite of a blue-ringed octopus.
But the good news for divers who come into contact with these creatures occasionally at dive-sites in Australia and South-east Asia is that they are shy, non-aggressive and easily avoided. In fact, most don’t flash those vivid rings unless you annoy them. That’s a warning that they are venomous, so back off!
Over the years I have encountered a few blue-ringed octopuses and never had a problem with them. Even when annoyed, they prefer to flee.
They are also great photographic subjects, if you can find them.
I have been working on a book on muck-diving recently and, not happy with the blue-ringed octopus images I had on file, I set myself a goal of getting fresh ones, perhaps capturing some behaviour, such as feeding or hunting.
First stop was Sydney and Port Stephens to photograph the endemic New South Wales blue-lined octopus Hapalochlaena fasciata. While all blue-ringed octopus are nocturnal, this species is often found during the day.
Over a dozen dives I encountered three of these small octopuses strolling across the bottom. I got some nice new images, but didn’t capture any behaviour.
I moved on to Melbourne, and on a night dive at Blairgowrie Pier saw one southern blue-ringed octopus (Hapalochlaena maculosa). This endemic temperate species is found off Australia’s southern states but while I got some wonderful portraits, I observed no interesting behaviour.
Finally I headed to Lembeh in Indonesia, hoping to photograph the most common tropical species, the greater blue-ringed octopus (Hapalochlaena lunulata). No bigger than any other member of the family, its name comes from its larger rings.
Booking a week at the newly opened Cocotinos Lembeh Resort was fortuitous. Not only was it a great place to stay, but its dive-guide Iwan Muhani is one of the most experienced guides in Lembeh, and if he can’t find something for you, no one can.
I gave him a list, topped by the greater blue-ringed octopus. Iwan was confident, but did add that though they had been “everywhere” a few months before, he hadn’t seen one in weeks. This seasonal shortage had plagued me at other sites in South-east Asia.
AFTER THREE DAYS I was starting to think that this species was simply less common than other divers had told me. Iwan then suggested we dive Critter Hunt which, with its rubble bottom, was the perfect habitat. It’s the kind of site where you need a great guide, as all the best critters are hidden in the rubble.
Iwan quickly located a tiger shrimp, a hairy shrimp and a wonderpus. Then he hit the jackpot. I shot image after image of the pretty little greater blue-ringed octopus, which was barely 5cm long, as it slowly crept across the bottom.
After a few minutes I was happy to let it disappear under a rock, as I didn’t want to see it eaten by a hungry fish.
I looked up. Iwan was waving me over. He had found another one.
This one was a little angry at being disturbed, and flashing its rings. I got busy when Iwan suddenly appeared with yet another one sitting on his pointer. He then indicated for me to watch.
He gently placed the second octopus next to the first. Almost instantly, the first octopus leaped off the bottom and attacked the intruder, wrapping its arms around its head.
I was stunned. Was this a territorial fight, or a battle between rival males? I had seen fights between male cuttlefish and squid, but never octopuses. This was very strange behaviour.
I STARTED TO PHOTOGRAPH the pair, and suddenly realised that it was a very subdued fight. The larger octopus, on the bottom, didn’t seem too concerned about having the small one wrapped around its head, and was slowly walking across the bottom. I was baffled by the behaviour but keen to document it, so continued to shoot images.
After a few minutes the pair of head-hugging octopuses disappeared under a lump of coral. Iwan was going to get them out in the open again, but I had the images and didn’t want to disturb them any longer.
On surfacing I thanked Iwan and commented on the strange head-hugging fight. He laughed and said that they weren’t fighting, they were mating.
Suddenly the behaviour made perfect sense. I had been a naïve fool once again.
When octopuses mate, the male deposits a package of sperm into the female’s oviduct, using a modified tentacle. I have witnessed reef octopuses mating many times, with the male slowly sending out his arm to inseminate the female. With their very long arms, the mating couple could be several feet apart. However, blue-ringed octopus have very short arms, so the male has to hang onto the female to ensure the successful delivering of his sperm.
I SAW NO MORE greater blue-ringed octopuses in Lembeh, but only a month later I was in South Australia diving another great muck-site, Edithburgh Jetty. I was there to get more endemic species for my book, as this site has a great collection of cephalopods that emerge at night.
I quickly found the two species I was after, the strange southern sand octopus and the exquisite striped pyjama squid, but I was very surprised by the number of southern blue-ringed octopuses – they were everywhere.
Halfway through the dive, my torch highlighted another southern in the distance. I was about to ignore it to look for rarer species, when I realised that it had a lump on its head.
Moving in closer, I was amazed to see that it was a mating pair, in exactly the same position as the tropical species. For several minutes I photographed them as the female strolled across the bottom with the male embracing her head. They soon disappeared under a fallen pylon, but I felt privileged to have witnessed this rare event for a second time.
Later, reading up on the mating habits of blue-ringed octopuses, I was still thrilled but also felt a little sad, as this event signals the end of an octopus life.
Like all cephalopods, blue-ringed octopuses live for only one year and, after mating, the female lays her eggs, guards them until they hatch, then dies.
I’m sure I’ll encounter many more blue-ringed octopuses over the coming years, and only hope that I once more get to witness the strange head-hugging mating dance of these fascinating creatures.