Northland house-sitters Alison and Graham Pickering were surprised at their discovery of a weird and wonderful sea creature while out fishing recently.

The couple, who are house-sitting in Tūtūkākā, were hoping to catch a few snapper or kahawai off the rocks at Te Waite Bay on November 23 when they made the rare find of an adult female argonaut.

They didn’t know that at the time, however. Their initial guess was that the mysterious creature was an octopus or squid that had made its home inside a beautiful nautilus shell.

It was nearly 10pm and the fishing “was not going well” when Graham spotted something in the water.

“I got a glimpse of an eyeball and thought it was a squid, but then it disappeared into the water column when I tried to reach it.”

When the Pickerings were packing up, Graham saw the creature appear again and waited as it washed in on the waves.

He grabbed it and the couple scrutinised its delicate spiral shell which had tentacles and suckers moving inside.

Graham tried calling his son, a marine biodiversity diver, to help identify their find but couldn’t get through.

Then the creature started coming out of its shell, and Graham could see hundreds of tiny eggs inside.

Though he initially wanted to keep the shell, thinking the octopus could easily find another home, he placed her gently back in the ocean knowing the creature had babies she was trying to protect.

Graham got a glimpse of an eyeball and initially thought the mysterious creature was a squid. Photo / Vet Around the World

It was only when they got home and the Pickerings did a bit of research, that they found out what it was – an argonaut, a type of octopus that makes its own shell to lay its eggs in.

“People rarely see them, but they come up at night and feed and during the day people never see them,” Graham said.

According to NZ Fishing and New Zealand Geographic, argonauts are more commonly known as the paper nautilus, and are a type of pelagic octopus that usually live far out at sea.

The females make ‘shells’, which are basically a paper-thin case to house their eggs.

It was only after some research that the Pickerings discovered they had found an argonaut. Photo / Vet Around the World

Alison, who took footage of their discovery and posted the video on YouTube, said it seemed to be rare to find a live argonaut inside the shell.

“It was pretty incredible,” Alison said.

“How amazing that we found a shell we thought was an ordinary octopus, and with a bit of research realised it was way more special than that.”

The couple have been back to the beach several times this week looking for any sign of the shell but have found nothing.

Even though they didn’t get to have the shell as a keepsake “we are happy to know she must be still out there somewhere with her babies,” Alison said.

Jenny Ling is a news reporter and features writer for the Northern Advocate. She has a special interest in covering health, food, lifestyle, business and animal welfare issues.