A rarely seen baby ghost shark has been hauled up from the ocean's depths by a team of New Zealand scientists.
The ghost shark, which isn't actually a shark but a species of boneless fish called chimaera, was found in around 1.2 kilometres of water in an ocean-floor region called the Chatham Rise, during a research trawl off the South Island.
It is believed to have hatched just prior to being caught, according to fisheries scientist Brit Finucci — one of the scientists who made the discovery.
"It sat in the palm of my hand," said Dr Finucci, from New Zealand's National Institute of Water and Atmospheric Research (NIWA).
"It was about 10 centimetres long.
The larger species of ghost shark may reach up to 1.5 metres long, Dr Finucci said.
There are several known species of ghost shark, which, like real sharks, have a cartilaginous skeleton.
However, they're rarely seen because they typically live in the ocean's twilight zone beyond 200 metres deep.
The researchers, who made the discovery while surveying commercial fish stock numbers, have to do more work before they can identify which species they've caught.
"I've got some thoughts on what it might be, but we really won't be able to tell until we do some genetics on it, some analysis," Dr Finucci said.
Males have retractable sex organ on head
Dr Finucci has caught ghost sharks before during survey work, but this is the smallest she's seen.
Ghost sharks are thought to have diverged from real sharks about 400 million years ago, and today sit in a class called chondrichthyes with sharks, rays, skates and sawfish.
Among a number of unusual features, the males have a tentaculum — a retractable sex organ that protrudes from the head, according to Dr Finucci.
"They have these really sharp, calcified spikes on them and the thought is they use these to grab onto the female when mating."
But there are many things that are still unknown about these animals.
Because they're seen so rarely, Dr Finucci says any new discovery offers a chance to learn more about them.
"Every little bit helps us learn at what depths they're found, what they're eating, what eats them," he said.
"Really it's just that basic biology that we just don't understand for ghost sharks. So there's a lot to learn."
Some species are known to live well below 2,000 metres deep.
Ghost sharks are native to the south-western Pacific, mostly around Australia and New Zealand, and several species are only found here.
"[The waters around] New Zealand and Australia is a global hotspot for ghost sharks. A lot of them are endemic."
