Large glowing sharks discovered lurking in New Zealand waters

Source: 1News

Large sharks that glow in the dark can be found off New Zealand's east coast, scientists have discovered.

The deepsea kitefin shark, blackbelly lantern shark and southern lantern shark were all found to produce their own light, glowing blue.

They were found during a NIWA Tangaroa research voyage on the Chatham Rise last January.

Belgian marine biologist Jérôme Mallefet's research team joined the voyage in search of the glowing sharks.

He says their previous research on bioluminescent sharks is largely based on studying their corpses after death.

"They look at the skin of the fish and say, 'Oh, it has the tiny light organs, so it must be luminous'," he says

"So, I decided, we would take the opportunity to come to New Zealand and document them glowing." 

Scientists had previously identified these three shark species, but this is the first time they've been found to be luminous.

Marine biologist Jérôme Mallefet Mallefet, Belgium holding a black shark. Dr Mallefet was aboard a Tangaroa voyage to the Chatham Rise to document the luminous capabilities of some sharks in New Zealand waters.

The light is created by thousands of photophores — tiny light-emitting organs — in the outer layer of the shark's skin.

The photophores contain photocytes, which are cells with enzymes that catalyse to produce light.

It comes out as a blue glow.

"They are glowing in the dark. They are not producing flashes. They are glowing for a long time," Mallefet says.

They live in near-total darkness, in depths of more than 200m. 

The kitefin shark, which grows to around 1.8m long, is now confirmed as the largest known luminous vertebrae, the researchers say.

They believe the glow has multiple purposes, including counterillumination — a type of camouflage that works by producing light to match their silhouette to the sea above them.

Mallefet is hoping the team can come back and continue studying on the Chatham Rise.

He thinks there may be more luminous sharks lurking in New Zealand's waters.

"This first experimental study of three luminous shark species from New Zealand provides an insight into the diversity of shark bioluminescence and highlights the need for more research to help understand these unusual deep-sea inhabitants: the glowing sharks."

The research was recently published in the journal Frontiers in Marine Science .