A rare Longsnouted lancetfish has been found just offshore at Fitzroy beach in New Plymouth.

A rare Longsnouted lancetfish has been found just offshore at Fitzroy beach in New Plymouth.

The lancetfish is no Finding Nemo but one has been found a long way from home.

A lancetfish - usually found around 1000 metres deep - has been found just offshore at Fitzroy beach in New Plymouth.

Nik Pyselman was running with his friend Cam Twigley along Fitzroy beach on Wednesday evening when he saw an iridescent blue shape in the water.

Supplied Nik Pyselman (Left) and Cam Twigley found a rare Lancetfish while running on Fitzroy beach.

"It looked like it had been washed in and was sruggling to swim back out to sea," he said.

"I've heard of people catching them on long lines but I've never seen one myself."

"I've also heard them called cannibal fish before because they eat their own kind."

Pyselman took the fish to Keith Mawson of Egmont Seafoods who was able to identify the species as a longsnout lancetfish.

"They're generally caught in deep water over 1000 metres deep," Mawson said.

"It's very unusual to see one in this shallow."

Lancetfish grow up to about two-metres long and Mawson said the one found at Fitzroy was about 1.5 metres and was likely a mature specimen.

"One of the fishermen said it had a bit of damage on the tail which could suggest it had been in shallow waters before," he said.

"But it's hard to say whether the damage was from its latest excursion into shallow water or a time before."

"I've still got it in the chiller in case anyone needs to take any samples or photos."

Barry Govier said he had been a fisherman for more than 20 years but said he'd never seen a lancetfish.

"Fishermen usually catch them on the long line while fishing for tuna," he said.

"It could be the El Nino bringing in some unusual weather patterns."

"Were starting to see a lot of deep sea fish like bluefin tuna start to move in a bit closer."

The Ministry of Fisheries classify lancetfish as a by-catch species which have "little to no commercial value" and are often caught by fishermen seeking other pelagic - neither close to the bottom nor top - species.

While they are a rare find inshore 26,772 were caught by long line in 2009.