Just when you thought it was safe to pull your catch from the water.
A spectacular photo believed to have been taken off Kaiteriteri Beach near Nelson proves it’s a shark-eat-shark world out there – and that you should always watch your tail.
The image, posted on social media site Reddit, shows a small school shark on the end of a fishing line being bitten into by a much larger blue shark just as it's about to be lifted into the boat.
Reddit user Mancubus uploaded the photo on December 28 with the headline: ''Caught a small shark … next minute''.
The picture quickly shot to the site's front page, garnering nearly 1000 comments before it was picked up by both the Daily Mail and Huffington Post news websites.
With few details available about what happened, readers were quick to guess what was going on, some believing the bigger shark was only trying to save its baby.
Others labelled the technique ''reverse fishing'', while a few said the photo had to be a fake.
Department of Conservation shark expert Clinton Duffy, a marine scientist, said the shot actually captured a common event.
''Blue sharks often steal fish off people's lines at this time of year and they also commonly eat other shark species.''
Duffy said the smaller shark was probably better known to New Zealanders as the white bit between the batter in their fish and chips – proving we're not the only ones partial to its taste.
The school shark, a juvenile, was likely about 80cm long while its bigger enemy was around 2 metres. Both were common species in New Zealand waters, although the blue shark was becoming a rarity due to the practice of shark-finning, Duffy said.
''It's quite encouraging really to see a picture like that,'' he said.
And if you’re wondering why the sharks have white eyes – Duffy says that's due to a special membrane that protects their eyes as they go in for the attack.
- © Fairfax NZ News