Marine biologists have captured footage of a huge sixgill shark swimming off the coast of Ireland – marking the first time it's been filmed in shallow European waters.
The 13-foot-long 'prehistoric looking' sixgill shark (Hexanchus griseus) was discovered off County Clare on the west coast, at a relatively shallow depth of about 200 feet.
An apex predator, the sixgill shark typically inhabits dark waters off the continental shelf, at depths of up to 8,200 feet (2,500 metres).
It spends much of its time miles off-shore off the continental shelf and as a result has little interaction with humans – making this a rare sighting.
The shark gets its name from the fact that is has six gill slits, unlike most other sharks which have only five.
Researchers wouldn't disclose the exact location where it was filmed – only that it was seen off County Clare
The team of biologists, from Trinity College Dublin, Queen's University Belfast (QUB) and Belfast-based marine survey company Fjordstrong, filmed the specimen using modified 'Auto-Release Baited Underwater Video systems' (ABUVs) – patented fish-identifying video recorders.
The underwater footage shows the shark serenely swimming past the lens in front of a bait bag – a wire mesh full of chopped up and rancid mackerel.
'This was the first time sixgills have been filmed in shallow water in daylight in European waters, as far as we know,' Dr Patrick C. Collins, a lecturer in marine biology at QUB and member of the project, told MailOnline.
'They are normally regarded as a deep-water species.
'This highlights how Ireland is a biodiversity hotspot for all sharks, skates and rays.'
The experts used the bait bag to attract the shark, although it did not go for it and may have be lured by the lights, Dr Collins said.
'We observed a lot of smaller fish (wrasse, conger eels, ling and catsharks) feeding on the bait which may also have attracted the shark,' he said. 'It circled for a moment and then disappeared.'
Dr Collins said he is not able to disclose the exact location where it was filmed – only that it was seen off of caught off County Clare.
The team is only beginning to answer the mystery as to why sixgills are lurking off County Clare. They will expand their ocean exploration of this area over the next 18 months.
Pictured, the shark swims past the lens in front of a bait bag - a wire mesh full of chopped up rancid mackerel
'Sixgill sharks are an incredible species and this particular site off the Irish coastline is of particular interest as large, females have regularly been sighted in shallow waters,' said Haley Dolton, a biologist at Trinity College Dublin.
Sixgills in this location are mostly females, suggesting it is an important area for reproductive purposes, Dolton added.
'We are going to need a bigger boat to come back here next year and collect more data – we have only just scratched below the surface,' said Dr Collins.
Sixgill sharks can grow to 15 feet in length and weigh