Sex trap for giant squid

A team of scientists from New Zealand is hoping to use sex to record the first ever images of a live giant squid.

Scientists have so far had to piece together clues from dead specimens

Marine biologist Dr Steve O'Shea is leading the group hoping to lure the huge cephalopod into view by taking advantage of what he believes is an annual migration of the animals to a particular area in New Zealand waters.

He thinks the female giant squid - like its cousin the cuttlefish - may secrete a sexual scent to attract a mate.

"We want to have several cameras suspended in the water column - maybe triggered by some sort of acoustic signal - such that when any animal comes into the range of the camera, the camera turns on," Dr O'Shea told BBC World Service's Discovery programme.

X-rated

"Because the animals are migrating into New Zealand waters to breed, they are very randy," the Auckland University of Technology researcher said.

"The freezer bag at home - to my wife's disgust - is actually full of giant squid gonad samples. We're going to grind all of this up, and we're going to have this puree coming out from the camera, squirting into the water.

"Hopefully the male giant squid, absolutely driven into a frenzy, is going to come up and try to mate with the camera.

"This is the dream - we're going to get this sensational footage of the giant squid trying to do obscene things with the camera."

TV competition

There is great competition developing between researchers - backed by television companies - to catch the first giant squid on camera.

No giant squid - also known as Architeuthis dux - has ever been caught in its natural habitat - the great depths under the ocean - as it only ever comes to the surface when dead or dying.

Indeed, scientists know more about the dinosaurs than they do about the huge cephalopod.

Giant squid can make up to 40% of a sperm whale's diet

"They're far enough away for it to be another planet for us," said Australian marine biologist Mark Norman, from the Museum of Victoria.

"We're talking 500 metres to probably 1.5 kilometres deep - very dark, very cold, very high pressure - not a particularly easy place for us to go looking around."

No one has ever seen the squid hunting, feeding or mating. Scientists do not know with any certainty how long it lives or how fast it can swim, although the suspicion is that the giant squid is not a fast pursuit predator.

"It's likely that the giant squid is hanging midwater," Dr Norman said.

"They effectively use the chemicals out of their urine to make ammonia solution that they put in little pockets all through their muscles.

"That makes them float, because the ammonia is more buoyant than seawater."

This was a common feature among deep sea animals, Dr Norman said, because it could be two or three months between feeds and the squid had to expend as little energy as possible.

Hunter hunted

The giant squid consists of a head, the mantle - which is the main body, and houses the intestines of the animal - and eight arms, together with two tentacles with clubbed, toothed ends that are used to grasp large fish.

In total, it extends 18 metres and weighs a quarter of a tonne. But despite its size, the squid may itself sometimes be the prey.

"In certain parts of the world, they're probably making up to 30 or 40% of the diet of sperm whales," Martin Collins, a specialist in cephalopods at the British Antarctic Survey, said.

Australasia is where most giant squid have been found

This evidence has already inspired one filming technique.

"Sperm whales don't seem to have a problem finding them, and that idea is behind some of the technology film crews have tried," Dr Norman said.

"[The crews were] sticking cameras on the heads of whales and calling them SpermCams. When the lights came on, they hoped the cameras would catch the giant squid in the headlights.

"But all that seemed to happen was the sperm whales got enormously frustrated by these things suction-cupped on the sides of their heads."

Dr O'Shea hopes that if his method works, it will add substantially to our knowledge of these amazing creatures and how they mate.

Scientists were intrigued when they found the first ever mated female with her skin still intact. Along the length of the female's arms were small holes, beneath which were a number of worm-like sperm chords radiating outwards.

Male giant squid have been found to have a long, muscular penis, which is unusual as the males of most other squid species use an arm to pass sperm packets from themselves to the female.

'Hypodermic penis'

Scientists believe that the male squid literally injects his sperm into the female's skin during mating.

"The two of them mount beak to beak, so you've got arms and tentacles flying everywhere," Dr O'Shea said.

"The male is co-ordinating this enormous penis, and he's implanting spermadaphores into the female's arms.

Some giant squid have occasionally been caught by fishermen

"He uses the penis like a plunger or a huge hypodermic needle, and he's physically stabbing the female's arms."

The females then store the sperm in their bodies until they are ready to lay eggs.

A huge mass of jelly and eggs are released from the mantle in amongst the female's arms - but no one really knows what happens from that point on.

"Either the skin starts rotting and the sperm gets exposed, or the sperm comes to the surface on hormonal cues, or the female may even physically open the skin up herself with her beak or her suckers," Dr Norman said.

"Somehow she gets the sperm to the eggs as she ejects a large gelatinous mass of jelly and eggs."