Climate-adapting squid has scientists thrilled, puzzled

SAN FRANCISCO (KGO) -- A mysterious squid that lives along the Pacific coast could be one of the big winners in adapting to climate change. The squid is very large, very fast and very mean, but it's also willing to adapt.

The wild-looking animals are on the move with just two things on their mind: Finding food and making babies. The squid can get up to six feet long and weigh 100 pounds, and they are survivors.

"It can tolerate low oxygen," said Stanford Prof. William Gilly, Ph.D. "It can tolerate extreme temperatures, both cold and warm, and it can migrate wherever it wants. It's a very powerful swimmer."

Gilly is with Stanford University's Hopkins Marine Station and is an expert on Humboldt squid.


"They are sort of the ultimate predator," said Gilly.

In the middle of those tentacles, there is a razor-sharp beak.

"When it grabs food, it engulfs the food in the arm and brings it to up the mouth, then it probably just sits there like a little mincing machine," said Gilly.

Gilly knows that first hand: He was badly bitten by a squid a few years ago and has the scars to prove it.


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Transparent Octopus Goes Opaque in Blink of an Eye

Two deep-ocean species of cephalopod, an octopus and a squid, can go from transparent to opaque in the blink of an eye, a new study finds.

This impressive camouflage swap is an adaptation that likely keeps the cephalopods safe from two different types of predators. The first are deep-sea creatures that hunt by looking upward for prey silhouetted against the light filtering down through thousands of feet of water. The second are fish that spotlight prey in "biological" headlights. These fish use bioluminescence, their own body-driven light source, to hunt for food.

To avoid being seen as a dark silhouette, it pays to be transparent, said study researcher Sarah Zylinski, a postdoctoral scientist at Duke University in North Carolina. But when a bioluminescent light hits a transparent surface, the effect would be like a flashlight shining on a windowpane at night, Zylinski said: very reflective, and extremely obvious.

"Being pigmented is the best strategy at that point," Zylinski told LiveScience. The octopus and squid species essentially have the best of both worlds, she said: "Being able to switch very rapidly between the two enables you to optimize your camouflage."

Masters of disguise
Many octopus, squid, cuttlefish and other cephalopods have the ability to rapidly change colors to disguise themselves from predators. Some octopus species even mimic the shapes of various fish and other sea life.

But those are all shallow-water creatures. Zylinski and her colleagues wanted to look deeper, at animals that live about 2,000 to 3,000 feet (600 to 1,000 meters) below the ocean surface. There is little light at this depth, though enough light filters down so that sharp-eyed fish can swim below prey, peering upwards and look for shadowy silhouettes.

On board research vessels in both the Sea of Cortez and over the Peru-Chile trench, Zylinski waited for deep trawling nets to pull catches out of the water. The nets are raised with painstaking slowness, Zylinski said, so that the pressure and light changes are not so abrupt for the animals caught inside.

"It's a bit like Christmas, because you never know what you're going to get in the net," she said.

"Sometimes it's like that really bad Christmas where you don't get what you want, and sometimes it's really exciting."

Presto-chango
When Zylinski scored a cephalopod catch, she quickly moved the animals from the dark nets into a dark, cool room so as not to expose them to daylight or boat lights. Then she tried various methods of stimulating color changes.

"The first set of experiments I did, we were using the kinds of stimuli that I would expect to get a response from shallow animals," Zylinski said, including looming objects or shadows passing overhead.

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Light shed on bisexual and promiscuous deep-sea squid

Scientists have gained a rare glimpse into the sex life of the mysterious deep-sea squid.

By studying footage taken by underwater vehicles, US researchers have found that this rarely seen creature will often engage in same-sex mating.

They believe this is because encounters with potential mates in the dark depths are rare, and the squid may be unable to tell the sexes apart.

The study is published in the Royal Society journal Biology Letters.

The researchers looked at video footage taken over 20 years by Remotely Operated Vehicles (ROVs), most of which was recorded in the Monterey Submarine Canyon, off the coast of California.

The species that was observed is called Octopoteuthis deletron, a tentacled beast that measures about 12cm-long (5in), with impressive hook-lined arms. It was recorded between depths of 400m and 800m (1,300-2,600ft).

Until now, little was known about this creature's sex life, apart from the fact that the male uses a long, penis-like organ to deposit spermatophores, complex structures containing millions of sperm, onto a female, which are then absorbed into her tissue.

But by studying footage of this deep-sea squid, they were able to find out much more.

Indiscriminate insemination
Lead author Hendrik Hoving, from the Monterey Bay Aquarium Research Institute (MBARI), explained: "We did not observe two animals mating, but we found evidence of mating - sperm packages on males and females.

"Going through hours of video, we found that both males and females carry sperm packages.
"As the locations of sperm packages were similar in both sexes, we concluded that males mate with males and females."

The finding surprised the team, said Dr Hoving.

The researchers found equal numbers of female and male squid that had had sperm packages deposited on them, indicating that same-sex mating was as frequent as encounters between squid of the opposite sex.

The number of sperm packages that had been deposited also suggested that these animals were promiscuous, the researchers said.

This unusual behaviour, they said, may be explained by the fact the squid is boosting its chances of successfully passing on its genes in the challenging environment it lives in.

In the Royal Society paper the team writes: "In the deep, dark habitat where O. deletron lives, potential mates are few and far between.

"We suggest that same-sex mating behaviour by O. deletron is part of a reproductive strategy that maximises success by inducing males to indiscriminately and swiftly inseminate every [squid] that they encounter."

Following the study, the researchers now hope to use genetic techniques to determine the paternity of the sperm packages, so as to find out whether more than one male is trying to deposit its sperm on the males and females.
By Rebecca Morelle Science reporter, BBC News

http://www.bbc.co.uk/news/science-environment-14986769