Octopus Ink: What Does it Do?

A few years back, we explored the the mechanics of how octopus inking works. To recap, octopuses have an ink sac located near their digestive system, and when necessary, they can eject ink out of the sac accompanied by a burst of water to serve as a smokescreen to confuse predators while the octopus swims away.

Octopuses have two main methods of inking. The first type is the one with which we are most familiar. The octopus will squirt a large cloud of ink, then make a quick getaway, leaving behind a predator befuddled by the inky smokescreen. Sometimes though, the octopus will release several small clouds of ink approximately the same size as the octopus itself meant to be pseudomorphs or "false bodies" that serve as decoys to confuse the predator. What's interesting is that the composition of these smaller ink "bodies" differs from that of one large ink cloud as they contain greater amounts of mucus, thereby allowing them to hold their form longer while the octopus - or cephalopod - escapes.

This method, commonly referred to as "blanch-ink-jet maneuver", is so effective a variety of species have been witnessed attacking the false bodies.

Wait - it gets better! There is some evidence to suggest that certain chemical compounds found in octopus ink actually suppress or disable certain predators' chemosensory systems, leading scientists to believe that octopus ink is much more than a mere smokescreen.

Cephalopod ink has been shown to contain several chemicals with some varieties depending on the species. The primary components are melanin and mucus. Tyrosinase, dopamine and L-DOPA, and small amounts of amino acids, including taurine, aspartic acid, glutamic acid, alanine and lysine are also known constituents of octopus ink.

While there is still much research to be done, recent evidence suggests that cephalopod ink is toxic to tumor cells.

We have a long way to go to uncover the many mysteries shrouding the octopus, so please join us as we continue to explore and celebrate everything octopus.

What Does the Octopus Tell us About Climate Change?

Originally posted June 12, 2012
Written by Deb Anderson
TheAge.co.au

Octopuses help us understand our world - past, present, and future - yet another reason to love these fascinating cephalopods! Check out this interesting interview with geneticist, Jan Strugnell, to learn what the octopus can tell us about the planet.


AN ANTARCTIC octopus has given scientists a clue to the risk of catastrophic sea-level rise if world temperatures keep climbing. La Trobe University geneticist Jan Strugnell and an international team analysed the genes of the Turquet's octopus, which lives in the Southern Ocean, as part of the first Census of Antarctic Marine Life (a 10-year project involving about 2700 experts from 82 nations). Dr Strugnell says scientists now have the largest sample sizes ever collected from Antarctica and this finding shows their climate concerns could be justified.

What led you to study the genes of a relatively sedentary Antarctic octopus?

We were interested in investigating patterns of connectivity around Antarctica in a marine species and we wanted to try to get a picture of what the past environment was like. We wanted to see what factors have influenced the evolution of this species and if the octopus contained genetic signatures of the past environmental conditions.

Why this creature — what makes it so special?

The Turquet's octopus is an ideal choice as it presents in large populations and is found all around the Southern Ocean. This octopus also lays relatively few, large eggs — between 22 and 60 eggs, each about 20 millimetres long — and they hatch into little octopus that live on the sea floor close to their parents, ie, they don't have a planktonic larval phase like most octopus.

And this has implications for genetic research?

This means there isn't as much genetic mixing between populations as there is in a species with a planktonic phase, so each population can develop different signatures across generations if they have been separated for a long time.

Your work must involve incredible fieldwork?

Yes. I've been lucky enough to travel to the Southern Ocean twice to catch octopus — once to locations around the Antarctic Peninsula and a second time to the Amundsen Sea [in western Antarctica]. The trips are for a few months at a time. The scenery is very beautiful and the ice is surprisingly colourful.

How on earth do you keep warm?

Life on research ships is very comfortable and warm inside. Working on the deck can get pretty cold, though — and you definitely need multiple pairs of gloves to stop your fingers freezing.

This research was part of a census?

Yes. The Census of Antarctic Marine Life and the International Polar Year really facilitated sharing samples between different countries and organisations, which made this study possible.

And this study, how did you do it?

We sampled 450 individuals of Turquet's octopus from locations all around the Southern Ocean. I genotyped 10 microsatellite loci — fast-evolving population genetic markers, and I also sequenced cytochrome oxidase I — the "barcoding gene" — from each of these octopus. We used this data to look for similarities and differences in the genetic signatures of octopus sampled from populations around the Southern Ocean.

What did you discover?

We expected we would find a marked difference between octopus populations separated by large distances. However, the genetic signatures of populations in the Ross Sea and the Weddell Sea — on opposite sides of Antarctica, separated by about 10,000 kilometres — are startlingly similar.

Can you explain the significance of that?

This is an interesting finding because it supports some climate models that suggest sometime during the last 1.1 million years there has been a collapse of the West Antarctic Ice Sheet. This would have raised the global sea level by 3.3 metres to five metres, and created a seaway across West Antarctica between the Ross and Weddell seas, potentially allowing exchange of animals between these seaways. The genetic similarity we see in octopus from the Ross and Weddell seaways supports this idea of a historic seaway.

What does this tell us about the years ahead?

This has implications for the future as some scenarios of future climate change predict such a collapse during the next two centuries, which would again open this seaway and permit genetic exchange between these regions.

Read more: TheAge.co.uk

128 Million-Year-Old Fossil Ancestor of Squids & Octopus Found

Originally from PressTV.com

LONDON: Scientists have unearthed the fossils of a 128-million-year-old spiky creature which they say could be the oldest ancestor of the modern-day squid and octopus. Using 3D scanning technology , a team from the Austria National History Museum unearthed the fossil of the creature, called Dissimilites intermedius, a layer at a time, and then created a video of how the creature lived and moved.


The ammonite was discovered in sediment which formed at the bottom of the ocean during the Cretaceous period some 128 million years ago, but now lies at the top of the Dolomite mountains in the Alps.

The scientists said that the computer tomography had allowed them to see far more than they would ever have been able to with the naked eyewith the creature exposed a layer at a time. The team, led by Alexander Lukeneder , also discovered that the body was covered with spines each between three and 4mm long. "Computer tomography and a 3D reconstruction programme were used to help reconstruct not only the appearance of the fossil, but also to work out how it moved." The spokesman added that prehistoric Tethys Ocean, which existed between the continents of Gondwana and Laurasiam, had left behind millions of years-worth of sediment at the bottom of the sea.

Gondwana would break up to form much of the southern hemisphere, and Laurasia would form much of the northern hemisphere. As the centuries passed and the Alps folded out of the sea, some of the former sea-bottom sediment ended up on the peaks of the Dolomites. And it was here that a section of the former seabed was discovered - with the thickest density of fossils.

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Check out PressTV.com for pictures.

Scientists Create Robot Octopus Arm

A soft-bodied robotic octopus arm has been created by Italian scientists. The waterproof limb is designed to mimic an octopus appendage as a model for underwater rescue robots of the future.

It's part of a project to create a full-bodied synthetic sea creature which could be used to save people trapped underwater. Check it out!

Polarized Display Sheds Light on Octopus and Cuttlefish Vision – and Camouflage

Written by Katherine Harmon
Originally posted on blogs.scientificamerican.com on February 20, 2012

Octopuses are purportedly colorblind, but they can discern one thing that we can’t: polarized light. This extra visual realm might give them a leg (er, arm) up on some of the competition.

And a team of researchers has created a new way to test just how sensitive cephalopods are to this type of light. Their results were published online Monday in Current Biology.

“We now know that polarization is tuned much more finely than we thought it was,” says Shelby Temple, of the Ecology of Vision Laboratory at the University of Bristol in the U.K., who led the study.

Image courtesy of Shelby Temple
But testing polarized light is tricky, especially since we humans aren’t tuned to see it. As Temple and his co-authors wrote in their paper: “For animals that can see it, the polarization of light adds another dimension to vision, analogous to adding color to a black and white image.” Polarized light is different from what we see in that it comes from a single angle, and animals that can detect it seem to see it in different resolutions based on changes in its angle. (The closest we can get to using it is putting on a pair of polarized lenses to cut down on glare.)

Polarized light perception in the best-tuned animals was assumed to be limited to differences of about 10 to 20 degrees. But in the group’s new experiments, the mourning cuttlefish (Sepia plangon) responded to just 1.05-degrees change of polarized light orientation.

For the experiments, the team used computer screens that had had the polarizing light filter removed (without these front filters on our liquid crystal displays—LCDs—our monitors would project polarized light images that we wouldn’t be able to see).

These modified displays played digital movie versions of “looming stimuli” such as an expanding circle, which would suggest a potential predator approaching. But instead of a color or intensity-based image, the one they created was based on changing polarized light orientation only.

Image courtesy of Shelby Temple
Octopus don’t yet seem to be quite as sensitive as cuttlefish to the fine gradients in polarized light, responding only after about 10 degrees shift. But, says Temple, “it may be the way that we’re testing.” As he points out, cuttlefish’s knee-jerk response to an approaching predator is a quick change of color, which the researchers could use as an indication that they had seen even fine shifts in the polarized light angle.

“Cuttlefish, they wear their emotions on their sleeve, quite literally,” Temple says. “They’re showing everything that they’re doing as a neural response.” In fact, the cuttlefish responded so well, that he and his colleagues thought they were doing something wrong. They were afraid that in the digital renderings they might have accidentally included a non-polarized light clue, such as brightness or intensity. But they went back and checked and found that it was, indeed, just the slight change in polarized light that was frightening the animals.

With octopus, “there’s no comparison,” he says. But, he concedes that it is possible that the octopuses might have seen finer resolutions of polarized light shift but just didn’t have the same simple, speedy reaction as the cuttlefish.

And says Temple, “it could be that some species could do it better than others.” So far, he has found that the blue ringed octopus looks to me more sensitive than the day octopus. He has plans to test different species of octopus soon.

Researchers are still working to get to the bottom of cephalopod vision, which is turning out to be highly complex. And this new work supports the idea that such sensitivity to polarized light emerged precisely because these animals don’t see color well—if at all.

Image courtesy of Shelby Temple
And if octopuses, cuttlefish and squid—and some of their predators and prey—can see polarized light so keenly, are they also using it, as they use color and luminosity, to actively create camouflage?

Other researchers are working on that very question. And Temple and his colleagues have observed that, at least in some cuttlefish, they can create a polarized light-based pattern on their skin. This play in light might “be used as part of a covert communication channel, invisible to animals lacking polarized vision,” they wrote.

But the patterns remain tricky for us to pick up on. For that, Temple and his colleagues have developed a way for us to get a peak into the invisible world of polarized light and dark by modifying a digital single-reflex lens (SLR) camera and creating a computer program to feed false-color into varying degrees of polarized light. These mysterious rainbow-colored ecosystem images make it clear that, “We’re not done with the story yet, for sure,” Temple says.

Pale Octopus, Hairy-chested Yeti Crab and Other New Species Found

Scientists exploring underwater vents near Antarctica find a world of creatures thriving in temperatures of 400C

Alok Jha

guardian.co.uk, Wednesday 4 January 2012

A world of previously unseen creatures has been found thriving next to boiling vents of water, several miles under the surface of the Southern Ocean near Antarctica. Hundreds of hairy-chested yeti crabs, a mysterious-looking pale octopus and colonies of limpets, snails and barnacles were found by British scientists at a hydrothermal vent located in the ocean's East Scotia Ridge.

Prof Alex Rogers of Oxford University used a remotely operated vehicle called Isis to scout the sea bed around the ridge, which spans about 2.4km and features springs of black, smoky water that can reach temperatures of almost 400C (752F). The hydrothermal vents are powered by underwater volcanoes, and the scalding temperatures and rich mineral content of the water gives rise to vast rocky chimneys that support a wide variety of life forms.

An image of some of the thriving life found beneath the Southern Ocean. Photograph: Oxford University/PA "The visually dominant species are the yeti crabs, which occur in fantastically high densities, up to 600 per square metre around the southern ridge," said Rogers, who led the expedition aboard the RSS James Cook in January 2010. "Also high densities of stalked barnacles, a large snail from a group called the peltospiroids, and we've also got small, green limpets which occur all over the vents."

The first-known yeti crab, Kiwa hirsuta, was described living near a hydrothermal vent in the south pacific in 2005 and, since then, several species have been discovered in different parts of the undersea world. Around other hydrothermal vents, however, these creatures tend occur in lower numbers; and the new species found in the ESR are not only more numerous but also visually distinct.

"Hirsuta has long hairs on its limbs and its claws, whereas our yeti crabs have extremely hairy chests. One of the nicknames of the crabs which developed during the cruise was the Hasselhoff crabs because they had these dense mats of [hair] on their undersides, the equivalents of their chests."

Another striking creature spotted by the scientists was a pale octopus, which was photographed by the team. Rogers suspected it might be a new species related to the Vulcanoctopus hydrothermalis seen at other underwater vents around the world.

In total, the expedition brought back more than 12,000 samples of rocks, bacteria and animals. Rogers said: "One of the staggering things we did find is that these vents are completely different to those seen anywhere else – the animals existing at these vents are almost all new to science," he said. The findings were published on Tuesday in the journal PLoS Biology.

"What we didn't find is almost as surprising as what we did," said Rogers. "Many animals such as tubeworms, vent mussels, vent crabs, and vent shrimps, which are found in hydrothermal vents in the Pacific, Atlantic, and Indian Oceans, simply weren't there."

Last week, scientists at the University of Southampton announced the discovery of new creatures in the so-called "Dragon Vent" in the south-west Indian Ocean.

Dr Jon Copley, a marine biologist at the University of Southampton who led the exploration of the Dragon Vent and is also an author on the latest PLoS Biology research paper, said that exploration of the world's deep-sea vents was a race against time.

"The exploitation of the deep ocean is overtaking its exploration. We're fishing in deeper and deeper waters, oil and gas is moving into deeper waters and now there's mining starting to take place in deep waters. We need to understand how species disperse and evolve in the deep oceans if we're going to make responsible decisions about managing their resources."

Rogers added that the vents revealed much about how deep water communities have evolved, and how they are distributed across the world's oceans. "In the space of a single eight-week cruise, we've changed our level of understanding of these systems completely. We've changed our ideas about how vent systems are distributed and the factors that may influence that distribution. What that tells us is that our level of knowledge of the deep sea in general is extremely poor indeed."

He added that hydrothermal vents had already changed the way scientists thought about how life exists on earth. "They told scientists that life could exist in the absence of sunlight – you could have food webs based on mechanical energy. They were also informative about the extreme conditions under which life could exist, they told us about where else in the universe life may occur. Hydrothermal vent biology has stimulated a whole new science of astrobiology."

Octopuses Capable of Hand-Eye Coordination

By Helen Albert, CosmosMagazine.com
May 30, 2011

LONDON: Octopuses are able to use visual cues to guide a single arm to a location, a complex movement that was not thought possible due to their lack of a rigid body structure, say researchers.

The octopus' arm is made up primarily of muscle with no skeletal support, so octopuses were previously believed to have a low level of body awareness and only limited control over their limbs. However, this study has shown for the first time that they can direct a single arm in a complex movement to a target location.

"Octopuses have a central nervous system that is advanced for an invertebrate, but simple compared to a vertebrate, yet it is capable of controlling a much more 'difficult' arm," said lead study author Tamar Gutnick, a researcher at the Hebrew University of Jerusalem in Israel.

"Because of the unique body plan of the octopus its ability to control a single arm in a complex movement is quite amazing."

Too soft for complex movement?

Octopuses were thought to have no conscious central nervous system-directed (CNS) control over their arms with movement being controlled solely by the activity in the complex array of nerves (PNS) present in the limbs.

However, the visual aspect of the task carried out by the octopuses in this study suggests that there must be an exchange of information between the CNS and the PNS during such behaviours.

Photo by Tamar Gutnick
In Gutnick and colleagues' experiment, six out of seven octopuses succeeded in using a single arm to select a visually marked compartment containing a food reward in a three-choice, plexiglass maze.

The animals were required to reach the compartment containing the food reward at least five times in a row out of a total number of trials ranging from 61 to 211. The octopuses could only use one arm to complete the task, as the tube leading to each compartment was only wide enough for one limb.

How brains control behaviour

The team observed that the chance of a successful trial improved significantly during the last 20 trials for each animal compared with the preceding trials.

They also noted that the animals seemed to learn that they needed to see the three boxes to improve their chances of getting the reward and were significantly more likely to be in view of the boxes during the last 20 trials than during the earlier tests.

The octopuses also adapted their arm use strategy from mostly 'straight', involving a direct unrolling or pushing upwards of the arm through the tube, to a 'search' strategy, involving probing and crawling in the central tube and above the choice boxes before deciding on a compartment.

Photo by Michael Kuba
It's not automatic

"This is a very important step in our knowledge of octopus behaviour," commented Jennifer Mather, a professor of psychology and expert on octopus behaviour at Lethbridge University in Alberta, Canada.

"The octopus has a large number of complex arms, and the question of how they manage to guide all of them is a fascinating one. We had previously thought that it might be fairly automatic or that their control was more at the local level within the arm. This is good evidence that local control need not be all," she added.

Studies involving octopus motor control, such as this, are the foundation of a current European Union research project to develop a robot octopus (Octopus Project). The aim of the project is to design and produce a soft-bodied robot that moves and squeezes through narrow spaces in a similar way to a biological octopus.

"Depending on the size of the robot its use could be from medicine (constructing new soft-bodied ultra flexible surgical tools) to big robots that could be used in search and rescue," said Gutnick, who is continuing her research on motor control.

"We are continuing to look at single arm tasks where animals are taught using a variety of senses, exploring the involvement of central and peripheral information," she said.

Noise in Oceans Leads to "Severe Acoustic Trauma" in Octopus, Squid

Jeremy Hance
mongabay.com
April 12, 2011

Researchers have documented for years how noise pollution impacts dolphins in whales, but a new study in Frontiers in Ecology and the Environment finds that even low intensity noise can severely injure cephalopods, which include octopus, squid, and cuttlefish. The injuries are bad enough to possibly lead to stranding and death, thereby providing a feasible explanation for a number of recent strandings, including giant squid washing ashore in Spain.

"This is the first study indicating a severe impact on invertebrates, an extended group of marine species that are not known to rely on sound for living," says Michel André, Technical University of Catalonia in Barcelona, in a press release.

Researchers subjected four species of cephalopods—European squid (Loligo vulgaris), common cuttlefish (Sepia officinalis), common octopus (Octopus vulgaris), and Southern shortfin squid (Illex coindeti)—to low intensity and low frequency sounds (between 50 and 400 Hertz) for two hours. Following the noise exposure, researchers found damage to species' statocysts, which are sensory organs that balance the cephalopods. Inside the statocysts hair cells had ruptured, nerve fibers had swelled, and some statocysts even suffered lesions. These holes continued to grow larger hours after exposure.

The European octopus, and other cephalopods, are more sensitive to even low-frequency sounds than researchers expected. Photo by: Gewöhnlicher Krake. “We expected some lesions after noise exposure but not the level of trauma that we found. What we found was typical of what you might find in mammals after violent, high intensity sound exposure,” André told The Great Beyond.

Given the low intensity of the sounds used in the experiment, researchers believe the 'louder' sounds encountered in the ocean would significantly impair squids, octopi, and cuttlefish.

"The impact of continuous, high intensity noise pollution in the oceans could be considerable. For example, we can predict that, since the statocyst is responsible for balance and spatial orientation, noise-induced damage to this structure would likely affect the cephalopod's ability to hunt, evade predators and even reproduce; in other words, this would not be compatible with life," André explains.

Underwater noise pollution is caused by offshore drilling—and other excavation activities that use seismic surveys to locate deposits—cargo transportation, industrial fishing, and even recreational boating. Studies have shown that some marine animals actually become louder to be heard when confronted with deafening sounds in their environment.

"It left us with several questions," André says, "is noise pollution capable of impacting the entire web of ocean life? What other effects is noise having on marine life, beyond damage to auditory reception systems? And just how widespread and invasive is sound pollution in the marine environment?"

Octopods Historical Origin in Question

March 5, 2011
Guardian.co.uk

A fossil octopus found in Lebanon has dramatically changed zoologists' thinking on these creatures' historic origin.

An ultraviolet picture of the octopus fossil found in Lebanon, which is more than 95m years old. Photograph: Dirk Fuchs/Free University of Berlin

Keuppia levante is one of several newly discovered fossil octopus species found in Lebanon that challenge previous assumptions about the origin and age of the Octopoda. Along with Keuppia hyperbolaris and Styletoctopus annae, this species is now the earliest unequivocal fossil for the group.

Truly remarkable anatomical details were observable due to the fine-grained Cenomanian limestones in which these species were entombed 180-95 million years ago. Octopods were previously thought to have arisen in mid-Cretaceous times. Thanks to characters observed in these newly discovered species, scientists now think octopods appeared significantly earlier, possibly even in Jurassic times.

Quentin Wheeler is director of the International Institute for Species Exploration, Arizona State University

Ancient Octopus Mystery Resolved

By Rosalind Pidcock
Science reporter, BBC News

May 19, 2010


Trapped air in the shells of rare octopuses is the key to their survival in the deep sea, say scientists.

Females of the argonaut family (Argonautidae) release trapped air from their shells to control very precisely their movement through the water.

This ability has puzzled naturalists for over 2,000 years, dating back to observations made by Aristotle in 300 BC.

Research published in the Royal Society journal, Proceedings B, finally explains why it may have evolved.

The Australian researchers describe how the mechanism enables the creatures to conserve energy, avoid predators and protect eggs during the brooding stage.

The study, led by Dr Julian Finn of Museum Victoria in Melbourne, is the first to observe directly how this unique species of octopus captures air at the sea surface and uses it to its advantage.

"It wasn't until I actually got an argonaut in the water that I really saw the true marvel of these animals," said Dr Finn.

Unlike any other species of octopus, the female argonaut, which can be up to 50cm (20 inches) in length, makes itself a paper-thin shell. It secretes this shell, made of calcium carbonate, from two web structures on the sides of its body.

The males are much smaller, typically only a centimetre in length, and do not produce shells.

Mythical Creatures
Air pockets have been observed before within the shells of both wild and captive argonauts, also known as "paper nautiluses", but their origin and purpose has until now been a mystery.

"This mythical story began around the time of Aristotle that the argonaut female actually lived in the shell and raised those webs as sails as she sailed across the ocean," explained Dr Finn.

The new findings show that the female argonaut takes in air at the sea surface through a funnel as it rotates its shell anti-clockwise. It then seals off an air pocket in the top, or apex, of the shell using a second webbed pair of tentacles.

As it dives to depths of up to 750m (almost half a mile) below the surface, it adjusts the amount of air in its shell to match its own density with that of the seawater, keeping it "neutrally buoyant" and enabling it to swim effortlessly.

This contrasts with most other cephalopods - the class of animals that includes octopuses, squid and cuttlefish - which expend vast amounts of energy to maintain their position.

Underwater Control
The female argonaut can also counteract the considerable weight of its eggs, which it releases into its shell during the reproductive period, to carefully avoid bumping them on the sea floor.

By keeping a safe position in mid-water, argonauts can also steer clear of disturbance by surface waves and predators from above, such as birds.

Once believed to hinder the females, it is now thought that argonauts evolved this remarkable mechanism from ancestors that lived on the seafloor, allowing the species to expand its range into mid-depths.

"The female argonaut knows exactly what she was doing. Underwater she was completely in control," added Dr Finn.

Octopus Fooled by HDTV

In experiments evaluating how the creatures react to moving images, the animals responded far more vigorously to HDTV than standard definition TV.

It appears that standard definition moving images are not sufficiently "convincing" for the sophisticated cephalopods, say scientists from Macquarie University.

Researchers can now use HDTV as a tool to study elements of their behavior, such as personality.

Details of the discovery are published in The Journal of Experimental Biology.

Source: Macquarie University, BBC