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
Showing posts with label Research. Show all posts
Showing posts with label Research. Show all posts
Thursday, June 14, 2012
Monday, June 4, 2012
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.
(o)(O)(o)(O)(o)>
Check out PressTV.com for pictures.
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.
(o)(O)(o)(O)(o)>
Check out PressTV.com for pictures.
Monday, February 20, 2012
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.
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.
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.
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.
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.
Sunday, May 29, 2011
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.
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.
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.
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.
Friday, April 15, 2011
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?"
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?"
Monday, March 7, 2011
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
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 BerlinKeuppia 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
Monday, May 24, 2010
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.
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.
Tuesday, December 22, 2009
Species: Coconut Octopus or Veined Octopus
Although originally discovered in 1964, this crafty little fella' has been making headlines all week!Amphioctopus marginatus, commonly known as Veined Octopus or Coconut Octopus, dwells in the tropical waters of the western Pacific Ocean. The Coconut Octopus is named so for a very peculiar behavior: it carries coconut shells and clam shells across the ocean floor and uses them to build fortresses. it is the only invertebrate known to use tools, and one of only two octopuses known to exhibit bipedal behavior by "walking" on two of it's legs.
The Coconut Octopus's diet consists of shrimp, crabs, and clams. The body of the Coconut Octopus is typically around 8 centimeters (3 in) in size, and, with arms, approximately 15 centimeters (6 in) long. The octopus displays a typical color pattern with dark ramified lines similar to veins, usually with a yellow siphon. The arms are usually dark in color, with contrasting white suckers. In many color displays, a lighter trapezoidal area can be seen immediately below the eye.
Although octopuses often use foreign objects as shelter, the sophisticatedbehavior of Coconut Octopus when they select materials, carry and reassemble them, is far more complex. Coconut Octopus's use of coconuts shells and clam shells hasfascinated scientists, mainly because this is the first invertebrate known to carry and maintain objects for future use. Interestingly, while the octopuses are transporting the shells, they receive no protection from them. This is highly unusual behavior.One Everything Octopus reader even contributed his take on the Coconut Octopus, which you can read HERE.
Stay tuned to Everything Octopus for more about the Coconut Octopus!
Saturday, November 28, 2009
Video: California Two-Spot Octopus Hunting at Night
The video below demonstrates the uniquely friendly temperament of the California Two-Spot Octopus as well as showcases it's wonderful hunting skills and much more. Watch and listen as Dr. James Wood, Director of Education, at Aquarium of the Pacific follows the California Two-Spot Octopus thorugh the tide-pools of Catalina Island.
Tuesday, June 16, 2009
Octopus Circulatory System
Here's a great article I found about the octopus's unique circulatory system on A Moment of Science.
When it comes to weird sea-creatures, octopuses are hard to beat. There's the well-known ink-squirting defense system, the bird-like beak, the eight tentacles with their double rows of suckers. What's less well known is that octopuses have more than one heart. They have three, to be exact, each one crucial to maintaining the robust blood pressure that allows octopuses to be active hunters and powerful swimmers.
Human hearts have two main jobs. One is to pump blood to the lungs, where it dumps carbon dioxide and picks up oxygen. The second is to distribute freshly oxygenated blood to the rest of the body. Making sure enough blood gets to the lungs is so important, in fact, that two of the human heart's four chambers are reserved solely for that task.
Octopus hearts solve the circulation problem a bit differently. They have one main heart, called the systemic heart, and two smaller hearts located near their gills. The two smaller hearts perform the same task as the right side of the human heart. They pump blood to the gills where it dumps waste and loads up on oxygen, then pump the oxygen-rich blood back to the main heart. The main heart then pumps the refreshed blood through the octopus's body.
Besides having three hearts, the octopus circulatory system differs from the human system in one other way. Humans blood contains the protein hemoglobin, which helps it absorb oxygen and causes its red color. The blood coursing through the three hearts of the octopus is blue, thanks to a different protein called hemocyanin.
Octopuses are rather shy, so despite their blue blood they are not exactly kings of the sea. But there's no denying that they've got a lot of heart.
When it comes to weird sea-creatures, octopuses are hard to beat. There's the well-known ink-squirting defense system, the bird-like beak, the eight tentacles with their double rows of suckers. What's less well known is that octopuses have more than one heart. They have three, to be exact, each one crucial to maintaining the robust blood pressure that allows octopuses to be active hunters and powerful swimmers.
Human hearts have two main jobs. One is to pump blood to the lungs, where it dumps carbon dioxide and picks up oxygen. The second is to distribute freshly oxygenated blood to the rest of the body. Making sure enough blood gets to the lungs is so important, in fact, that two of the human heart's four chambers are reserved solely for that task.
Octopus hearts solve the circulation problem a bit differently. They have one main heart, called the systemic heart, and two smaller hearts located near their gills. The two smaller hearts perform the same task as the right side of the human heart. They pump blood to the gills where it dumps waste and loads up on oxygen, then pump the oxygen-rich blood back to the main heart. The main heart then pumps the refreshed blood through the octopus's body.
Besides having three hearts, the octopus circulatory system differs from the human system in one other way. Humans blood contains the protein hemoglobin, which helps it absorb oxygen and causes its red color. The blood coursing through the three hearts of the octopus is blue, thanks to a different protein called hemocyanin.
Octopuses are rather shy, so despite their blue blood they are not exactly kings of the sea. But there's no denying that they've got a lot of heart.
Sunday, June 7, 2009
Duke to Share a $7.5 Million Study on Octopuses
From Triangle Business Journal
May 20, 2009
Researchers at Duke University will share part of a $7.5 million grant to study how octopuses and squid use mental powers to camouflage themselves.
The five-year Multidisciplinary University Research Initiative (MURI) study is funded by the Office of Naval Research and includes researchers from Duke, the University of California at Santa Barbara and UC San Diego’s Scripps Institute of Oceanography.
Sonke Johnsen, a Duke associate professor of biology and the project’s principal investigator, says they are looking to study how cephalopods, the hundreds of species classified as octopuses or squids, see the world and respond.
Cephalopods have the ability to adjust their skin colors and patterns to hide from predators or prey. Some are even able to emit their own light to eliminate shadows that would expose their silhouettes.
To conduct their study, the researchers will construct a “Star Trek”-like underwater holodeck that will allow researchers to manipulate lighting to mimic ocean conditions and see how enclosed creatures respond.
"We will be able to change the colors, resolution, speed and everything else so that we can step inside their visual world under laboratory conditions," Johnsen said. "We will be able to show them natural scenes, but then also scenes that have been altered in different ways. The holodeck will be like a virtual reality machine for the ocean. In the world of marine biology we know of no other like it."
A second group of researchers led by the University of Texas at Austin will work toward similar goals. They also received $7.5 million from the Navy.
The Duke-led researchers will conduct expeditions on islands off California and the Pacific Island of Palau while the Texas group will work in the Florida Keys and the Gulf of Mexico.
Monday, April 20, 2009
Octopus with 96 Tentacles!
The better to hold you with, my dear...
This is old news, but fascinating nonetheless. The octopus pictured below has 88 additional tentacles, a rarity, even for a creature as strange as the octopus.
This strange specimen is on permanent display at the Shima Marineland Aquarium in Japan. The octopus actually has 8 arms attached to its body, and the additional 84 tentacles are all extensions of those 8.
The 96-tentacled Common Octopus (Octopus vulgaris) was captured in 1998 in nearby Matoya Bay. It weighed 3.3 kilograms (about 7 lbs) and measured 90 centimeters (3 ft) long. Before dying 5 months after being placed in captivity, the creature laid eggs, making it the first known extra-tentacled octopus to do so in captivity. All the baby octopuses hatched with the normal number of tentacles, but unfortunately they only survived a month.
Currently there is no theory that fully explains the surplus tentacles, although speculation maintains the oddity to be the result of abnormal regeneration that occurred after the octopus suffered some sort of injury.
In the above photo, the 96-tentacled female octopus can be seen laying eggs.
This is old news, but fascinating nonetheless. The octopus pictured below has 88 additional tentacles, a rarity, even for a creature as strange as the octopus.
This strange specimen is on permanent display at the Shima Marineland Aquarium in Japan. The octopus actually has 8 arms attached to its body, and the additional 84 tentacles are all extensions of those 8.
The 96-tentacled Common Octopus (Octopus vulgaris) was captured in 1998 in nearby Matoya Bay. It weighed 3.3 kilograms (about 7 lbs) and measured 90 centimeters (3 ft) long. Before dying 5 months after being placed in captivity, the creature laid eggs, making it the first known extra-tentacled octopus to do so in captivity. All the baby octopuses hatched with the normal number of tentacles, but unfortunately they only survived a month.
Currently there is no theory that fully explains the surplus tentacles, although speculation maintains the oddity to be the result of abnormal regeneration that occurred after the octopus suffered some sort of injury.
Tuesday, April 14, 2009
Primitive Octopus Fossil: Pohlsepia Mazonensis
From: Tonmo.com
Written by: Phil Eyden, November 2004
Pohlsepia mazonensis was named after the person who discovered it, James Pohl, and the location, Mazon Creek. It is the earliest octopod that has been described to date and is approximately 296 million years old. Up until the recent discovery and publication of Pohlsepia in 2000 it was thought that the octopus lineage stemmed from the vampyromorphs sometime in the mid Jurassic, so it is obvious how important this discovery was of a soft-bodied octopod from the Upper Carboniferous (Pennsylvannian) as it pushed the origin of the octopus group back at least 140 million years further. It is important to remember that Pohlsepia clearly had its own ancestors and even at this early date had clearly defined cirrate-octopus features. The true origin of the octopods must have happened a few million years before even this remarkable fossil.
The fossil hails from the Upper Carboniferous deposits at Mazon Creek in Illinois, a source of extensive coal deposits. Many other cephalopods have been found in these deposits including nautiloids and the shelled torpedo-shaped ten-armed coleoid known as Jeletzkya. Specifically Pohlsepia comes from the Francis Creek Shale Member, this site of exceptional preservation consisted of rapid deposition of silt and sediments believed to have been at the mouth of a river delta where it met the sea. It is believed that storm surges following heavy rains swept masses of sediment down the river and out to sea burying coastal and marine animals and vegetation extremely rapidly. Concretions of ironstone then formed around the dead animals very quickly. Pohlsepia originates from the 'Essex' marine deposits and is preserved as a carbon film resembling a compressed stain inside one such nodule; this is typical for most fossils from Mazon Creek.
Just one example of Pohlsepia is known; as it is in a primitive condition the octopod actually has ten arms, two of these were modified but the other eight were approximately of the same length. The animal is small and is estimated to have had a Mantle Length of just 25mm long by 35mm wide. The animal lacks an internal shell much as with modern cirrate octopuses. The animal is sack shaped, has no clearly defined head and has very short arms. It also had two fins on its mantle, which are longer than they are wide, much like modern cirrate octopuses. The fossil has been preserved in a ventral aspect, eyes, a funnel, mandibles and a radula are identifiable and there is an indistinct feature that may represent an ink sac (extant cirrate octopods do not have these). No arm hooks or suckers are present. Peter Doyle and Joanne Kluessendorf published the fossil in 2000 and they have concluded that Pohlsepia should be assigned to the order Cirroctopoda.
Pohlsepia is housed at the Field Museum of Natural History, Chicago, Illinois.
Written by: Phil Eyden, November 2004
Pohlsepia mazonensis was named after the person who discovered it, James Pohl, and the location, Mazon Creek. It is the earliest octopod that has been described to date and is approximately 296 million years old. Up until the recent discovery and publication of Pohlsepia in 2000 it was thought that the octopus lineage stemmed from the vampyromorphs sometime in the mid Jurassic, so it is obvious how important this discovery was of a soft-bodied octopod from the Upper Carboniferous (Pennsylvannian) as it pushed the origin of the octopus group back at least 140 million years further. It is important to remember that Pohlsepia clearly had its own ancestors and even at this early date had clearly defined cirrate-octopus features. The true origin of the octopods must have happened a few million years before even this remarkable fossil.
The fossil hails from the Upper Carboniferous deposits at Mazon Creek in Illinois, a source of extensive coal deposits. Many other cephalopods have been found in these deposits including nautiloids and the shelled torpedo-shaped ten-armed coleoid known as Jeletzkya. Specifically Pohlsepia comes from the Francis Creek Shale Member, this site of exceptional preservation consisted of rapid deposition of silt and sediments believed to have been at the mouth of a river delta where it met the sea. It is believed that storm surges following heavy rains swept masses of sediment down the river and out to sea burying coastal and marine animals and vegetation extremely rapidly. Concretions of ironstone then formed around the dead animals very quickly. Pohlsepia originates from the 'Essex' marine deposits and is preserved as a carbon film resembling a compressed stain inside one such nodule; this is typical for most fossils from Mazon Creek.
Just one example of Pohlsepia is known; as it is in a primitive condition the octopod actually has ten arms, two of these were modified but the other eight were approximately of the same length. The animal is small and is estimated to have had a Mantle Length of just 25mm long by 35mm wide. The animal lacks an internal shell much as with modern cirrate octopuses. The animal is sack shaped, has no clearly defined head and has very short arms. It also had two fins on its mantle, which are longer than they are wide, much like modern cirrate octopuses. The fossil has been preserved in a ventral aspect, eyes, a funnel, mandibles and a radula are identifiable and there is an indistinct feature that may represent an ink sac (extant cirrate octopods do not have these). No arm hooks or suckers are present. Peter Doyle and Joanne Kluessendorf published the fossil in 2000 and they have concluded that Pohlsepia should be assigned to the order Cirroctopoda.
Pohlsepia is housed at the Field Museum of Natural History, Chicago, Illinois.
Sunday, April 5, 2009
Rare Octopus Fossil from Lebanon
The following information and pictures are from FossilMuseum.net.
Paleoctopus newboldi
Phylum Mollusca, Class Cephalopoda, Order Octopoda
Geologic Time: Middle Cretaceous, Cenomanian Stage (~95 million years ago)
Size: 85 mm long and 27 mm across tentacles
Fossil Site: Lebanese Lagerstatt, Haqel, Lebanon
Description: Here is a most unusual fossil from the Cretaceous of Lebanon; a very detailed octopus. Given the fact that there are no hard parts to preserve to speak of, the detail here is amazing, and testiment to the exceptional preservation often found in the Lebanese Lagerstatt. The last photo has been enhanced to bring out some features which are somewhat faint. The darkest area is actually preserved ink which the octopus would have used as a smokescreen to protect it from predators.
Paleoctopus newboldi
Phylum Mollusca, Class Cephalopoda, Order Octopoda
Geologic Time: Middle Cretaceous, Cenomanian Stage (~95 million years ago)
Size: 85 mm long and 27 mm across tentacles
Fossil Site: Lebanese Lagerstatt, Haqel, Lebanon
Description: Here is a most unusual fossil from the Cretaceous of Lebanon; a very detailed octopus. Given the fact that there are no hard parts to preserve to speak of, the detail here is amazing, and testiment to the exceptional preservation often found in the Lebanese Lagerstatt. The last photo has been enhanced to bring out some features which are somewhat faint. The darkest area is actually preserved ink which the octopus would have used as a smokescreen to protect it from predators.
Thursday, April 2, 2009
Octopus Fossils - They're More Rare Than You Think!
From: Tonmo.com, November 2004
Written by: Phil Eyden
Fossils of octopuses are by far the most enigmatic and mysterious of all the ancient groups of cephalopods. Due to their delicate structure fossils of these animals are exceptionally rare, as the soft-bodied nature of the animal does not lend itself to fossilisation. They are so rare that there is just one known from Illinois (296million years old), one from France (164m) and just a handful from Lebanon (89-71m). Very little is known about their history, how they evolved and developed, or their lifestyle. Following is a brief look at some of the theories surrounding them, the three octopuses themselves and the sites they were found in. It should be remembered that these three forms almost certainly do not represent a single line of descent.
Written by: Phil Eyden
Fossils of octopuses are by far the most enigmatic and mysterious of all the ancient groups of cephalopods. Due to their delicate structure fossils of these animals are exceptionally rare, as the soft-bodied nature of the animal does not lend itself to fossilisation. They are so rare that there is just one known from Illinois (296million years old), one from France (164m) and just a handful from Lebanon (89-71m). Very little is known about their history, how they evolved and developed, or their lifestyle. Following is a brief look at some of the theories surrounding them, the three octopuses themselves and the sites they were found in. It should be remembered that these three forms almost certainly do not represent a single line of descent.
Saturday, March 28, 2009
Robotic Octopus to Solve Mysteries of the Sea
From Thaindan.com, March 22, 2009
London, Mar 22 (ANI): Scientists are developing a robotic octopus that will be able to search the seabed with the same extraordinary dexterity as the real eight-legged cephalopod.
With no solid skeleton, the robot would be the world’’s first entirely soft robot, say researchers.
The trouble with today’’s remote-controlled subs, says researcher Cecilia Laschi of the Italian Institute of Technology in Genoa, is that their large hulls and clunky robot arms cannot reach into the nooks and crannies of coral reefs or the rock formations on ocean floors.
This implies they are unable to photograph objects in these places or pick up samples for analysis. And that’’s a major minus point for oceanographers hunting for signs of climate change in the oceans and on coral reefs.
Since an octopus’’s tentacles can bend in all directions and quickly thin and elongate to almost twice their length, they can reach, grasp and manipulate objects in tiny spaces with dexterity.
“So we are replicating the muscular structure of an octopus by making a robot with no rigid structure - and that is completely new to robotics,” New Scientist quoted Laschi, as saying.
Laschi and colleagues in the UK, Switzerland, Turkey, Greece and Israel are testing artificial muscle technologies that will more accurately mimic tentacles.
The team plans to mimic the longitudinal muscles with soft silicone rubber interspersed with a type of electroactive polymer (EAP) called a dielectric elastomer. Apply an electric field to this material and it squeezes the silicone, making it shorter.
The study has been published in Biomimetics and Bioinspiration. (ANI)
London, Mar 22 (ANI): Scientists are developing a robotic octopus that will be able to search the seabed with the same extraordinary dexterity as the real eight-legged cephalopod.
With no solid skeleton, the robot would be the world’’s first entirely soft robot, say researchers.
The trouble with today’’s remote-controlled subs, says researcher Cecilia Laschi of the Italian Institute of Technology in Genoa, is that their large hulls and clunky robot arms cannot reach into the nooks and crannies of coral reefs or the rock formations on ocean floors.
This implies they are unable to photograph objects in these places or pick up samples for analysis. And that’’s a major minus point for oceanographers hunting for signs of climate change in the oceans and on coral reefs.
Since an octopus’’s tentacles can bend in all directions and quickly thin and elongate to almost twice their length, they can reach, grasp and manipulate objects in tiny spaces with dexterity.
“So we are replicating the muscular structure of an octopus by making a robot with no rigid structure - and that is completely new to robotics,” New Scientist quoted Laschi, as saying.
Laschi and colleagues in the UK, Switzerland, Turkey, Greece and Israel are testing artificial muscle technologies that will more accurately mimic tentacles.
The team plans to mimic the longitudinal muscles with soft silicone rubber interspersed with a type of electroactive polymer (EAP) called a dielectric elastomer. Apply an electric field to this material and it squeezes the silicone, making it shorter.
The study has been published in Biomimetics and Bioinspiration. (ANI)
Thursday, March 19, 2009
Cretaceous Octopus With Ink And Suckers -- The World's Least Likely Fossils?
From: Science Daily, March 18, 2009
New finds of 95 million year old fossils reveal much earlier origins of modern octopuses. These are among the rarest and unlikeliest of fossils. The chances of an octopus corpse surviving long enough to be fossilized are so small that prior to this discovery only a single fossil species was known, and from fewer specimens than octopuses have legs.
Even if you have never encountered an octopus in the flesh, the eight arms, suckers, and sack-like body are almost as familiar a body-plan as the four legs, tail and head of cats and dogs. Unlike our vertebrate cousins, however, octopuses don't have a well-developed skeleton. And while this famously allows them to squeeze into spaces that a more robust animal could not, it does create problems for scientists interested in evolutionary history. When did octopuses acquire their characteristic body-plan, for example? Nobody really knows, because fossil octopuses are rarer than, well, pretty much any very rare thing you care to mention.
The body of an octopus is composed almost entirely of muscle and skin, and when an octopus dies, it quickly decays and liquefies into a slimy blob. After just a few days there will be nothing left at all. And that assumes that the fresh carcass is not consumed almost immediately by hungry scavengers. The result is that preservation of an octopus as a fossil is about as unlikely as finding a fossil sneeze, and none of the 200-300 species of octopus known today has ever been found in fossilized form. Until now, that is.
Palaeontologists have just identified three new species of fossil octopus discovered in Cretaceous rocks in Lebanon. The five specimens, described in the latest issue of the journal Palaeontology, are 95 million years old but, astonishingly, preserve the octopuses' eight arms with traces of muscles and those characteristic rows of suckers. Even traces of the ink and internal gills are present in some specimens. '
"These are sensational fossils, extraordinarily well preserved," says Dirk Fuchs of the Freie University Berlin, lead author of the report. But what surprised the scientists most was how similar the specimens are to modern octopus: "these things are 95 million years old, yet one of the fossils is almost indistinguishable from living species." This provides important evolutionary information. "The more primitive relatives of octopuses had fleshy fins along their bodies. The new fossils are so well preserved that they show, like living octopus, that they didn't have these structures." This pushes back the origins of modern octopus by tens of millions of years, and while this is scientifically significant, perhaps the most remarkable thing about these fossils is that they exist at all.
New finds of 95 million year old fossils reveal much earlier origins of modern octopuses. These are among the rarest and unlikeliest of fossils. The chances of an octopus corpse surviving long enough to be fossilized are so small that prior to this discovery only a single fossil species was known, and from fewer specimens than octopuses have legs.
Even if you have never encountered an octopus in the flesh, the eight arms, suckers, and sack-like body are almost as familiar a body-plan as the four legs, tail and head of cats and dogs. Unlike our vertebrate cousins, however, octopuses don't have a well-developed skeleton. And while this famously allows them to squeeze into spaces that a more robust animal could not, it does create problems for scientists interested in evolutionary history. When did octopuses acquire their characteristic body-plan, for example? Nobody really knows, because fossil octopuses are rarer than, well, pretty much any very rare thing you care to mention.
The body of an octopus is composed almost entirely of muscle and skin, and when an octopus dies, it quickly decays and liquefies into a slimy blob. After just a few days there will be nothing left at all. And that assumes that the fresh carcass is not consumed almost immediately by hungry scavengers. The result is that preservation of an octopus as a fossil is about as unlikely as finding a fossil sneeze, and none of the 200-300 species of octopus known today has ever been found in fossilized form. Until now, that is.Palaeontologists have just identified three new species of fossil octopus discovered in Cretaceous rocks in Lebanon. The five specimens, described in the latest issue of the journal Palaeontology, are 95 million years old but, astonishingly, preserve the octopuses' eight arms with traces of muscles and those characteristic rows of suckers. Even traces of the ink and internal gills are present in some specimens. '
"These are sensational fossils, extraordinarily well preserved," says Dirk Fuchs of the Freie University Berlin, lead author of the report. But what surprised the scientists most was how similar the specimens are to modern octopus: "these things are 95 million years old, yet one of the fossils is almost indistinguishable from living species." This provides important evolutionary information. "The more primitive relatives of octopuses had fleshy fins along their bodies. The new fossils are so well preserved that they show, like living octopus, that they didn't have these structures." This pushes back the origins of modern octopus by tens of millions of years, and while this is scientifically significant, perhaps the most remarkable thing about these fossils is that they exist at all.
Sunday, March 1, 2009
Life Cycle of an Octopus
The first thing that happens to the octopus in the life cycle of an octopus is that it hatches from an egg. The young larval octopuses spend a period of time drifting in clouds of plankton, where they feed on copepods, larval crabs and larval starfish until they are ready to sink down to the bottom of the ocean, where the cycle repeats itself. In some deeper dwelling species, such as the Dumbo Octopus, the young do not go through this period. This is a dangerous time for the larval octopuses; as they become part of the plankton cloud they are vulnerable to many plankton eaters.
A juvenile octopus grows at a rapid rate, perhaps because of its short life span. Extremely effective at turning the food it eats into body mass, a young octopus increases its weight by 5 percent each day. By the end of its life, an octopus will weigh one-third as much as all the food it has eaten. Should a larval octopus be fortunate enough to survive this difficult period, it enters into the next stage of its life: it grows into an adult octopus.
Around the age of 1 or 2 years old, the full-grown octopus is ready to mate. When octopuses reproduce, males use a specialized arm called a hectocotylus to insert spermatophores (packets of sperm) into the female's mantle cavity. The hectocotylus in benthic octopuses is usually the third right arm. Males die within a few months of mating. In some species, the female octopus can keep the sperm alive inside her for weeks until her eggs are mature.
Blue-ringed octopus male and female mating; see the male inserting his reproductive tentacle into the female's funnel
After the eggs have been fertilized, the female lays about 200,000 eggs (this figure dramatically varies between families, genera, species and also individuals). The female hangs these eggs in strings from the ceiling of her lair, or individually attaches them to the substrate depending on the species. The female cares for the eggs, guarding them against predators, and gently blowing currents of water over them so that they get enough oxygen.
Photo of Giant Pacific Octopus eggs by Brandon Cole.
The female does not eat during the two to ten month period spent taking care of the unhatched eggs (Incubation period varies according to species and water temperature). At around the time the eggs hatch, the mother dies.
Then, we are back to the beginning of the life cycle of an octopus.
Eggs and one newborn Pacific Giant Octopus.
A juvenile octopus grows at a rapid rate, perhaps because of its short life span. Extremely effective at turning the food it eats into body mass, a young octopus increases its weight by 5 percent each day. By the end of its life, an octopus will weigh one-third as much as all the food it has eaten. Should a larval octopus be fortunate enough to survive this difficult period, it enters into the next stage of its life: it grows into an adult octopus.
Around the age of 1 or 2 years old, the full-grown octopus is ready to mate. When octopuses reproduce, males use a specialized arm called a hectocotylus to insert spermatophores (packets of sperm) into the female's mantle cavity. The hectocotylus in benthic octopuses is usually the third right arm. Males die within a few months of mating. In some species, the female octopus can keep the sperm alive inside her for weeks until her eggs are mature.
After the eggs have been fertilized, the female lays about 200,000 eggs (this figure dramatically varies between families, genera, species and also individuals). The female hangs these eggs in strings from the ceiling of her lair, or individually attaches them to the substrate depending on the species. The female cares for the eggs, guarding them against predators, and gently blowing currents of water over them so that they get enough oxygen.
The female does not eat during the two to ten month period spent taking care of the unhatched eggs (Incubation period varies according to species and water temperature). At around the time the eggs hatch, the mother dies.
Then, we are back to the beginning of the life cycle of an octopus.
Tuesday, November 11, 2008
Octopuses Have "Living Ancestor", Part II
From: news.bbc.co.uk
Written by: Mark Kinver, Science and environment reporter
'Unprecedented project'
The deep-sea octopus study, along with dozens of other projects, form part of the census's fourth progress report, which will be presented at the World Conference on Marine Biology, which begins in Valencia, Spain, on Tuesday.
The overarching objectives of the global collaboration between CoML's scientists include:
- Advancing technology for discoveries
- Organising knowledge about marine life, and making it accessible
- Measuring effects of human activities on ocean life
- Providing the foundation for scientifically based policies
Dr O'Dor said that the main focus of the CoML for the remaining two years was to "synthesise" the data.
"Many of our projects have already completed their fieldwork and we have a lot of information," he observed.
 | CoML RESEARCH RESULTS  An array of receivers in the Pacific Ocean reveal fish migration routes  |
"What we are now trying to do is to bring all that information together in a form that allows the public to understand how much we have learned about the ocean and what lives in it."
As far as improving our understanding of life beneath the waves, Dr O'Dor said: "It has been successful beyond what I imagined when I first became involved.
"It will provide a baseline. We are not going to know everything about what is happening within the oceans, but we have samplings of most marine habitats.
"We are moving into this period of global warming, which is resulting in the acidification of the oceans, melting of the polar ice cap.
"We can use the first census as a benchmark to see what happens in the oceans over the next decade or more."
Meeting formally for the first time at the five-day gathering in Valencia will be the CoML's Science Council, which will take an overview of the 10-year Census.
"Over the past few years, there has been huge public interest in biodiversity because there is a legitimate concern about the changes being caused by humans," commented Patricia Miloslavich, the Census's co-senior scientist.
"The Science Council will (consider) what people have said about areas that have not been explored or taxonomic groups that have been overlooked in the past," she told BBC News.
"We have had this first census that has given outstanding and amazing results for many ecosystems and regions.
"But now that we have been able to identify where there are some gaps, we would like to explore these areas."
Dr Miloslavich added that the Science Council will also develop the objectives of the second census, which will run from 2010 until 2020.
Monday, November 10, 2008
Octopuses Share "Living Ancestor", Part I
From: news.bbc.co.uk
Written by: Mark Kinver, Science and environment reporter
Many of the world's deep-sea octopuses evolved from a common ancestor, whose closest living relative still exists in the Southern Ocean, a study has shown.
Researchers suggest that the creatures evolved after being driven to other ocean basins 30 million years ago by nutrient-rich and salty currents.
The findings form part of a decade-long global research programme to learn more about life in the world's oceans.
The first Census of Marine Life (CoML) is set to be completed in late 2010.
The project, which began back in 2000, involves more than 2,000 scientists from 82 nations.
The research into the evolution of deep-sea octopuses was part of a programme called the Census of Antarctic Marine Life (CAML), explained Ron O'Dor, CoML's co-senior scientist.
"Many of these octopuses were collected from the deep sea by a number of the CoML's different projects," he told BBC News.
"All of that material was brought together and made available to Dr Jan Strugnell, a biologist at Queen's University Belfast, and she used this material to carry out DNA studies.
"She was looking at the relationship between these different deep-sea octopuses and how they originated.
(Right) Octopus specimens collected by Census of Marine Life researchers.
"She has been able to trace the timeline for their distribution back 30 million years to a common ancestor."
The species could all be traced back to a shallow-water octopus that lived in the Southern Ocean. Today, the creature's closest living relative (Megaleledone setebos) can still be found in the icy waters around Antarctica.
Dr O'Dor added that Dr Strugnell's work also enabled her to identify how changes in the region's ocean played a pivotal role in the development of the new species, especially the emergence of a "thermohaline expressway".
"When you get an increase in sea ice, fresh water forms ice crystals and leaves behind high-salinity, high-oxygen water, which is denser than the surrounding sea water, so it sinks," he explained.
|  We can use the first census as a benchmark to see what happens in the oceans over the next decade or more  Dr Ron O'Dor, CoML's co-senior scientist |
"It gets mixed by sea currents and flows into all of the deepest parts of the ocean.
"At the time this process started, there was no oxygen at the bottom of the ocean, so it brought oxygen into these areas, and we can now see that the octopuses moved out from the Antarctic into deeper water."
Dr Strugnell's work, supported by the UK's Antarctic Funding Initiative (AFI) and the National Environment Research Council (Nerc), also showed how the creatures adapted to the new deep-sea environment.
One example was the loss of their ink sacs, because there was no need for the defence mechanism in the pitch black waters.
As well as being one of the CoML's highlights, the research is also being published in the journal Cladistics on Tuesday.
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