Blue blood on ice: How an Antarctic octopus survives the cold

Blue blood on ice: How an Antarctic octopus survives the cold
Antarctic octopod Pareledone sp. Credit: Tomas Lundälv

An Antarctic octopus that lives in ice-cold water uses an unique strategy to transport oxygen in its blood, according to research published in Frontiers in Zoology. The study suggests that the octopus's specialized blood pigments could help to make it more resilient to climate change than Antarctic fish and other species of octopus.

The Antarctic Ocean hosts rich and diverse fauna despite inhospitable temperatures close to freezing. While it can be hard to deliver to tissues in the cold due to lower oxygen diffusion and increased viscosity, ice-cold waters already contain large amounts of dissolved oxygen.

In Antarctic fish, this reduces the need for active oxygen transport by blood pigments (e.g. haemoglobin), but little is known about the adaptations employed by blue-blooded octopods to sustain in the cold.

Lead author Michael Oellermann from Alfred-Wegener-Institute, Germany, said: "This is the first study providing clear evidence that the octopods' blue blood pigment, haemocyanin, undergoes functional changes to improve the supply of oxygen to tissue at sub-zero temperatures. This is important because it highlights a very different response compared to Antarctic fish to the cold conditions in the Southern Ocean. The results also imply that due to improved oxygen supply by haemocyanin at higher temperatures, this octopod may be physiologically better equipped than Antarctic fishes to cope with global warming."

Antarctic octopod Megaleledone setebos. Credit: Tomas Lundälv

Octopods have three hearts and contractile veins that pump 'haemolymph', which is highly enriched with the blue oxygen transport protein haemocyanin (analogous to haemoglobin in vertebrates).

To find out what makes the haemocyanin of an Antarctic octopus so well-adapted to cold water, the researchers collected and analyzed the haemolymph from the abundant Antarctic octopod species Pareledone charcoti, and two octopod species collected from warmer climates - the South-east Australian Octopus pallidus and the Mediterranean Eledone moschata.

The Antarctic octopus Pareledone charcoti had the highest concentration of haemocyanin in its blood - at least 40% more compared to the other species, and ranked amongst the highest levels reported for any octopod. The researchers say that these high blood pigment concentrations may be compensating for the haemocyanin's poor ability to release oxygen to tissues while in cold environments, and could help to ensure sufficient oxygen supply.

The Antarctic octopod haemocyanin was also found to shuttle oxygen between gills and tissue far better at 10°C than at 0°C. At 10°C the Antarctic octopod's haemocyanin had the potential to release far more oxygen (on average 76.7%) than the warm-water octopods Octopus pallidus (33.0%) and Eledone moschata (29.8%). This ability may help the Antarctic octopod tolerate warmer temperatures in addition to the cold, and may link to the life style of Pareledone charcoti, which is also reported to reside in warmer shallow waters and rock pools.

Considering the strong warming trend at the Antarctic Peninsula, Pareledone charcoti may eventually benefit from its capacity to adjust blood oxygen supply to more variable temperatures than other species, including Antarctic fish.

The new findings show how the blood pigment haemocyanin in octopods is able to support oxygen supply in both cold and warm environments, and could help explain why octopods remain so populous across a wide spectrum of ecological niches.

While haemocyanin has proved to be crucial to Antarctic octopods, more comprehensive insight is needed to predict their fate in a warming ocean.


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More information: Michael Oellermann, Bernhard Lieb, Hans O Pörtner, Jayson M Semmens and Felix C Mark , Blue blood on ice: Modulated blood oxygen transport facilitates cold compensation and eurythermy in an Antarctic octopod. Frontiers in Zoology 2015. DOI: 10.1186/s12983-015-0097-x
Journal information: Frontiers in Zoology

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Citation: Blue blood on ice: How an Antarctic octopus survives the cold (2015, March 10) retrieved 15 October 2019 from https://phys.org/news/2015-03-blue-blood-ice-antarctic-octopus.html
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Mar 10, 2015
And to think that some scientists want to attribute this to time and chance!
The more we find out, the more we realize that we are truly created wonderfully.


And to think that some plebs off the street want to attribute this to a magic faerie in the sky. The more we find out, the more we realize we have no effing clue where we came from, and only scientific theory can fill that gap.

Mar 11, 2015
And to think that some scientists want to attribute this to time and chance!
@verkle
you should at least try to get a high school education in science before commenting here because you are making yourself and your religion look bad
Start here: http://www.talkor...ion.html

because anyone with the ability to COUNT can debunk your religious claims about the age of the Earth by simply counting the rings in the Bristlecone Pine tree

https://en.wikipe...one_pine

that single tree debunks your entire sky faerie hallucination and continuous religious rants

but you will not read the SCIENCE because of your religion and the fear of finding out you are being lied to

http://www.ploson...tion=PDF


Mar 11, 2015
verkle claimed
And to think that some scientists want to attribute this to time and chance
Work out the permutations & the FACT all DNA base pairs can 'self-assemble' from very common constituents in the early Earth's atmosphere - ie High NH3 leading to amines ie having an NH2 radical etc THEN, u realise, despite our awe, process of generating complexity out of simplicity according to 'survival of the fittest' becomes self-evident & appreciated by intelligent unbiased unhypnotised independent researchers :-)

Eg. Formamide from energy & early atmosphere, Guanine (a DNA base) subsequently and all others by permutations & variations...

Heard of genetic algorithms which routinely create immense complexity from simple rules ?

verkle claimed
The more we find out, the more we realize that we are truly created wonderfully
Sure but, by what & how does it communicate - anything better than via humans ?

Notice all through nature "eat & be eaten" ie All suffer !

Mar 11, 2015
Captain Stumpy offered
@verkle
you should at least try to get a high school education in science before commenting here because you are making yourself and your religion look bad
Start here: http://www.talkor...ion.html
One wonders at verkle's cognition & understanding of authority re his religious base.

ie. Catholic church re their vatican archives has several texts relating to Moswes & early bible writings & many translations, none of which considered "perfect". It should be noted there is no other religion that has Provenance that old & even before Constantine, so therefore it has to be recognised the catholic church as centered in Rome has much more reliable 'authority' re any interpretations of Moses than all others !

verkle, should know & Note

Catholic church accepts old testament is allegory & not definitive re history AND the catholic church accepts evolution as factual, they studied it.

So verkle, which odd cult r u from ?

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