An Antarctic octopus that lives in ice-cold water uses an unique strategy to transport oxygen in its blood, according to research published in the open access journal 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 oxygen to tissues in the cold due to lower oxygen diffusion and increased blood 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 oxygen supply in the cold.
Lead author Michael Oellermann from the 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.”
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.
Notes for Editors
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, http://dx.doi.org/10.1186/s12983-015-0097-x
Your scientific contact person is Michael Oellermann (e-mail: michael.oellermann(at)awi.de). Your contact person in the Dept. of Communications and Media Relations is Folke Mehrtens (phone +49 471 4831-2007; e-mail: Folke.Mehrtens(at)awi.de).
The Alfred Wegener Institute conducts research in the Arctic, Antarctic and in the high and mid-latitude oceans. The Institute coordinates German polar research and provides important infrastructure such as the research icebreaker Polarstern and research stations in the Arctic and Antarctic to the national and international scientific world. The Alfred Wegener Institute is one of the 18 research centres of the Helmholtz Association, the largest scientific organisation in Germany.
Ralf Röchert | idw - Informationsdienst Wissenschaft
Closing the carbon loop
08.12.2016 | University of Pittsburgh
Newly discovered bacteria-binding protein in the intestine
08.12.2016 | University of Gothenburg
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Life Sciences
08.12.2016 | Physics and Astronomy
08.12.2016 | Materials Sciences