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
Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | Johannes Gutenberg-Universität Mainz
Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
29.05.2017 | Physics and Astronomy
29.05.2017 | Physics and Astronomy
29.05.2017 | Earth Sciences