Photo by Thomas Lundälv.
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At a constant temperature of -1.8°C to 2°C in the Antarctic, ectotherms adapt various
strategies to survive near-freezing temperatures. Such a condition may increase
the solubility of oxygen but increase blood viscosity, making it difficult to
deliver oxygen in tissues [1,2]. But such a dire circumstance does not thwart
the Antartic octopod’s survival in freezing waters.
However, this octopod does not only thrive in
cold temperatures, evidence suggests that a functional change in its blue-blood
pigment ‘haemocyanin' enhances oxygen supply to octopod tissues, notably at
higher temperatures. This could mean increased resiliency to warmer climate as
global warming advances in the Antarctic Peninsula
[1,2].
How does an Antartic octopod survive temperature
extremes? Researchers analyzed the haemolymph of three octopod species – the
Antarctic octopod Pareledone charcoti
and the two species residing in warmer climates, Octopus
pallidus and Eledone moschata.
They found out that P. charcoti has
one of the highest concentration of haemolymph recorded for octopods, allowing sufficient
oxygen supply. Also, relative to the two other species, oxygen transport via
haemocyanin in P. charcoti (76.7% on average) was significantly improved at 10°C compared to 0°C. Such a remarkable feat may allow
the Antarctic octopod to thrive in both warm and cold temperatures [1].
Amazing, isn’t it?
To
know more about these species and octopods in general, visit SeaLifeBase.
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[1] BioMed Central. (2015, March 10).
“Blue-blood on ice: How an Antarctic octopus survives the cold.” ScienceDaily. Retrieved March 16, 2015
from http://www.sciencedaily.com/releases/2015/03/150310205703.htm
[2] Oellermann, M., Lieb, B., Pörtner,
H.O., Semmens, J.M., Mark, F.C. (2015). Blue blood on ice: modulated blood
oxygen transport facilitates cold compensation and eurythermy in an Antarctic
octopod. Frontiers in Zoology.
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very informative and knowledgeable
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