15 October 2015

Secret of resilience revealed in Antarctic octopod

Photo by Thomas Lundälv.

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.

[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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