Tenticular Gesticulation

For OCTOber Third: Three Hearts

In honer of OCTOber 3rd: Did you know that octopodes have three hearts? It's true!  They have two branchial hearts, one each for their two gills. Being molluscs, the gills are fully vascuralized and so each gill gets its own individualized heart. Then there is a third  systemic heart that pumps blood to the rest of the body.  Interestingly, octopus blood is rich in hemocyanin (a copper-rich protien) that is is dissolved in the blood plasma, as opposed to vertabrates which have hemoglobin (an iron-rich protien) that is carried in the red blood cells. Hemocyanin is much more efficient at transporting oxygen in cold conditions with low oxygen pressure.