How many hearts does an octopus have?
A common octopus has three hearts.
Two of these hearts are systemic, which means they pump blood into the rest of the body, including its organs.
The other heart is the main heart.
It pumps blood through the animal’s body cavity and houses part of its respiratory system.
What Are The Three Hearts For?
The three hearts work together, sending blood in a circular motion throughout the octopus’s body.
This is called cardiopulmonary circulation.
The main heart works like a normal heart.
It pumps blood to the gills where it branches off and goes into the individual arms of the octopus.
The systemic hearts are attached to the main heart and to each other.
The blood in the octopus’s body cavities is returned to the main heart by veins that surround its gills, where oxygen from water is absorbed into the animal’s system.
A membrane called a septum covers both entrances into and exits out of this cavity and the octopus’s other organs.
The main heart pumps blood into the cavity through one opening, and out of the cavity through another.
This is where gases are exchanged between the oxygen found in water and the octopus’s blood.
The octopus exchanges about 95 percent of its lung air using this method every 24 hours.
What Are Octopus Heart Misconceptions?
There has been some discrepancy recently in the number of hearts octopuses have.
Some sources say there are six, and others only three.
The so-called sixth heart is actually a misnomer for an open connection between two main arteries that are found in all cephalopods’ blood systems.
This connection does not function as a heart and thus is not technically a heart.
However, even with three hearts, octopuses are still efficient creatures despite their lack of a pulmonary artery.
The two systemic hearts work hard to pump blood into the rest of the octopus’s body including where it needs to go for its organs to function and for oxygenation.
The main heart supplies a large amount of blood to the gills.
As octopuses grow, their hearts grow too—for example, an adult common octopus’s three hearts are roughly three times the size of a human heart.
While most octopuses do not live longer than five years, researchers believe they continue growing until just before they die.
It is possible that octopuses continue to grow throughout their entire lives.
An octopus’s blood is blue, due to the presence of three kinds of copper-rich protein in it called hemocyanin.
Hemocyanin contains negatively charged ions that can transport a great amount of oxygen, giving octopuses a greater supply than humans have.
The three hearts function together like human hearts do, with one notable exception: they can operate simultaneously or independently of each other.
