Octopuses Have Heart (Actually, Three!)

Roses are red, violets are blue, octopuses have three hearts, do you know what they all do?

Published February 08, 2019

Octopuses are equipped with two branchial hearts and one systemic heart and each serves an important purpose. Like humans, octopuses have a closed circulatory system, meaning that closed vessels or tubes transport blood throughout their body.

Giant Pacific octopus

The two branchial hearts pump blood through the octopus’s gills, where the carbon dioxide is released and oxygen gets absorbed. This process is similar to when the right side of our hearts pass blood through our lungs!

After the blood passes through the octopus’s gills, it enters the systemic heart—the largest of the octopus’s three hearts. The systemic heart circulates the newly oxygenated blood throughout the rest of the octopus’s body and other organs, similar to the main function of the left side of a human’s heart.

The octopus’s systemic heart stops beating when this cephalopod swims, which quickly tires the octopus. This explains why octopuses are more often seen crawling along the ocean floor rather than swimming.

Despite having similar circulatory systems, the color of blood differs between octopuses and humans. Octopus blood contains a copper-rich protein—causing its distinct blue color!

Just in time for Valentine’s Day, show some love with our downloadable Aquarium-themed cards featuring some of our favorite aquatic friends!

Previous Post

Featured Stories

Manatee Manatees Visiting Maryland!

As the waters off the mid-Atlantic coast warm up, it’s not unusual to spot some seasonal visitors swimming in our local waterways—manatees!

Read the full story

Snapping turtle and red-eared sliders Floating Wetland Update: Turtles, Fish and Birds!

Several new species have been spotted on the National Aquarium’s floating wetland prototype in the Inner Harbor!

Read the full story

Related Stories

Do All Sharks Need to Keep Swimming to Breathe?

Published August 02, 2019

Where Have All the Sharks Gone?

Published July 29, 2019