How Many Hearts Does an Octopus Have
3 hearts — one systemic and two branchial hearts
⚡Quick Answer
Octopuses have 3 hearts: one main systemic heart that pumps blood to the body, and two branchial hearts that pump blood through the gills. They need three hearts because their copper-based blue blood is less efficient at carrying oxygen than human blood.
Step-by-Step Guide
Quick Answer
An octopus has 3 hearts: one systemic heart that pumps blood through the body, and two branchial hearts that pump blood through the gills to collect oxygen.
Why Three Hearts?
Octopus blood contains copper-based hemocyanin (not iron-based hemoglobin like humans), which is less efficient at carrying oxygen. Three hearts compensate by providing extra pumping power to circulate blood faster.
How Each Heart Works
Systemic heart: Main heart, has 3 chambers, pumps oxygenated blood to organs and muscles | Branchial hearts (×2): One for each gill, pump deoxygenated blood through the gills to pick up oxygen before returning to the systemic heart
More Amazing Octopus Facts
9 brains: 1 central brain + 8 mini-brains (one in each arm) | Blue blood: Due to copper-based hemocyanin | 3 hearts: Systemic + 2 branchial | 0 bones: Entirely soft-bodied | 2,000+ suckers: Each with taste receptors
Frequently Asked Questions
What happens if an octopus loses a heart?
Losing a heart would likely be fatal or severely debilitating. The three-heart system is essential for proper oxygen circulation. However, octopuses can regenerate lost arms — just not hearts.
Do all cephalopods have three hearts?
Yes! Squids, cuttlefish, and nautiluses also have three hearts and blue, copper-based blood. This is a defining feature of cephalopods that helps them thrive in oxygen-poor deep ocean environments.
Why does the main heart stop when swimming?
The jet-propulsion swimming motion compresses the systemic heart, preventing it from beating effectively. This exhausts octopuses quickly, which is why they prefer crawling along the ocean floor using their arms.
What animal has the most hearts?
Hagfish have 4 hearts, earthworms have 5 pairs of 'aortic arches' (pseudo-hearts), and some argue cockroaches have 13 heart chambers. But octopuses have the most complex multi-heart system among intelligent animals.
How long do octopuses live?
Most octopuses live only 1-2 years — some giant Pacific octopuses live 3-5 years. Females often die shortly after their eggs hatch because they stop eating while guarding them. Their short lifespan is surprising given their intelligence.