Octopus Respiration

The Giant Pacific Octopus

Respiration

Octopus don't have lungs. They use gills to respire. The gills are located inside the mantle cavity, behind the mouth. As the octopus moves, water gets passed into its mouth to the gills and back out. The gills are made up of many feathery filaments. This filaments allow for a larger surface area, which the oxygenated water is passed over. As the water is pushed over the surface of the gills, oxygen is picked up by the blood. Because there is more oxygen in the water than there is in the blood, it diffuses from the water into the blood stream. The blood travels in an opposite direction in the gills than the water is traveling, which allows for a maximum oxygen exchange per breath. An octopus has three hearts. Two of the three pump the blood through the gills. The oxygenated blood that leaves the gills is pumped throughout the rest of the body by the third heart. That's how the cells in an octopus get the needed oxygen.