Octopi, Squids, Earthworms

Squids and octopuses have three hearts with two gill hearts to force blood to the gills and a central heart to send it around the rest of the body. Earthworms are segmented in such a way that segments 7-11 have blood vessels which are more muscular than in the other segments, and are thus called the aortic arches because they pump blood through the body. Thus an earthworm is said to have 5 hearts.

Misc >Common Threads 2