Similarly, a cockroach has a "a single structure with 12 to 13 chambers." Cephalopods (cuttlefish, squid, octopus) have three hearts: two for the gills and one central heart, and that is the correct answer. read more
The hagfish has four of them, one main three-chambered systematic heart and three accessory pumps. BONUS: Humans Yes, there are seriously humans with more than one heart. read more
The human heart beats about 72 times a minute, but in that same time, a hibernating groundhog's heart beats just five times and a hummingbird's heart reaches 1,260 beats per minute during flight. The human heart weighs about 0.6 pounds (0.3 kilograms), but a giraffe's weighs about 26 pounds (12 kg), since the organ needs to be powerful enough to pump blood up the animal's long neck. read more