They can exist as big as a piano or as well small to see without a microscope. They may beat out every bit much every bit one,000 —  or as little as half-dozen — times a minute.

They are animal hearts and they're extraordinary.

Aye, the human being heart is pretty amazing, too.  The thing has its electrical impulse, so with enough oxygen it can crush when outside of the body.

But so again, nosotros simply have one of them. The octopus has iii. And information technology simply gets more amazing from in that location.

Shell Information technology

The cheetah is one of the fastest state animals, just its resting center beat is about 120 beats per minute, similar to a jogging human. Hither'due south the deviation: While it takes some time for a human heart to accomplish its limit, usually 220 BPM, the cheetah tin go up to 250 BPM in just a few seconds.

A cheetah's heart crush can become up to 250 BPM in just a few seconds.

Actually Beat out It

The cheetah has a bit of competition, yet, with the Etruscan shrew . The smallest known mammal by mass, the Etruscan shrew weighs in at nether ii grams and has a 25 beats per second heart rate. That's a 1,500 BPM. It's besides kind of cute .

Sizing Information technology Up

The human eye is about the size of a fist — and a cow'due south heart is the size of a human head. The largest animal heart is the blue whale's , which has been weighed at nearly 400 pounds (and it is non the size of a small motorcar , opposite to popular conventionalities).

But the creature with the largest middle-to-body-mass ratio is somewhat surprising: the dog . Compare a dog'due south heart to its torso mass and it'southward a .8 percent ratio. Nigh all other animals — including elephants, mice and humans — take a .vi percentage ratio. Another creature with a ratio larger than most mammals is the dog's ancestor, the wolf.

Sizing it down

The smallest beast hearts vest to the .006-inch long fairyflies. You need a microscope to see its center, which is a tube running along its dorsum. A new species of fairyfly found in Costa rica is named Tinkerbella nana .

Room for Growth

The tropical, freshwater zebrafish is a pop aquarium addition, but information technology's the creature'south centre that deserves the virtually attention. Information technology has amazing regenerative properties, quickly closing injuries and mending itself back to almost full function.

That's why researchers study the zebrafish to uncover possible treatments for heart failure and other cardiac injuries. At the CVM, the zebrafish is helping us unlock some of the mysteries of the human being allowed organization.

The zebrafish heart has amazing regenerative backdrop, speedily endmost injuries and mending itself back to almost full function.

Triple Play

Human hearts, like those of all mammals, also as birds, take iv chambers. The heart'due south "thump-thump" sound is the 4 valves opening and closing as they pump blood. But frog hearts have iii chambers — two atria and one ventricle (you can actually see how information technology works in a glass frog ).

A Little Assistance

Really, all reptiles have three-chambered hearts with one exception. Crocodilian hearts take four chambers, but unlike mammals they have an extra flap that tin can shut to proceed blood from going to the lungs. Researchers believe the blood can be sent to the stomach to assist digestion, which is just a smidge helpful when bones are oftentimes on the menu.

Dive right in

Many animals decrease their heart rate while diving into water. An emperor penguin'south heart charge per unit dips 15 per centum from its resting rate when diving and drops even more during long dives (in between dives it jumps chop-chop, probable to replenish tissues with oxygen). A manatee heart rate cuts past one-half while on a long dive and seals decrease their heart rate from l to eighty percentage while diving. By the manner, seals consume squids , which, similar octopuses , accept 3 hearts.

A manatee cuts its heart rate by one-half while on a long dive.

Coming Up Empty

There are also numerous animals with no hearts at all, including starfish, body of water cucumbers and coral . Jellyfish tin abound quite large, simply they also don't have hearts. Or brains. Or fundamental nervous systems. Information technology'due south working for them, though. They've been around at least 500 million years.

How … cute?

Pairs of dragonflies and damselflies (damselflies are different than dragonflies and, yes, that's what they're chosen) form heart shapes when mating. The male grabs the female backside its head and the female person … uh, how nigh we just evidence you lot a photo ?

Sources: The Central Florida Zoo; National Park Service; National Wild animals Federation; Journal of Experimental Biological science; National Science Foundation

~Hashemite kingdom of jordan Bartel/NC Country Veterinary Medicine