[arunc]

> Looking at the big picture, the researchers think the whale’s heart is performing near its limits. This may help explain why no animal has ever been larger than a blue whale – because the energy needs of a larger body would outpace what the heart can sustain.

Fascinating to learn such details!

[mr_mitm]

Could an animal have several hearts?

[djtriptych]

yes. I know octopuses and squids have three hearts. Just looked it up and it seems no mammal has more than one heart.

[joecool1029]

I do wonder if those animals have things like valves in their veins, as I understand it if the circulatory system wasn't as complex as it is, heart would have to pump a lot harder to move the volume it does. This isn't an area I know much of anything about, I just know veins have valves and can expand and contract to different stimuli much as a heart can... so even though mammals have one heart it's not like the rest of the system is a static not helping to pump blood.