Why do squids need to have three separate hearts?
Since this is not my area of expertise, I searched Google under the key words "Squid anatomy hearts" to get these possible sources:
http://www.thewildones.org/Curric/squid.html
http://en.wikipedia.org/wiki/Squid
http://72.14.253.104/search?q=cache:nU60VQAr2pQJ:www.aqua.org/downloads/pdf/Outreach_Squid_Lab_Teacher_Booklet_Sept_2005.pdf+Squid+anatomy+hearts&hl=en&ct=clnk&cd=7&gl=us&client=safari
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.
I hope this helps. Thanks for asking.
Squids have three separate hearts because of their unique anatomy and physiological needs. Each heart serves a different function and helps the squid efficiently circulate blood throughout its body.
The main reason for having three hearts is because squids have a highly developed muscular structure called a mantle, which surrounds their internal organs and is responsible for pumping water through their gills. The first heart, known as the systemic heart, is responsible for pumping oxygenated blood to the body's organs and tissues. It is located near the base of the gills.
The second heart, called the branchial heart, is responsible for pumping deoxygenated blood to the gills, where it becomes oxygenated. This heart is located further back in the mantle, closer to the gills.
The third heart, called the accessory heart or auxiliary heart, is responsible for pumping deoxygenated blood to the two other hearts. It helps propel the blood in the right direction and provides additional pressure to ensure efficient circulation.
Having three separate hearts allows squids to maintain a constant supply of oxygenated blood to their organs, especially during periods of high activity when they require a lot of oxygen. Additionally, it helps them adapt to changes in their environment, such as diving to different depths where there may be variations in pressure and oxygen availability.
In summary, squids have three separate hearts to efficiently circulate oxygenated blood to their organs and tissues, as well as to adapt to their unique underwater environment.