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American Alligator

Alligator mississippiensis


While most reptiles have 3-chambered hearts, the heart of alligators, and all crocodilians, has 4 chambers, a trait shared with mammals and birds. The advantage of a 4-chambered heart is that oxygenated blood and deoxygenated blood are separated, which results in more efficient respiration needed for the high metabolism of endothermic (warm-blooded) animals, and enables different pulmonary (lung) and systemic blood pressures, but is seemly over-complex for ectothermic (cold-blooded) crocodilians. The single ventricle of the 3-chambered reptile heart allows some mixing of oxygenated blood with deoxygenated blood, which may help regulate their metabolic state. Crocodilians have evolved a shunt between the left and right aorta (immediately above the ventricles) to facilitate the mixing of oxygenated and deoxygenated blood. Crocodilians also have a valve in the pulmonary artery that, when closed, forces deoxygenated blood to recirculate through the left aorta, which increases mixing. This increased mixing helps crocodilians transition to a lower metabolic state, and enables them to dive for extended periods. Some scientists have hypothesized that the complex heart structure of crocodilians might indicate that they evolved from endothermic (warm-blooded) ancestors.


Viera Wetlands

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69 Comments (1–25)

Hema 7 years ago

Thnx James! Great guess too! Poor coot :(

James McNair
James McNair 7 years ago

Awesome shots Hema.....I am guessing American Coot by the protruding foot! Superb!

Hema 7 years ago

i heard a lot of bellowing in the wetlands. I would not have known those were alligators ,unless a naturalist had not pointed that out.
Although alligators have no vocal cords, males bellow loudly to attract mates and warn off other males by sucking air into their lungs and blowing it out in intermittent, deep-toned roars.

bg11a1 7 years ago


Sckel 7 years ago

Congratulations Hema.

Hema 7 years ago

Thank you my friend.

Hema your alligator rock´s :-)
Congrats on the well deserved SOTD my friend and thanks for sharing your awesome wild encontours with us

bg11a22 7 years ago

Really nice spotting, congrats!

Hema 7 years ago

thanks for your kind and encouraging words, Suz and outside girl :)

outsidegirl0 7 years ago

many congrats Hema on amazing spotting of the day!

suzmonk 7 years ago

Way to go, Hema ... congratulations!

Hema 7 years ago

Thank you so much, Adarsha, Dilan and Rob :)

Adarsha B S
Adarsha B S 7 years ago

Congratulations Hema! Very nice spotting!

RobThacker 7 years ago

Congrats Hema

Dilan Chathuranga
Dilan Chathuranga 7 years ago

Congratulations Hema Shah!

Hema 7 years ago

Thanks Jamie, Mark and Satyen! :)
Jamie, i did not see the crested caracara or the mute swan,unfortunately.
But i did see the one scrub jay and it was a treat when it flew almost 2 ft away and sat on a tree for a long time.i took a walk in the scrub jay habitat. is there a way out?! The path seemed endless!

Wild Things
Wild Things 7 years ago

Congratulations Hema!

Mark Ridgway
Mark Ridgway 7 years ago

Congratulations Hema. A very well deserved SOTD.

jamiewgoodspeed 7 years ago

Congrats on your SOTD! when you were at merritt island did you get to see the scrub jays and the mute swan at viera?

Hema 7 years ago

thanks , Sukanya .

Hema 7 years ago

Thanks, Cindy.

SukanyaDatta 7 years ago



Hema 7 years ago

Thanks Tom :)

Hema 7 years ago

Thanks so much Karen!! A big surprise for me and I am totally delighted! Project Noah has enriched my life beyond words and I wish the project Noah team (administrators and spotters), happiness and success. :)

Spotted by

Florida, USA

Spotted on May 24, 2014
Submitted on May 24, 2014

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