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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
Spotted on May 24, 2014
Submitted on May 24, 2014
69 Comments (1–25)
Thnx James! Great guess too! Poor coot :(
Awesome shots Hema.....I am guessing American Coot by the protruding foot! Superb!
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.
http://www.defenders.org/american-alliga...
Beautiful
Congratulations Hema.
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
Really nice spotting, congrats!
thanks for your kind and encouraging words, Suz and outside girl :)
many congrats Hema on amazing spotting of the day!
Way to go, Hema ... congratulations!
Thank you so much, Adarsha, Dilan and Rob :)
Congratulations Hema! Very nice spotting!
Congrats Hema
Congratulations Hema Shah!
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!
Congratulations Hema!
Congratulations Hema. A very well deserved SOTD.
Congrats on your SOTD! when you were at merritt island did you get to see the scrub jays and the mute swan at viera?
thanks , Sukanya .
Thanks, Cindy.
Congratulations.
Congratulations!!!
Thanks Tom :)
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. :)