Manatees Research Paper

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Chris Chapman Dr. Karen Keane-Hines Anatomy &Physiology II MANATEE Long ago manatees were mistaken for mermaids or sirens-luring sailors to their deaths on rocky shores. So the order of these marine mammals has been named, Sirenia. There are five species: Amazonian, West African, and West Indian with two sub-species the Florida and Antillian Manatee. All have front flippers and a solid, flat, paddle shaped tail. Another related species, the Dugong, has a fluked tail. One species, the Stellar’s Sea Cow, was hunted to extinction in 1768-only 27 years after it was discovered. It was the largest and the only manatee species to live in sub-Arctic waters. They originated about 45-50 million years ago and their closest…show more content…
Their lungs lie across the arched ribs along the full length of their vertebra, almost to their anus, instead of along its rib cage (ventral) like most mammals. This helps with buoyancy and balance. Each long, wide but thin lung has its own cavity with its own diaphragm. Scientists don't know if they can function independently, but they do know that manatees can have a severe infection in one lung and be healthy in the other lung. This helps with buoyancy and balance. When they breathe-only through their nostrils, they can exchange 90% of the air in their lungs with each breath, compared to a human who only exchanges about 10% of their air. They may need to breathe every 30 seconds during strenuous activity but can stay submerged for up to 20 minutes. Their muscles lack the density of myoglobin (muscle hemoglobin) that is typical of other diving mammals. This trait contributes to their relatively short (8-15 minute) and shallow (10-20 feet) dives compared to seals and dolphins, however they do swim like dolphins and seals in a dorsoventral fashion as opposed to side to…show more content…
deep) off the coasts of the Gulf of Mexico all the way down to Brazil, in the Amazonian River Basins, around the islands of Cuba, Haiti and Puerto Rico, as well as along the central west and east coasts of Africa, up the Nile and down to Madagascar. The West Indian/Florida manatees currently inhabit the warm sub-tropical waters along the coast of Florida (as far north as the Carolinas and west along the coast of Louisiana and Texas). Though their range is quite large, manatees today exist in only a few small populations due to centuries of hunting them for meat and hides, coastal development and boating, and environmental changes. It is currently estimated that there are only about 2,200 manatees remaining in the US. They have no natural enemies except man and power boats which are responsible for most manatee deaths- (in 1990, 218 manatees or 12 % of the total population were killed by boats), though the red tide (toxins released from the bloom of dinoflagellates) of 1982 and1996 killed over 15% of the population. It is suspected that environmental pollutions create disease vulnerability in marine mammals with manatees being no exception. An example is when 10,000 seals died in 1988 in Denmark and Sweden from viruses related to canine distemper. High concentrations of PCB’s were detected in necropsies of these seals, presumably from the water and fish they ate. Other threats include accidental

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