Manatee

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Manatee

Sea monsters have long captured man’s imagination, and real animals are often tied to these myths. When Christopher Columbus sailed across the Atlantic, he sighted what he called a mermaid near the Dominican Republic in 1493. This was the first know sighting by a European of a manatee. He did make note that they were not as attractive as he had been led to believe. Even the name of their order ‘sirenia’ comes from the Latin word that represents sirens and mermaids. It is unknown how long a man has to be at sea before he confuses a sea cow with a woman.


Content List

1. Scientific & Common Names

2. Characteristics

a. Breeding

b. Behavior

3. History

4. Present Status

5. References


Scientific & Common Names

Kingdom - Animalia

Phylum – Chordata

Class – Mammalia

Infraclass - Eutheria

Order - Sirenia

Family - Trichechidae

Genus – Trichechus

Species – inunguis(Amazon), manatus(West Indian), senegalensis(African)

Common Names – Manatee, sea cow


Characteristics

Manatees, like their close relatives the dugong, are completely aquatic and never leave the water, although they are mammals and must breathe air. Their cylindrical bodies average 9-10 feet long and weigh anywhere from 800-1200 pounds. They have fleshy, paddle like flippers and tails which propel them through the water at an average of five miles an hour and a very short top speed of 15-20mph. They prefer shallow coastal waters, springs, or slow moving rivers. They will migrate great distances in the summer months, but always return to warm waters in the winter.


Breeding

Breeding can begin at the age of five and they only tend to have a single calf every 2-5 years. Gestation lasts a year and the nursing calf stays with its mother for 1-2 years. The 60-70 pound baby is born underwater and the mother must help it to the surface to take its first breath, but it can swim on its own within an hour. With a 60 year lifespan, a female can have between 10-20 offspring.


Behavior

Surfacing to breathe every 3-15 minutes, depending on their activity, manatees generally only lift their faces out of the water, leaving their bulk just below the surface. Manatees are herbivores and they graze on sea grasses and algae, consuming up to a tenth of their weight in a single day. They occasionally ingest fish or invertebrates along with the greases, but those are incidental by-catch and are not something the manatees seek out. They are gentle and slow moving, but have few natural enemies. Although not territorial, they live somewhat solitary lives. Even though they can be found in pairs or small groups, there is little socialization observed among them.


History

Like whales and dolphins, manatees are believed to have evolved from land mammals over 60 million years ago. Aside from dugongs, their closest living relatives still occupy the land – elephants and hyraxes. They had one other close relative, Steller’s Sea Cow, but they were hunted to extinction in the 18th century.


Present status

Manatees were included in the first endangered species list in 1967 issued by the US government alongside such iconic animals as the timber wolf, bald eagle, and the grizzly bear. Their tendency to rest near the surface often causes them great harm when they are struck by power boats. They are also vulnerable to fishing nets and other human debris. Natural threats are mostly environmental like algae blooms or cold weather snaps. All three species are considered vulnerable to extinction, along with the dugong. All species are protected from hunting or harassment, but their numbers are still declining and are expected to continue to decline.


References

Smithsonian National Museum of Natural History

Manatee Insanity: Inside the War over Florida's Most Famous Endangered Species by Craig Pittman

U.S. Fish and Wildlife Service

Manatees and Dugongs of the World (Marine Life) by Jeff Ripple

Ecology and Conservation of the Sirenia: Dugongs and Manatees (Conservation Biology) by Helene Marsh, Thomas J. O'Shea, John E. Reynolds III

Mermaids: The Myths, Legends, and Lore by Skye Alexander