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12:45 ORDER SIRENIA - MANATEES. Phylum Chordata; Class Mammalia. The Florida manatee has been protected by law since 1893 and by the Endangered Species Act of 1973 - but only about 2000 still survive. There were 5 populations in the Order Sirenia.
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12:45 ORDER SIRENIA - MANATEES Phylum Chordata; Class Mammalia The Florida manatee has been protected by law since 1893 and by the Endangered Species Act of 1973 - but only about 2000 still survive.
There were 5 populations in the Order Sirenia. 1. West Indian - Trichechus manatus migrates from Brazil to Florida in the ocean, and often spends winter in warm rivers. 2. West African Manatee 3. Amazonian Manatee • Dugong - found in • Australia and Indonesia, • has a tail shaped like • a mackerel, only horizontal. 5. Stellar Sea Cow - hunted to extinction within 27 years of its discovery in 1741 in the Bering Strait
Manatees are related to the elephant through biochemistry and external features. The average manatee is 10 feet long and weighs ~ 1000 pounds. Calves are around 4 feet long and weigh ~ 60 pounds. These herbivores may eat 100 pounds of sea grass a day or 10 % of their total body weight. They have large lips to hold plants and replaceable back molars.
They like warm, shallow water and need fresh water to drink. Their constant eating helps clear navigational channels of water weeds. FWS However, by inhabiting rivers they encounter boats where 50% of their deaths are from human-related boating accidents. Many manatees are identified by their propeller scars.
Mammal characteristics: 1. whiskers (vibrissae) on snout used to rake in plants 2. mammary glands - cows nurse young for a year. The glands are located under the flippers. 3. live births - gestation period 13 months, produce one calf every 3-5 years. They do not reach sexual maturity until 5-9 years old and may live up to 60 years. 4. large brain , but poor vision 5. warm blooded with a 4 chambered heart 6. stomach has compartments and it ruminates
7. breathes air - may dive for 20 minutes 8. marine mammal tail - horizontal paddle 9. can produce a high-pitched whistle for communication They have no predators nor social structure and are not territorial. Herds have no leader and no permanent bonds are formed for mating.