1/10/2015 seaworld.org/en/animal-info/animal-infobooks/manatee/scientific-classification/ PARKS KIDS SHOP ANIMALS CARE LANGUAGE Scientific Classification → Scientific Manatee Classification Scientific Classification Habitat & Distribution Physical Characteristics Senses Adaptations Communication Class Mammalia Behavior Diet & Eating Habits Reproduction Order Sirenia Birth & Care of Young 1. The living sirenians consist of three species of manatees and one species of dugong. Longevity & Causes of 2. The Greek name for this order is derived from the sirens of Greek mythology. Sirens were sea nymphs Death who lured sailors to their island with their mesmerizing songs. Conservation & Research Appendix Books For Young Readers Bibliography Sirenians are named for the sirens of Greek mythology. Family ­ Trichechidae And Dugongidae 1. All three species of manatees belong to the family Trichechidae. 2. The family Dugongidae includes the dugong found in the Indian and western Pacific Oceans. A second species, the Steller's sea cow was discovered in 1741 and hunted to extinction by 1768. This species lived primarily in the Commander Islands of the western Bering Sea. Genus, Species 1. Trichechus manatus, the West Indian manatee. There are two subspecies of the West Indian manatee: the Florida manatee (Trichechus manatus latirostris) and the Antillean manatee (Trichechus manatus manatus). These subspecies are distinguished by differences in cranial measurements and by their geographic distribution. 2. Trichechus senegalensis, the West African manatee. About the same size and shape of the West Indian manatee, the West African manatee differs in some important respects: position of the eyes, snout, and cranial bones. 3. Trichechus inunguis, the Amazonian manatee. The Amazonian manatee is the smallest of the manatees. Several physical characteristics distinguish it from the other two species. It lacks nails on its pectoral fins, and usually has whitish patches on its underside. Fossil Record http://seaworld.org/en/animal-info/animal-infobooks/manatee/scientific-classification/ 1/2 1/10/2015 seaworld.org/en/animal-info/animal-infobooks/manatee/scientific-classification/ 1. The fossil record of sirenians is incomplete, and the relationship between manatees and their ancestors is poorly known. Sirenian fossil records are incomplete and continue to be an area of study. 2. Even though the oldest known sirenian fossils were found in Jamaica (Prorastomus sirenoides), it is likely that sirenians originated in Eurasia or Africa. During the middle Eocene period (45 to 50 million years ago), the ancestors of manatees probably reached South America (Savage et al., 1994). 3. Studies using biochemical analysis of proteins show that the closest modern relatives of sirenians are elephants, aardvarks, and small mammals known as hyraxes. These four orders of mammals are sometimes considered "subungulates", meaning they may be evolutionary offshoots of a primitive ungulate (hoof) stock. The anatomical characteristics they share include the lack of a collar bone and the presence of nails instead of claws. Scientists once mistakenly thought manatees were closely related to walruses based on facial similarities (Reynolds and Odell, 1991). http://seaworld.org/en/animal-info/animal-infobooks/manatee/scientific-classification/ 2/2 1/10/2015 seaworld.org/en/animal-info/animal-infobooks/manatee/habitat-and-distribution/ PARKS KIDS SHOP ANIMALS CARE LANGUAGE Habitat & Distribution Scientific Classification Manatee Habitat & Distribution → Habitat & Distribution Physical Characteristics Senses Adaptations Communication Distribution Behavior Diet & Eating Habits 1. All living sirenians are found in warm tropical and subtropical waters (Nowak and Paradiso, 1983). Reproduction Birth & Care of Young Longevity & Causes of Death Conservation & Research Appendix Books For Young Readers Bibliography Manatees and dugongs are found in warm waters around the world. In the United States, manatees are most common in Florida waters. 2. The West Indian manatee was once abundant throughout the tropic and subtropical western North and South Atlantic and Caribbean waters. However, the manatee's numbers have been greatly reduced. Today, the West Indian manatee is listed as an endangered species throughout its range. The range of the Florida manatee is primarily peninsular Florida but extends as far north as Rhode Island. Manatees have been rescued near Houston, Texas, and Mississippi. Antillean manatees have a patchy distribution throughout the Caribbean, Mexico, and northeastern South America. The southern range extends through Central and South America to Brazil. 3. West African manatees range from Senegal to Angola, on the west coast of Africa. Amazonian manatees are the only species of manatee confined to fresh water. They inhabit the Amazon Basin, mostly in Brazil. They are uncommon or close to extinction in Peru, Ecuador, and Colombia. Habitat 1. The West Indian and West African manatees inhabit rivers, bays, canals, estuaries, and coastal areas rich in seagrass and other vegetation. They can live in fresh, saline (salt), and brackish waters. They move freely between extremes. http://seaworld.org/en/animal-info/animal-infobooks/manatee/habitat-and-distribution/ 1/3 1/10/2015 seaworld.org/en/animal-info/animal-infobooks/manatee/habitat-and-distribution/ West Indian manatees freely move between fresh, brackish, and saline waters. West Indian manatees may be found in any waterway over 1 m (3.25 ft.) deep and connected to the coast. They prefer waters with temperatures above 21°C (70°F). Florida manatees rarely venture into deep ocean waters. However, manatees have been spotted as far offshore as the Dry Tortugas Islands, approximately 81 km (50 mi.) west of Key West, Florida. West African manatees live in quiet coastal areas, large rivers, lagoons, and connected lakes, where the water temperature is above 18°C (64°F). 2. The Amazonian manatee is restricted to fresh water. They are most common in floodplain lakes and channels in white-water river systems with water temperatures ranging from 25°-30°C (77°-86°F). 3. The patchy distribution of manatees throughout all their ranges is due to their search of suitable habitat: plentiful aquatic plants and a freshwater source of water to drink. Migration 1. Florida manatees move into warmer waters when the water temperature drops below about 20°C (68°F). Manatee calves learn migration routes and the locations of warm water areas from their mothers. Historically, Florida manatees have migrated south into warmer waters during the colder months of the year. On the Gulf coast, manatees congregated at natural warm-water springs. On the Atlantic coast, manatees headed south of the Sebastian River. Today, power plant outfalls and other warm-water discharges are important winter destinations for many manatees. In Florida, more than 200 manatees congregate at some power plants during cold weather. These artificially heated sources have allowed manatees to remain north of their historic wintering grounds. Among the most important of the artificial warm-water discharges are the Florida Power & Light Company's power plants at Cape Canaveral, Fort Lauderdale, Port Everglades, Riviera Beach, and Fort Myers, as well as the Tampa Electric Company's Apollo Beach power plant in Tampa Bay, Florida (Van Meter, 1989). 2. In dry seasons, West African and Amazonian manatees migrate downstream or into lakes or deeper parts of a river. http://seaworld.org/en/animal-info/animal-infobooks/manatee/habitat-and-distribution/ 2/3 1/10/2015 seaworld.org/en/animal-info/animal-infobooks/manatee/habitat-and-distribution/ 3. One manatee known as "Chessie" traveled 3,220 km (2,000 mi.) from Florida to Point Judith, Rhode Island, and back in 1996. Chessie migrated further north and covered a greater distance than any manatee ever documented. Population 1. The Florida manatee census taken in January, 2000, found 2,222 individuals. The 1999 survey was 2,353. Scientists believe there may be as many as 3,000 manatees currently in the state of Florida. 2. Populations of all species of manatees have apparently declined over the past hundred years. These declines are due to such causes as hunting for their meat, destruction of their habitats, boating, pollution, and low reproduction rates. Antillean, Amazonian, and West African manatee populations are not known due to inadequate scientific research. http://seaworld.org/en/animal-info/animal-infobooks/manatee/habitat-and-distribution/ 3/3 1/10/2015 seaworld.org/en/animal-info/animal-infobooks/manatee/physical-characteristics/ PARKS KIDS SHOP ANIMALS CARE LANGUAGE Physical Characteristics Scientific Classification Manatee Physical Characteristics Habitat & Distribution → Physical Characteristics Senses Adaptations Communication Size Behavior Diet & Eating Habits 1. Adult West Indian and West African manatees average about 3 m (10 ft.) in length. Large individuals may reach lengths of up to 4 m (13 ft.). Average adult weights are approximately 363 to 544 kg (800- Reproduction 1,200 lb.). One particularly large Florida manatee weighed 1,655 kg (3,650 lb.). Females are generally larger than males. Birth & Care of Young Longevity & Causes of Death Conservation & Research Appendix Books For Young Readers Bibliography Adult West Indian manatees average about 3 m (10 ft.) and weigh approximately 363 to 544 kg (800 to 1,200 lb.). 2. Amazonian manatees are the smallest of all three species. They are shorter and more slender. The longest specimen