The Florida manatee (Trichechus manatus
latirostris) is found primarily in the Florida
peninsula, but can occasionally be sighted as far
north as Virginia and west to Mississippi. The
Antillean manatee (Trichechus manatus manatus)
shows a patchy distribution, including northeastern
South America, southern Texas, Mexico, and
the Caribbean. Trichechus senegalensis, theWest African
manatee, can be found on the west coast of
Africa from Senegal to Angola. The Amazonian
manatee, Trichechus inunguis, is found throughout
the Amazon river drainage basin.
The species are distinguished by their geographical
distributions, and while they are physically
very much alike, some differences exist. Manatees
all exhibit a streamlined body, full around the
middle with no visible neck, tapering to a paddleshaped
tail used for propulsion. They have two
small pectoral flippers on their upper bodies that
are used for steering and bringing food to the
mouth. The lips are long and flexible, and help in
funneling plants into their mouths. Manatees are
grayish-brown in color and have sparse, bristly
hair scattered thinly over their torsos. They have
molars at the back of their mouths, and unlike
most other mammals, as the front molars wear
down they are continually replaced by new teeth
from the back of the mouths. Adult West Indian
andWest African manatees average about ten feet
in length and weigh approximately 800 to 1200
pounds. Amazonian manatees are smaller, shorter,
and more slender, averaging about eight feet in
length and less than eight hundred pounds.
Adapted for the Aquatic Life
Streamlined bodies and flippers are ideal for the
aquatic life of a manatee. They are agile and typically
cruise in search of food at speeds of two to six
miles per hour, but can swim as fast as fifteen
miles per hour. While they have been sighted diving
to depths of about thirty-three feet, they primarily
forage for food no deeper than ten feet.
Manatees can stay underwater for up to twenty
minutes, but typically surface every two to three
minutes for air.
Manatees spend most of their day foraging for
aquatic plants and will consume between 4 and
9 percent of their body weight in wet vegetation
daily. The animals are nonaggressive and nonterritorial
and spend the rest of their time traveling,
investigating objects, and socializing. Manatees
are considered semisocial, and the typical
social unit is a female and her calf; however, congregations
of up to two hundred individuals can
be found near warm water sources such as power
plant outfalls and hot springs, especially during
winter months.
Male manatees are sexually mature at about
nine to ten years of age, and females at about
seven to eight years. Mating takes place in the
water, and the female is accompanied by, and
mates with, several males. Gestation takes about
twelve months; the newborn calf measures about
four feet and weighs sixty to seventy pounds.
Calves remain close to their mothers for up to two
years. The calf is dependent on its mother for nutrition,
and for learning about feeding and resting
areas, migratory routes, and warm water refuges.
It is believed that manatees can live to sixty years
in the wild; however, habitat destruction and injury
by boats and fishing lines are seriously endangering
manatees worldwide.
Classification:
Kingdom: Animalia
Subkingdom: Bilateria
Phylum: Chordata
Subphylum: Vertebra
Class: Mammalia
Subclass: Eutheria
Order: Sirenia
Family: Trichechidae (manatees)
Genus and species: Trichechus manatus (West Indian manatee, with subspecies latirostris, the Florida manatee, and
manatus, the Antillean manatee); T. senegalensis (West African manatee); T. inunguis (Amazonian manatee)
Geographical location: Florida, Caribbean, and northern South America; West Africa; Amazon River basin
Habitat: Warm tropical and subtropical water, including shallow coastal waters, estuaries, and rivers
Gestational period: Approximately twelve months
Life span: Twenty-eight years in the wild; fifty to sixty years in captivity
Special anatomy: Flat, paddle-shaped tail; two pectoral flippers; nasal openings at the top of the snout; large,
flexible upper lip equipped with vibrissae attached separately to nerve endings and each with its own blood
supply
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