Species Fact Profile: West Indian Manatee (Trichechus manatus)

 West Indian Manatee

Trichechus manatus (Linnaeus, 1758)

Range: Coastal Waters in the Gulf of Mexico, Caribbean, and Central and northern South America
Habitat: Shallow Coastal Waters, Rivers, Estuaries; Move back and forth between saltwater, brackish, and freshwater habitats
Diet: Sea Grasses and other Aquatic Plants
Social Grouping: Primarily solitary, but will form breeding herds or aggregate around resources such as food or warm-water sources in the winter
Reproduction: Breed in mating herds, in which several males may congregate around females and compete for access.  Single calf (rarely twins) born after gestation period of 12-14 months.  Male provides no parental care.  Calf remains with female until weaned at 2 years.  Males sexually mature at 3-4 years, females at 3-5 years old
Lifespan: 50-60 Years (record approaching 70)
Conservation Status: IUCN Endangered, US Endangered Species List - Threatened

• Body length 2.7-3.5 meters (up to 4.6 meters), weigh 200-600 kilograms, with females usually larger than males.  Fully aquatic, with flipper-like forelimbs and no hindlimbs, instead having a large, spatula-shaped tail
• Gray skin is nearly hairless (with whisker-like vibrissae being especially prominent on the face), sometimes covered with algae or barnacles.
• Like elephants (some of their closest relatives), manatees have prehensile lips/snouts (though not trunks), as well as rows of molars which are constantly worn-down and replaced as manatees feed on plant matter.  They will sometimes pull themselves partially out of the water to feed on plants growing near the shore
• Manatees are the only mammals to have fewer than 7 neck vertebrae, having 6 instead
• Unlike many other aquatic mammals (and despite their rotund appearance), they have very little body fat, meaning that they cannot warm themselves in cold water.  This largely limits them to subtropical water.  This is the northernmost of the living manatee/sea cow species.  In the northern parts of the range, they frequently seek out artificial warm-water sources, such as power plants, to take advantage of the heat
• Occasionally wander far from their range.  Manatees have been spotted as far north as Massachusetts and as far up river systems as Memphis, Tennessee
• Two subspecies - the Florida manatee (T. m. latirostris) and the Antillean, or Caribbean, manatee (T. m. manatus)
• One of the primary threats (especially in US coastal waters) is collision with motorboats, estimated to be responsible for a third of all manatee deaths.  Many living manatees can be identified by researched by the scars and other injuries that they carry from boat collisions 
• Also susceptible to poisoning from consumption of toxic algae from red tide blooms
• No natural predators, but historically this species was hunted for meat, resulting in its absence from some parts of its range, especially in the Lesser Antilles
• Manatees were considered a possible origin for the myths of mermaids, especially when females nurse their young from their human-like breasts at the surface of the water.  Manatees were observed in such poses by Christopher Columbus during his expeditions to the Caribbean.  The order to which they belong, Sirenia, is named after the sea nymphs of Greek mythology