Thursday, January 20, 2011
January 20, 2011 : Manatee
Manatees (family Trichechidae, genus Trichechus) are large, fully aquatic, mostly herbivorous marine mammals sometimes known as sea cows. There are three accepted living species of Trichechidae, representing three of the four living species in the order Sirenia: the Amazonian manatee (Trichechus inunguis), the West Indian manatee (Trichechus manatus), and the West African manatee (Trichechus senegalensis). They measure up to 3.6 metres (12 ft)), and have paddle-like flippers. The name manatí comes from the Taíno, a pre-Columbian people of the Caribbean, meaning "breast".
Half a manatee's day is spent sleeping in the water, surfacing for air regularly at intervals no greater than 20 minutes. Manatees spend most of the rest of the time grazing in shallow waters at depths of 1–2 metres (3.3–6.6 ft). The Florida subspecies (T. m. latirostris) has been known to live up to 60 years.
Manatees inhabit the shallow, marshy coastal areas and rivers of the Caribbean Sea and the Gulf of Mexico (T. manatus, West Indian Manatee), the Amazon Basin (T. inunguis, Amazonian Manatee), and West Africa (T. senegalensis, West African Manatee). A fourth species, the Dwarf Manatee (T. "pygmaeus"), was recently proposed for a population found in the Brazilian Amazon, although some believe it to be an immature Amazon Manatee.
They enjoy warmer waters and are known to congregate in shallow waters, and frequently migrate through brackish water estuaries to freshwater springs. Manatees cannot survive below 15°C (288 K; 60°F). Their natural source for warmth during winter is warm-spring fed rivers.