The manatees of the Crystal River are Sirenians – an order of large aquatic mammals with stout bodies which look a bit like small whales and are said to be the source of the original mermaid myth.
Their considerable size, with a fully grown female reaching up to 4m in length and about 1500kg, means they have evolved without any natural enemies and have developed a rather slow and passive nature.
They get their name from “sirens”, the ancient term used to describe the sea nymphs and their captivating songs that lured sailors to their deaths in treacherous shallow waters.
Distantly related to elephants, but usually referred to as “sea-cows”, there are now only four species of sirenians still alive of the 35 that are known to have once existed – three of which fall in to the Manatee family, while the fourth is in the Dugong family.
A sub-species of the West Indian manatee species, the Florida Manatee is usually found in the shallow coastal waters around the state, but in summer can be spotted as far west as Louisiana and all the way up to the Carolinas on the east coast of the USA.
Solitary creatures that can live more than 70 years, manatees are the only aquatic mammal that is also an herbivore and they exist on a primary diet of sea grass, the pursuit of which consumes up to 8 hours a day, with a full grown adult consuming up to 10% of its body weight every day.
Contrary to what its rotund appearance might suggest, the manatee’s diet means that it is actually a really “lean machine” with virtually no fat or blubber to keep it warm when the water temperature drops in winter.
At water temperatures below 68 deg F the Florida Manatee simply cannot maintain its core body temperature and will die of cold stress unless it can find a source of warmth.
Which means that Kings Bay and its natural springs provide a perfect natural refuge for them.
If you are interested in learning more about this fascinating and rather enigmatic creature I would strongly recommend getting a copy of Roger Reep and Robert Bonde’s excellent book The Florida Manatee.