Video courtesy: the State Archives of Florida, USA
The title of this video: “Florida Silent Sirens: Manatees in Peril” and was filmed during 1980s
The caption of the video states: “This is an excellent film about the plight of the endangered manatee. It is narrated by Leonard Nimoy and is full of beautiful underwater photography. It shows tracking by radio collar, injured manatees and manatee interaction with people”.
The following review is the responsibility of Dr. Abdel Rahman El Gamal, Founder of the video channel
Introduction: The Florida manatee (Trichechus manatus) is a marine mammal which is also known as “West Indian manatee” or North American manatee. Manatees are occasionally called sea cows as they are similar to cows on land. Manatees belong to the family Trichechidae. This manatee is the largest, fully aquatic surviving member of the aquatic mammal “order Sirenia”. The lifespan of the manatee is 50-60 years in the wild. It is known that manatees have good long-term memory and they demonstrate task-learning abilities similar to dolphins.
Habitats: The primary habitat of this manatee species is the warm Florida coastal waters which provide wintering refuges for manatees in natural warm water springs. They also are attracted to the warm water outflow from power plants. In summer, some individuals migrate as far north as the Carolinas or as far west as Louisiana.
Description: The Florida manatees, Florida’s state marine mammal, are large and bulky aquatic mammals that are grayish brown in color and have thick, wrinkled skin. Their front flippers help them steer, or sometimes crawl, through shallow water. They also have powerful, spatula-shaped tails that help propel them through the water. Despite their small eyes and lack of outer ears, manatees are thought to see and hear quite well. Manatees may live around 50 years old.
Manatees have four rows of cheek teeth, which are not clearly differentiated into molars and premolars. Manatee teeth are continually replaced throughout the manatee’s lifetime with new teeth growing at the rear as older teeth fall out from farther forward in the mouth. At any given time, a manatee typically has no more than six teeth in each jaw of its mouth.
Manatees have a simple stomach, but a large cecum, in which they can digest tough plant matter. In general, their intestines have a typical length of about 45 meters, which is unusually long for animals of their size. Manatees are the only animal known to have a vascularized cornea.
On the average, an adult manatee measures up to 4.0 meters long, and weigh as much as 590 kilograms with recorded measures beyond the mentioned values; females that tend to be larger and heavier have two teats, one under each flipper. A manatee’s lungs are 2/3 the length of its body.
Feeding habits: Manatees are herbivores, with a diet consisting mostly of sea grasses and freshwater vegetation. They are known to eat over 60 different freshwater (e.g. floating hyacinth, pickerel weed, alligator weed, water lettuce, hydrilla, water celery, musk grass, mangrove leaves) and saltwater plants (e.g. sea grasses, shoal grass, manatee grass, turtle grass, widgeon grass, sea clover, and marine algae). An adult manatee will commonly eat up to 10%-15% of their body weight (about 50 kg) per day which requires the grazing for up to seven hours a day. Manatees have been known to eat small amounts of fish from nets.
Manatees use their flippers to “walk” along the bottom whilst they dig for plants and roots in the substrate using the flippers to scoop the vegetation toward the manatee’s lips which are used to tear the ingested plants and the process is completed by the ridged pads located on the roof of the mouth, bearing in mind that manatee does not have front teeth. Their divided upper lip provide them with high flexibility to grasp and take in aquatic plants.
Because of their feeding habits and like other grazing animals, Florida manatees play an important role in influencing the plant growth in their habitats.
