In the past, manatees have often been associated with slow-wittedness. In 1902, a famous British anatomist likened a manatee brain to that of an idiot.
For many years scientists assumed manatees lacked intelligence due to their small brain size, slowness, and clumsiness. Despite having the lowest brain size to body ratio of any mammal, manatees are very smart. But they are unusual in their physiology, physical composition and brain organization, according to studies of Florida manatees done over the last 10 years.
For example, neuroscience Roger Reep at the Univeristy of Florida uses neuro-technology to understand the intelligence of the manatee. While biologists have often associated brain size to survival, Reep says the small size of the manatee's brain has little or nothing to do with intelligence. The manatee's body proportions are probably due to simple evolution.
Reep suspects, "rather than manatees brain being unusually small for its body, the situation may be the other way around." Its large body allows it to keep warm in the water, despite struggling with a slow metabolism. Their hefty body also contains their large digestive system, which is necessary to process the large portions of sea grass and vegetables manatees eat.
Manatees are unique for other reasons. They have a heightened sense of touch and use thousands of bristly facial hairs which are called vibrissae. These vibrissae can be linked with 50 to 200 nerve fibers. Vibrissae are unlike normal hair fibers, each vibrasse is a finely calibrated sensory device. Each of its follicles are surrounded by a blood filled pocket or blood sinus.
Of these over 2,000 facial vibrassae, 600 of them are in a so-called oral disk, which is a circular region between the mouth and nose. The manatees oral disk is used much like an elephants trunk, to grasp and explore objects. Manatees use bristles on the oral disk and the upper lips to detect subtle differences in the grooves and ridges on an underwater panel. When a manatee was tested by a team of researchers in Germany, the results showed that the manatee was able to distinguish differences as small as 0.05 millimeters.
Despite the fact that manatees are viewed as unattractive compared to dolphins, whales, or sea otters, they are still majestic aquatic sea creatures who are well adapted to their environment.
Although manatees may appear like lazy creatures, appearance can be deceiving. Manatees are smart and beautiful sea animals. They have adapted and evolved. Astute observers of science realize brain size does not always reflect on intelligence.
[Source: National Wildlife Federation]