How do manatees go to sleep?

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Swimming with manatees is an amazing experience. It is quite awesome to see and interact with a huge animal that is more interested in hugging humans than biting them. It is also thrilling and fun observing these aquatic giants lumbering through the water, taking naps and nursing their young ones. Like other animals, manatees have a full schedule of activities to undertake each day, including sleeping and resting, grazing and eating, traveling and socializing. Generally, manatees spend 10-12 hours of their day sleeping and resting, 8 hours grazing and eating, and about 4 hours traveling and socializing, or even eating and sleeping a little more.

Sleeping posture

When you arrive in Crystal River in the morning, you will find most manatees wide awake and active. Due to their low metabolism, the animals eat pounds of plants for several hours, enough to equal 10-15 percent of their body weight. For the next 4 or more hours, the manatees would continue to graze on the vegetation in their habitat until around noon. By high noon, a good number of the manatees would sink in the water to sleep. However, because manatees do not have gills for breathing when underwater, they suspend themselves upside down close to the surface so they can sleep and breathe at the same time. Manatees always sleep in an upside down position because as marine mammals they might die if they do not breathe as soon as necessary, although the manatees also may sleep with their backs patched on the sea bed.

Breathing intervals

To sleep, manatees typically lie on their backs or suspend themselves upside down in the water and get power naps between regular intervals of breathing. While the manatees are able to sleep in the water for up to 12 hours every day, they also are able to move to the water surface 3 times an hour to breathe during their sleeping or resting period. As they sleep, the muscles of their rib cage will relax to increase their lung volume, resulting in the manatees being gently carried to the water surface to breathe. Soon after taking in enough air, the rib cage muscles will contract to allow the manatee to easily sink back underwater. Manatees use this mechanism to move to and from the surface to breathe instead of having to swim actively up and down.

Unihemispheric sleep

Being marine mammals, the manatees have unihemispheric sleep, a type of sleep in which half of the animal’s brain rests while the other half stays active. The half that is active enables the manatee to move to the surface to breathe since manatees cannot truly sleep underwater when at the same time they need to breathe air. Humans sleep bihemispherically, with both halves of the brain rested during sleep. But for the manatees, it makes sense that they sleep unihemispherically because they need to come to the water surface every 20 minutes and a wakeful state is necessary to support the motor functions involved in the up and down movement.

Are you interested in seeing Florida manatees sleeping, resting or grazing? Would you like to swim and interact with these amazing sea cows? At Captain Mike’s, we have tailored our manatee tours to meet a wide range of interests and budgets. We ensure that our guests enjoy their time out in the water, find and interact with manatees, learn as much as possible about these gentle giants and go home with memories of a lifetime. For more information on how to plan for and go out on a thrilling and unforgettable manatee tour, visit the “Captain Mike’s Swimming With The Manatees” site.

Swimming with the Manatees boasts the best water adventure in Crystal River, Florida with lots of things to do for you and your family. For more information, contact us online, or call us at (352) 571-1888.

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