The internal anatomy of the manatee
has been well understood for over a hundred years, but for many organs and organ
systems, modern histological and histochemical techniques need to be applied to
understand their function or physiology.
Manatee senses are well-developed,
especially hearing which has been measured as a range exceeding that of humans
in the low frequency range. Touch, taste, sight, and smell are all important
senses for the manatee and appear to be well-developed. Further studies are in
progress to determine ranges of sensitivity.
Digestion in manatees typifies the hindgut
digesters, herbivores in which most cellulose breakdown occurs in the large
intestine. The horse is another hindgut digester.
Kidney function in manatees has not been
studied, but most scientists believe that manatees can exist for some time
without fresh water, but that the animals must have access to freshwater
periodically to survive. Preliminary studies suggest that manatee kidneys can
produce a reasonably concentrated urine.