Manatee Eyes Give Them Away

Manatees are endangered and thought to be vulnerable to the changing conditions in Florida waters.  But the tears of this "sea cow" may be an easy way to diagnose whether an individual animal is healthy or not. 

For many mammals, tears are the only way they have to protect their eyes from infection. Manatees produce thick tear films - possibly the thickest of any animal, according to Don Samuelson from the University of Florida. 

"The manatee is able to enter murky waters just rich with potential pathogens," Samuelson said. "For that reason, we think this very thick tear film, undoubtedly rich with antimicrobial components, serves to protect in areas that could otherwise be devastating."

Samuelson and his colleagues speculate that tear samples can offer a substitute for blood tests.  Some ophthalmologists already use tear analysis with their human patients, and veterinarians are beginning to adopt the practice as well, Samuelson said.

The manatee tears can be collected using a cotton swab, without having to remove the animals from the water.

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-- LiveScience Staff

Credit: Everglades National Park Photo