SARASOTA, Fla. — Scientists say a manatee that swims in waters near Sarasota has given birth to rare twins.

The Herald-Tribune reports the manatee, Tomo-Bella, who has been observed by marine biologists since 1993, was spotted by an onlooker in a canal on Siesta Key this month with the twin calves.

According to a news release, the onlooker took video of the family and sent it to Mote Marine Laboratory, which confirmed the mother's identity.

Manatee twins are born between 1.4 and 4 percent of the time to Florida manatees.

Tomo-Bella has been documented with eight calves during the 23 years that scientists have been observing her.

Mote asks people who see the manatee with the twin babies to take photos, videos and provide location information — but don't disturb them.