Manatee Dies After 'High-Intensity' Sex with Brother at Florida Aquarium

A captive manatee in Florida is dead, but his demise is one whale of a tale -- basically, poor Hugh the manatee had rough sex ... with his brother, Buffett. Yes, it was death by buffett.

The deadly sex went down at the Mote Marine Laboratory and Aquarium in Sarasota, with necropsy results revealing Huge, a 38-year-old manatee, died as a result of "high-intensity" sex with Buffett.

The necropsy report from the USDA, first published by ABC7, says Hugh's fatal injury was a 14.5-centimeter rip in his colon, which was caused by a sexual encounter with his larger brother.

The USDA says the aquarium observed high-intensity sexual behavior between the adult male manatees back on April 29, which included Buffett anally penetrating the smaller Hugh.

Following their first encounter, researchers found blood in Hugh's colon, but apparently, the 2 manatees kept going at it throughout the day ... with only occasional rest periods.

Eventually, Buffett tired after one last time penetrating Hugh and swam away -- however, Hugh was unresponsive at the bottom of the pool, and died.

While the USDA says the aquarium failed to protect Hugh before his death, the facility is defending its actions.

The aquarium says sex between Hugh and Buffett was natural and they were mutually seeking interactions on the day Hugh died.

The facility says Hugh showed no obvious signs of discomfort or distress ... and veterinarians directed handlers to try to distract the manatees from sex rather than physically separate them for fear of causing stress and anxiety.

Hugh and Buffett lived together for 27 years in the same pool, and were the only manatees in the aquarium.