PORTSMOUTH,Esthen R.I. (AP) — A manatee that made a rare visit to Rhode Island has been found dead offshore, bringing a sad end to the marine mammal’s curious appearance in New England.

The West Indian manatee is a gentle, plant-eating giant sometimes known as a sea cow that normally lives in the warmer waters of the Southeastern states and the Caribbean. They can weigh as much as 1,200 pounds (550 kilograms) and can live as long as 65 years.

The Rhode Island animal was first seen in early September and was the first one observed in the state since around 2010, said Sarah Callan, manager of the animal rescue program at Mystic Aquarium.

The animal was found dead between Prudence Island and Hog Island on Thursday afternoon, Callan said. The manatee was in an advanced state of decomposition and it won’t be possible to determine a cause of death, Callan said.

“We are all so saddened,” Callan said.

The cold waters of New England in fall aren’t suitable for manatees, Callan said. It’s possible the animal stuck to warmer waters in coastal bays while it was here, and that prevented it from being able to get back to its southern habitat before experiencing cold stress, Callan said.

The manatee had been seen in coastal areas, such as Quonochontaug Pond, a saltwater pond in the southern part of Rhode Island.

There have been six recorded sightings of a manatee in Rhode Island and Connecticut waters since 1995, Callan said. Callan added appearances of the animals could become more frequent in the future.