He was a looker, but alas, never a player.

The rare diademed sifaka lemur was "an exquisitely beautiful creature," his fur a rich copper color with black highlights, his face ringed in soft white fur, said Anne Yoder, the director of the Duke Lemur Center.

He was the only one of his kind in captivity outside Madagascar, and though captured for breeding, a suitable mate was never found.

He died Jan. 21 at the university's center off Erwin Road at age 19.

"To see him was to be enchanted by him," Yoder wrote on the center's blog, "and for those who cared for him day in and day out, he was a vivid presence."

Duke's center is the largest sanctuary for lemurs, ancient relatives of monkeys, apes and humans.

For millions of years, lemurs flourished on their native island of Madagascar, about 250 miles from Africa's southeast coast. Since humans have settled there, nearly a third of the lemur species have become extinct.

There are perhaps 6,000 diademed sifakas left, said Charlie Welch, the center's conservation coordinator. He helped capture Romeo in 1993, holding a hammock-like net while former director Ken Glander darted the young lemur's mother high in the trees.

Romeo, his mother and an unrelated male were quickly brought to Durham to boost the center's breeding program.

But the sifakas are folivores, or leaf-eaters, with a complicated digestive system.

The adults soon died, and attempts to find a Juliet to join Romeo failed.

"All lemurs are fragile creatures, but sifakas are especially vulnerable," Yoder wrote.

During the years, the staff introduced other lemur species to Romeo's enclosure.

It never worked out for long.

"He just never seemed to like to share his space or food with others," said Niki Barnett, the education programs coordinator.

So Romeo spent a lot of his time at the center alone, "which was unfortunate," said Welch.

He liked his human caretakers, though, and would raise his arms for them to scratch him.

"You can imagine going in and scratching a lemur every day; you get kind of attached," Welch said last week. "It's really heartbreaking when a species doesn't work out in captivity, but you don't know until you try."

Romeo was believed to be suffering some digestive difficulties.

The cause of his death is not yet known.

"His long life is a testament to the remarkable care that he received from the DLC staff over the years," Yoder wrote. "We will miss our beautiful boy."