For more than two years, an Atlantic bottlenose dolphin caught the imagination and concern of the humans who watched him caper in the lake behind the Wagon Wheel Flea Market.
His unusual residency ended last August.
Scientists are still uncertain why the dolphin died. He was young. He was not underweight. He did not appear sick. There were no external wounds. A necropsy failed to shed any light on the question.
"We really couldn't tell. It was too decomposed," said Chris Koberna, head of animal care at the Clearwater Marine Aquarium. "It's still a gray area. It definitely died quickly."
One possibility, Koberna said, is that the animal could have choked on something.
"It was just a shame," Koberna said. "For the two years we have been monitoring him, he had been doing well."
The dolphin, who had no name but came to be known as the Wagon Wheel dolphin, first drew attention a little more than two years ago when people noticed him playing in the lake.
Worried that he'd become trapped, they notified scientists, who felt he could escape the way he'd entered, so they left him alone for a while.
Later, when he developed a skin condition perhaps because of the water's low salt content, they encouraged him to leave. But the dolphin kept outsmarting the humans as they tried to guide him out of the lake. Finally, they decided to leave him and regularly check on him to make sure he was all right.