ATLANTA - Early results from a necropsy performed on a whale shark that died at the Georgia Aquarium this week produced no conclusive findings on the cause of death, aquarium officials said late Thursday.
Norton on Wednesday became the second whale shark -- the world's largest fish -- to die at the aquarium since January.
In January, Ralph, a whale shark who along with Norton was one of the aquarium's first stars when it opened in 2005, died from peritonitis, an infection in his abdomen.
Aquarium officials said Norton, like Ralph, had stopped eating in recent months and swam erratically. Early Wednesday, he settled to the bottom of the aquarium's centerpiece six million-gallon Ocean Voyager tank.
He was euthanized after attempts to restore his normal functions failed, aquarium officials said.
Norton weighed 1,373 kilograms and measured 6.5 metres long.
According to the aquarium, the necropsy showed that Norton's stomach was normal. Ralph's had been abnormally thin and perforated -- possibly from a feeding tube used to feed him when he stopped eating.
The aquarium has said a chemical used in 2006 to clean the sharks' tank may have contributed to Ralph's loss of appetite, but that it's too early to say whether Norton's was caused the same way. The routine since has been changed.
Santucci said it would have been a surprise if the early necropsy results had provided much of a clue in Norton's death. Full results are expected to take several months.
"You literally have to wait for science and nature to take its course," Santucci said.
The Georgia Aquarium, the world's largest, is the only facility outside Asia to display the huge fish.
