BANGKOK - A 25-year-old Thai sea turtle died from blood poisoning on Tuesday, never recovering from an operation to remove 915 coins from her stomach, thrown into her pool for good luck, veterinarians said.

The green turtle named Omsin, or "piggy bank", underwent a seven-hour operation this month to remove 5 kilograms of coins which she had mistaken for food.

But Omsin, who lived at a conservation center in Chonburi, east of the Thai capital Bangkok, was rushed into intensive care on Sunday night, breathing too slowly.

She received an emergency operation on Monday, after which she went into a coma.

Her fate had preoccupied Thais, who cherish turtles as a symbol of longevity, and the vets had urged people to pray for her recovery.

"Her cause of death is blood poisoning," one of the vets said.

The vets also said they would perform an autopsy on Omsin as a case study, which would benefit the treatment of turtles in the future.

"She is our teacher," one vet said.