One of the Georgia Aquarium's prized whale sharks died Thursday night — the second death of a popular exhibit animal at the world's largest aquarium in 10 days.
Ralph, one of four whale sharks at the year-old aquarium, stopped swimming Thursday afternoon and died about 9:30 p.m., aquarium spokeswoman Donna Fleishman said.
The cause of death was not immediately determined. Aquarium executive director Jeff Swanagan said a necropsy would begin on Friday.
"Recently, he has not been eating well and has had some unusual swimming patterns," Fleishman said. The aquarium staff moved the 22-foot shark to another part of the tank after he stopped swimming and immediately began trying to revive him, but he died eight hours later, Swanagan said.
Ralph and Norton, the aquarium's other male whale shark, arrived in June 2005 from Taipei, Taiwan, where they had been destined to become seafood. They were joined a year later by two females, Alice and Trixie, in their 6-million-gallon tank.
They are the only whale sharks on display outside of Asia.
"The entire staff is saddened by what has happened," said Swanagan. "Sometimes nature deals you back to back deaths."
Teen had been tested earlier
Whale sharks are the world's largest fish, growing more than 50 feet long.
Ralph was considered a teenager. He measured 22 feet at his last examination by scientists two months ago. Swanagan said there was no sign of trouble in what was Ralph's third exam. Norton has been examined twice and Alice and Trixie once each.
During the Nov. 6 examination of Ralph, a hose pumped a liquid anesthetic into the water around Ralph's head — making him nearly unconscious for the two-hour checkup.
Once he was under, veterinarians from the aquarium and Mote Marine Laboratory in Sarasota, Fla., took blood samples to test the adolescent shark's hormone levels and studied the inside of his mouth and gills to learn more about how he digests food. They took DNA samples and used an ultrasound machine, with a small, portable computer screen, to check on his internal organs. They also measured him to track his growth.
Beluga whale euthanized
Gasper, one of the Georgia Aquarium's five beluga whales, was euthanized Jan. 2 after months of declining health.
The 17-year-old Gasper had been ill before arriving at the aquarium in October 2005. His health deteriorated further over the past few weeks. That led the aquarium's medical team to put him to death humanely, aquarium officials said.
More than 3 million people have visited the Georgia Aquarium since it opened in November 2005 — far outpacing attendance predictions.
The aquarium is considered the world's largest, with roughly 100,000 fish and more than 8 million gallons of water.