Georgia Aquarium has lost its second Whale shark in five months.
Officials at Georgia Aquarium in Atlanta, USA, confirmed today that their second Whale shark, named Norton, had to be euthanised after months of illness.
Five months ago, Norton's companion, Ralph, died following the application of a chemical to the water to cure an outbreak of leeches.
After months of illness, Norton's health began to deteriorate dramatically and last week he started to stop swimming. The Aquarium's husbandry and veterinary team took a blood sample, which confirmed his ill health.
The shark was placed on 24-hour watch and by Wednesday had stopped swimming and was resting on the bottom. Divers placed Norton on a stretcher, where further blood tests were undertake.
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"After every option had been exhausted to improve Norton's health, the team made the decision to humanely euthanise him," the Aquarium said.
Jeff Swanagan, the President and Executive Director of Georgia Aquarium, said in a statement: "During the last few months, Norton stopped eating and started to show erratic swimming behaviour.
"In response, exhaustive diagnostic tests were conducted by husbandry and veterinary staff. Supplemental care was provided to Norton, and the Georgia Aquarium team was encouraged and hopeful his condition would improve."
NecropsyA nine-hour necropsy of the dead shark showed that the fish weighed 1376 kg/3029 lbs when he died and measured 6.52 m/21'5", but the Aquarium claims that the gross necropsy has not revealed any immediate findings indicating the cause of his decline in health.
The Aquarium said in a statement: "The Georgia Aquarium believes that the decline in the health of both Norton and Ralph, the whale shark that died in January 2007, is related to their inappetance.
"During the necropsy of Ralph, findings showed that he had an atypical stomach, which was thin-walled and perforated; Norton s stomach appeared normal.
"Studies will continue to see if there is a link between their inappetance and a series of treatments used in 2006 to manage parasites in the Ocean Voyager exhibit, or if there is another cause.
"The treatment is commonly used in both home and professional aquariums and was used in a conservative manner. As a precaution, the Aquarium stopped using this treatment after the loss of appetite was observed."
The two female Whale sharks, Alice and Trixie, acquired after the problem, and the two acquired last month, Taroko and Yushan, were not exposed to the treatment and are reportedly "eating their complete diet and exhibiting normal behaviour".