The world's oldest female hippopotamus in captivity, Susie, has died at Adelaide Zoo at the age of 49, but is survived by her male partner Brutus who is now 52.
Zoos SA veterinarian David McLelland said Susie had far exceeded the average life expectancy for hippos, but had been humanely euthanased this week.
"Over the past few months, Susie had been suffering from a number of age-related conditions which our veterinary team were monitoring closely and treating," Dr McLelland said.
"Sadly, over the past few weeks, Susie's condition deteriorated and the veterinary team decided there was no further treatment that would improve her quality of life.
"To reach almost 50 is a good age for a hippo and a testament to the care provided to her over the years. Although saying goodbye to Susie was difficult, it was the right thing to do for her."
Susie was born at the end of 1967 and Brutus more than two years earlier, both at Sydney's Taronga Zoo.
They were moved to Adelaide Zoo together in 1975.
Veterinary staff said Susie mothered 17 calves and had six of them with Brutus.
They said the easiest way zoo visitors could tell the pair apart was by Brutus's larger head and Susie's hairy ears.
Generations of zoo visitors enjoyed hippos
Zoos SA chief executive Elaine Bensted said Adelaide was lucky to have the female hippo for so many years.
"In 42 years, she's probably seen over 10 million visitors at Adelaide Zoo so she really has been a part of our history and will be really sadly missed," she said.
She said the zoo had celebrated some important breeding achievements of recent times, which was happier news for the future.
"At Adelaide Zoo we've welcomed a critically endangered white-cheeked gibbon infant, a cheeky baboon baby and critically endangered golden lion tamarins," she said.
"And we have recently welcomed our adorable giraffe calves and cheetah cubs at Monarto Zoo."
After a post-mortem examination, the female hippo's remains will be donated to the University of Adelaide for medical research.
