Police in Brazil are investigating the disappearance of seven rare albino alligators from a university zoo in the western state of Mato Grosso.
By Gary Duffy
BBC News, Sao Paulo
One theory is that they may have been stolen to be sold abroad.
The animals, said by officials to be worth around $10,000 (£5,070) each, have no skin pigment and their eyes are a distinctive pink.
Most of albino alligators born in the wild do not survive because their skin colour makes them vulnerable to attack.
The seven alligators disappeared from the zoo at the Federal University in Mato Grosso, Brazil's TV Globo reported.
They were last seen when they were fed on New Year's Eve, but they were missing when a zoo official went to feed them again on Wednesday morning.
Police say there was no sign of a break-in at the zoo which contains more than 800 animals spread across 11 hectares (27 acres) hectares of parkland.
The alligators were said to be young with an average age of around two years, and only one albino alligator is now left at the zoo.
Police say the rarity of the alligator will make the investigation difficult as the people involved in the illegal trading of such rare species are very secretive.
The apparent theft also highlights a wider problem.
Animal rights activists say Brazil accounts for 10% of the world's illegal trade in animals, mainly parrots and other birds, which are often sold in Europe and the United States.