By Bob HowardAssignment, BBC World Service
Getty ImagesGuillermo Otta Parum has been fishing in the Bolivian Amazon his whole life, for more than 50 years.
At first, Guillermo was catching native fish, such as the various kinds of catfish which inhabit the river.
But then a giant freshwater fish arrived, known locally as paiche or Arapaima gigas, to give it its scientific name.
“I thought this creature was a water snake, that it would attack everything, that eating it would be bad for you, that it might be poisonous,” he recalls.
In fact, it is one of the biggest freshwater fishes in the world, growing up to 4m in length and weighing 200kg (440lb) or more.
It is estimated that every year, the paiche spreads another 40km deeper into the rivers of the Amazon basin.
Federico Moreno, director of the Beni Autonomous…
