Catfish used to be common throughout Thailand, Cambodia and Laos.
Now they are so rare that the authorities have ordered that each one caught is tagged, weighed and released.
But they remain popular for their meat and often get caught up in the huge fishing nets which line the local rivers.
Their survival is also threatened by pollution and new dams affecting the flow of the river.
The problems have led to the creatures being upgraded from "endangered" to "critically endangered" by the World Conservation Union.