Most aquarium catfishes come from South America, they are widespread there. People find the locations that are known to catfish families in the northern countries, Colombia and Venezuela. In the southern countries. people only think of Corydoras undulatus from Argentina. On this continent the climatic conditions vary considerably. Countries like Uruguay and Argentina show a subtropical climate. Paraguay is open in contrast to a small stretch of coast on the east and Southern Brazil still has oceanic tropical climate counts. The climate of Southern Brazil is a transitional climate from the tropics to the milder subtropics. This, therefore indicates that tank catfishes don't have always to be kept in a stable environment.