[Pavel Chaloupka]

I of course know very little about paro habitats, but from what I know about some South American species, quite a lot of them are not found in strictly one type of water as far as color goes as long as other parameters like hardness and acidity are met. Some Nannostomus and Rivulus occur in both blackwater and clearwater. + the color of the water may change over years. So if Bernd cought them in clearwater, it does not have to mean they occur strictly in clearwater habitats and vice versa. The coloration they have may be useful even in clearwater environment with dense growth of costal vegetation over the water surface as there is also very little light penetrating.