Author: (Valenciennes, 1840)
Remark: Redescription in Armbruster & Hardman (1999); ecology in Serpa (1967). Biology: in large rivers, backwaters and floodplain lakes.
Comments: Found in small sluggish streams, floodplain lakes and large rivers generally in very soft water (Ref. 89711). Water quality measurements from Ushpa Caño showed that the water was very low in oxygen, but neutral (pH 7.0). Was observed to breathe air and when disturbed, would swim through the water column remaining neutrally buoyant.  The species is not an obligate air-breather and does not routinely gulp air in well-oxygenated aquaria. Minimum temperature from Ref.13614.