It inhabits the river Paraguay, Average and Inferior Uruguay. Parana Average and Inferior and River de la Plata.It prefers the fangosos bottoms, with vegetation, to open and correntosas waters .
It is of a plomizo silver-plated color with five longitudinal strips, one throughout the back, whose dye it includes the color of the head, the ridge and the fatty one, a lateral strip of each side on the line of pores and narrower other underneath this line.
The head is great and proportionally low. The back of the head displays a bony granular knot. Long chins maxilares, until the origin of the volume or the end of the fatty one. The mentonianas arrive at pectoral and the postmentonianas to the aim of the same fins. Wide mouth. With the dorsal fin, high and in the pectoral thorns of a length smaller than the head. Denticulada in its two edges. Fatty: it releases. Volume: of unequal lobes, the prolonged number more exceeds the ventral in a quarter of its length.
Their dimensions rare time exceed the 60 both com and kg of weight.
It is identified it like a heavy inhabitant of the fluvial bottoms of resentment very decided. After that promissory beginning the fight is limited some lateral bullfights. When it is near the surface it is given and it reduced only "to tow it" with the own precautions of the diameter of used nylon and the obstacles that the river presents..