Species that is frequently in the smaller courses. The Maxima age registered has been of 6 years.

It is a migratory species. The greater individuals of 30 cm above move waters from Santa Fe until Incarnation (Paraguay). Also one is distributed in the river basins of the Pilcomayo river in Formosa, of Bermejo in It jumps and Salí in Tucumán, and the rivers Paraguay, Average and Inferior, Sweet Parana, Oath, Average and Inferior Uruguay, and of the Silver.

It presents a defensive system conformed by the three first radii of the fins dorsal and pectoral, rigid and indented backwards, of extreme sharpness in the ends and covered by an anticoagulating substance and of very painful action in weaves.

This species has two present phases of color in different individuals and that sometimes he himself unit adopts, that can acquire stained" or "overo" the one of "in the aquarium. The yellow catfish is of ocráceo yellow color, almost white in the belly. The ""stained" overo" or displays great ready spots of brown color in longitudinal rows. In each flank there are five rows and its size is more or less like the eye.

The head is great and high. The back of the head is covered by a fine skin and the chins maxilares arrive at the fatty one; the mentonianas to the 3/4 of the head and postmentonianas in the middle of the pectoral fins. Mouth is wide with salient superior lip.

All the fins have small specks, except for the fatty ones, that have greater spots like those of the body. The dorsal fin is high; its thorn indented in the later face in all its length is minor who the head. The pectoral fin is indented in both faces. The fin of great volume has almost equal lobes, being superior the slightly greater one.

It does not reach great bearings; common pieces of around 40 cm and a weight are registered that does not arrive at 1 kg.