It is an endemic species of South America . Also call "chucho of river" is one of the fish greater than they are in the Paranaense river basin. Some units can surpass the 100 kg is feared for the possession of a prong in their fin of great volume, used to defend and that it causes very strong pains in the wound. Often this is undergone by fishermen or occasional swimmers who step on or touch a ray and cause the immediate reaction of this one.

It is a fish very flattened back-ventral, with oval disc form more or less extended, with the tail a little shorter than the length of the body. This one is brown dark with yellow ocelos of I haul black, distributed by he himself and more or less distanced to each other.

Is it in Medium and Inferior the Parana river; in the Corrientes river and the matting of the Iberá. Average the Uruguay river; river Plate and in several rivers of Brazil . It is of viviparous reproduction and its nourishing regime is carnivorous.

In spite of attractive of his size, fishing it offers some difficulties, since once taken the hook, if the ray is great is little than less impossible to recover the fish, that adheres to the bottom and most of the times it is necessary to cut the line. On the other hand the fishermen fear of their prong and they are not loving of its meat. The fishing specially in summer with line of bottom and natural bait.