The armed ones are contained in a typical family of South America ; some of their species reach good size.

They are siluriformes and they are characterized to present a row of bony plates throughout his flanks, the head generally very osificada and three pairs of chins.

The dorsal fin and the pectoral ones have a osificado radius strongly, sawed generally. In the country there are three species, the armed pig or target (Oxydora kneri), armed common (Pterodoras granulosus) and the yellow armed one (Rhinodoras dorbignyi). All of them very appreciated, because they show high signs of voracity. Between armed, the favorite as fishing object is the armed pig, because he is the one that reaches greater size. It gets to measure 70 centimeters in length and grief up to nine kilos. Omnívoro is a fish, that is fed on insects, moluscos, crustaceans, rest of animals and vegetables.
Its snout is prolonged and finishes in characteristic heavy lips, with short chins. It lives in Inferior Parana during the autumn and, in spring, is specially it in the superior course of this river. Its reproduction takes place in summer. The common armed one appears in all the river basin of the Silver; one registers his presence between October and March.
The yellow armed one is also a fish of considerable size, since it gets to measure means meter. Other species, however, of are reduced to dimensions, as the small one armed (Dora eigenmanni) that are in Formosa and whose speckled body does not surpass the ten centimeters in length. Another representative of the group is the call vulgarly yararira (Platydoras costatus).