On the myology of the cephalic region and pectoral girdle of three ariid species, Arius heudeloti, Genidens genidens and Bagre marinus, and comparison with other catfishes (Teleostei: Siluriformes)

The muscles of the cephalic region and pectoral girdle of Arius heudeloti, Genidens genidens andBagre marinus are described and compared with those of non-ariid siluriforms. Our observations and compar-isons revealed that, although the configuration of the cephalic and pectoral girdle musculature of these ariidspecies is basically similar to that of other catfishes, these species present two myological peculiarities thatcould eventually represent autapomorphic characters of the family Ariidae, namely: 1) the muscle adductorarcus palatini inserts not only on the mesial margin of the suspensorium, but also on a significant part of thelateral surface of this complex structure; 2) the adductor mandibulae Aw is obliquely oriented, with its postero-dorsal fibres being significantly dorsal to the upper edge of the coronoid process.