Osteology and myology of the cephalic region and pectoral girdle of Schilbe mystus and comparison with other schilbids, with comments on the monophyly and phylogenetic relationships of the Schilbidae (Teleostei: Siluriformes)

The cephalic and pectoral girdle structures of Schilbe mystus are described and compared with those of other schilbids, as well as several other non-schilbid catfishes, as the foundation for a discussion on the monophyly and the phylogenetic relationships of the Schilbidae. Our observations and comparisons suggest that the family Schilbidae is a monophyletic group, defined, at least, by three autapomorphies, namely: 1) the adductor mandibulae A2 is lateral to the A1-Ost; 2) the posterior margin of the horizontal portion of Meckel's cartilage is situated further beyond the coronoid process; 3) the adductor mandibulae A is visible in a lateral view of the cephalic region. With respect to the phylogenetic relationships of the Schilbidae, our observations and comparisons support a close relationship between this family and the Pangasiidae.