Osteology and Myology of the Cephalic Region and Pectoral Girdle of Pangasius macronema, With a Discussion on the Synapomorphies and Phylogenetic Relationships of the Pangasiidae (Teleostei: Siluriformes)

The Siluriformes, with over 2750 species, constitute one of the most diverse Vertebrate taxa and are one of the economically important groups of fresh and brackish water fishes in the world (Teugels, 2003). Among the 35 siluriform families (Ferraris & De Pinna, 1999), the Asian family Pangasiidae includes several species of great economic importance in fisheries and fishculture (Teugels). Roberts & Vidthayanon (1991) recognised two pangasiid genera, with 21 species. However, recent taxonomic revisions have led to the description of numerous new pangasiid species (e.g. Pouyaud et al., 1999, 2000; Pouyaud & Teugels, 2000; Ng & Kottelat, 2000; Gustiano et al., 2003). In the most recent overview of siluriform systematics, Teugels recognised two pangasiid genera, Helicophagus and Pangasius, with 3 and 25 species, respectively.