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)

Sep 1, 2007

The cephalic and pectoral girdle structures of Pangasius macronema are described and compared with those of another representative of the same genus, Pangasius larnaudii, and of representatives of the other pangasiid genus, Helicophagus leptorhynchus and Helicophagus typus, as well as of several other catfishes, as the foundation for a discussion of the synapomorphies and phylogenetic relationships of the Pangasiidae. The following two features could constitute Pangasiidae autapomorphies: 1) presence of prominent crest on the dorso-lateral surfaces of both the hyomandibulo-metapterygoid and the ento-ectopterygoid; 2) presence of a large, circular foramen between the anterodorsomedial surface of the extrascapular, the dorsomesial surface of the pterotic and the dorsolateral surface of the parieto-supraoccipital. With respect to the phylogenetic relationships of the Pangasiidae, this family is seemingly closely related to the Schilbidae.