Osteology and myology of the cephalic region and pectoral girdle of Batrochoglanis raninus, with a discussion on the synapomorphies and phylogenetic relationships of the Pseudopimelodinae and Pimelodidae (Teleostei: Siluriformes)

The cephalic and pectoral girdle structures of the pseudopimelodin Batrochoglanis raninus are described and compared to those of a representative of another pseudopimelodin genera, namely Microglanis cottoides, as well as to several other pimelodid and non-pimelodid catfishes, as the foundation for a discussion on the synapomorphies and phylogenetic relationships of the Pseudopimelodinae. Our observations and comparisons pointed out two new, additional features that could represent potential Pseudopimelodinae synapomorphies: 1) mesethmoid markedly bifurcated anteriorly; 2) spoon-shaped autopalatine with a somewhat roundish, markedly enlarged dorsoventrally, posterior tip. In addition, our observations and comparisons indicate that the subfamilies Pseudopimelodinae, Pimelodinae and Heptapterinae do constitute a monophyletic assemblage, and, thus, contradict the commonly accepted idea that the family Pimelodidae is a polyphyletic group.