Gladioglanis conquistador N. Sp. from Ecuador with Diagnoses of the Subfamilies Rhamdiinae Bleeker and Pseudopimelodinae N. Subf. (Siluriformes: Pimelodidae)

Abstract

reduced vomer, low number of pectoral-fin rays, ornate pectoral spines, elongate coracoid keel, short but stout dorsal-fin spine, and dorso-ventral asymmetry of caudal-fin ray numbers. Gladioglanis conquistador n. sp., from the Rio Napo basin of Ecuador, is distinguished from its only congener, G. machadoi, by phylogenetically derived features (shorter dorsal-fin spine, anteriormost dorsal-fin pterygiophore in contact with neural spine of vertebra seven, 48-51 vertebrae) and several primitive features. The Rhamdiinae Bleeker is diagnosed by derived conditions of the transverse processes of vertebra four; vertical lamina on the Weberian centra; levator operculi crest on the hyomandibular bone; and quadrate and mesethmoid bones. Tentative subgroups within the Rhamdiinae are suggested based on putative synapomorphies. The Pseudopimelodinae n. subf. is diagnosed by derived conditions of the lateral ethmoid wing; metapterygoid, endopterygoid, and ectopterygoid; proximal radials of the dorsal fin; and hypohyal bones. Within the Pseudopimelodinae, Zungaro is proposed as the sister group of Microglanis, Pseudopimelodus and Lophiosilurus. Derived conditions of oral lip folds and sulci are surveyed across the Siluriformes and it is concluded that, taken alone, the similarity of derived lip structures shared by the Rhamdiinae and most members of Pseudopimelodinae provides only weak evidence for a sister-group relationship between them.