Total gill rakers 11-14 on last arch. Eye diameter 8.9-15.3% HL. Because of its similarity to A. midgleyi, the remaining diagnosis refers to both A. midgleyi and A. paucus: a sleek body; strong jaws; jaws upturned slightly at symphyses, mouth broad; snout truncate in profile; head oblong, its width averaging 66% HL. Supraoccipital process narrow with parallel margins. Numerous fine, sharp teeth on palate in transverse band of four oblong groups. No rakers on posterior aspect of gill arches. Barbels thin and short, rarely reaching beyond pectoral fin base and less than 25% SL (Ref. 40908).