slight notch with corresponding emargination in upper jaw. Two pairs of barbels (often missing on either side):
rostral and maxillary barbels generally short and tiny, often rudimentary, with rostral barbel length generally far
shorter than 50% of distance between origin of rostral barbel and corner of mouth. Rostral barbel often under
rostral groove. Eye large but size generally decreases with body length, from diameter longer than snout in small
specimens to slightly shorter than snout in large specimens. Infraorbital bones large. Presumed fully developed
male with greatly enlarged chest (Figs. 1B and E).