Author: Hoedeman, 1961
Comments: Appears to be smaller than <i>P. cristata</i>.  <i>P. geryi</i> and <i>P. cristata</i> share the same biotope.  Inhabits the high and middle parts of rivers, in zones with more or less fast flowing water and a rocky substrate (rock clusters consisting of pre-Cambrian pebbles, shales).  Lies hidden under rocks, letting its barbel out to auscultate the exterior world.  Emits growling sounds regularly (alarm signals?) and goes stalk-hunting frequently scouting around its hiding place.  The population is organized in a hierarchical structure based on size, with markedly aggressive behavior.  The juveniles are found mostly in seasonal little tributaries.  Diet changes according to size:  small crustaceans, insect larvae and adult, and fish.  This slow-growing species can live for more than 10 years in the wild (Ref. 35381).