Pareiorhaphis garapia can be distinguished from all congeners by having the following characters: nuchal plate covered by thick skin and not exposed (vs. nuchal plate exposed and supporting odontodes); posterior process of the cleithrum narrow and elongate (vs. process wide, roughly rectangular); and last segment of the preopercular ramus of the latero-sensory canal limited to an ossified tubule or with a very narrow laminar expansion, always narrower than the canal itself (vs. canal associated to a wide laminar expansion, always wider than the canal). It further differs from most species except P. mutuca, P. vestigipinnis, P. calmoni, P. nudulus, P. hypselurus, P. stomias and P. lophia by the absence of the dorsal-fin spinelet. It can be distinguished from species without a spinelet, except P. nudulus and P. calmoni, by the narrower body at anal-fin origin (9.9-12.0 vs. 12.2-18.3% SL). The pectoral-fin spine in adult males is short and slightly curved, maximally reaching to the origin of the pelvic fin when adpressed (vs. pectoral-fin spine long, straight and reaching to one half of the pelvic-fin length, further distinguish the new species from P. nudulus and P. calmoni). In addition, it differs from all congeners, except P. nudulus, by having reduced number of plates on the snout, predorsal area and in the dorsal and mid-dorsal series, forming a large gap devoid of dermal plates between the dorsal and the adipose fins of apparently sexually mature but not fully developed individuals, measuring up to 50 mm SL (Ref. 105131).