This species is distinct from all its congeners by its possession of multicuspid jaw teeth and with the exception of P. nigrolineata, in having fewer vertebrae (39 vs. 40-55). Further, the following morphometric values are useful to distinguish this species from P. anisura and

P. provenzanoi, respectively: greater body depth 12.5-14.2% of SL (vs. 10.3-11.7% and 5.9-11.8%); greater cleithral width 15.1-16.5% of SL (vs. 13.6-14.5% and 10.2-13%); shorter adipose-fin base 16.1-18.2% of SL (vs. 19-20.3% and 19.4-23.8%); greater prepelvic length 41.9-43.3% of SL (vs. 37.6-40.4% and 33.5-40.8%); greater caudal peduncle depth 7.9-9% of SL (vs. 5.7-6.9% and 4.3-5.1%); greater head length 22.5-25.9% of SL (vs. 20.1-22.2% and 15.1-19%); longer maxillary barbel 30.6-39.4% of SL (vs. 26.2-28.3% and 21-27.8%); longer snout 38.5-43% of HL (vs. 34.9-37.8% and 31.4-36.8%) (Ref. 78618).