This species is distinguished from its congeners: except P. azygolechis, in having the lower lip margin densely fringed (vs. smooth or just slightly fringed); except with P. garbei and P. azygolechis in having a series of 6-10 (usually 7-9) small median, preadipose azygous plates, forming a low postdorsal ridge between the dorsal and the adipose fins (vs. none to 5 preadipose plates); from all remaining species except P. calmoni, P. bahianus, P. nudulus, P. hypselurus, and P. stomias by the pectoral-fin spine very long and straight, reaching the distal third of the pelvic fin when adpressed in adult males (vs. spine short and curved and maximally reaching half of the pelvic-fin length); differs from most species, except P. eurycephalus, P. hypselurus, P. stomias, and P. stephanus by having the hypural

plate asymmetrical with the lower lobe longer than the upper (vs. hypural plate approximately symmetrical) (Ref. 91743).