Panaqolus claustellifer is distinguished from most of its congeners by its color pattern of dark and light bars on the body, bands on the fins, and with dots and vermiculations absent (vs. no bars in P. albomaculatus, P. nix, P. nocturnus, and P. koko; vs. fins unbanded in P. albomaculatus, P. dentex, P. koko, and P. nix; and vs. dots and vermiculations present in P. albivermis and P. maccus). It also differs from P. albivermis, P. albomaculatus, and P. nix by dentaries forming an acute angle ~70º (vs. dentaries forming a very acute angle to dentaries parallel), and from P. koko by spoon-shaped teeth with small lateral cusps (vs. quadrate teeth with strong lateral cusps). It can be differentiated from other barred species of Panaqolus by the specific bar number and orientation and color pattern on the head, with bars oriented in a anteroventral-posterodorsal direction (vs. anterodorsal-posteroventral bars in P. gnomus), having consistently 5 bars (n = 4) on the trunk that do not increase with size (vs. number increasing with size in P. purusiensis and fading at body sizes >85 mm SL, and vs. 6-12 in P. changae), and the color pattern on the head of straight lines extending from posterior to the eye to the snout margin, splitting in the middle portion of the line in larger specimens (vs. small, dense reticulate lines in P. changae) (Ref. 109759).