From Dierickx et al. (2024).
Distinguished from its congeners by the following unique combination of characters: a slender tail (15.3%–19.2% BD vs. thicker, 21.7%–31.2% BD, in P. brevis, P. castelnaui, P. fasciaticeps, P. guttatus, P. isidori, P. krameri, P. marianne, P. nigricans, P. petricolus, P. stappersii, P. vanneeri, and P. weyli); a blocky snout (vs. rounded snout in P. brevis, P. castelnaui, P. guttatus, P. krameri, P. marianne, P. petricolus, P. stappersii, P. vanneeri, and P. weyli); pointed pectoral fin (vs. rounded in P. brevis, P. castelnaui, P. guttatus, P. krameri, P. marianne, P. petricolus, P. stappersii, P. tumifrons, P. vanneeri, and P. weyli); concave anal and dorsal fins (vs. rounded in P. brevis, P. castelnaui, P. guttatus, P. krameri, P. marianne, P. petricolus, P. stappersii, P. vanneeri, and P. weyli); absence of chin (vs. obvious chin in P. brevis, P. castelnaui, P. guttatus, P. krameri, P. marianne, P. petricolus, P. stappersii, P. vanneeri, and P. weyli); small, widely spaced, symmetrical teeth with clear cusps; a short head (20.9%–22.8% SL vs. 23.2%–27.7% SL in P. adspersus, P. maculipinnis, P. osborni, and P. pulverulentus); a short dorsal fin (20.4%–23.9% SL vs. shorter, 15.2%–19.5% SL, in P. maculipinnis and P. schreyeni, and longer, 25.0%–37.9% SL, in P. pedunculatus and C. plagiostoma); and anterior nostril positioned higher than the posterior one (vs. vice versa in P. pedunculatus).