Identification key to Parauchenoglanis species 1a. Humeral process broadly triangular............................................................................................................................................................2 1b. Humeral process pointed........................................................................................................................................................................... 11 2a. Humeral process embedded under the skin; anterior margin of the pectoral-fin spine mostly serrated..................... P. zebratus 2b. Humeral process clearly visible through the skin; anterior margin of the pectoral-fin spine mostly smooth .............................3 3a. Rounded caudal fin (Fig. 4A).......................................................................................................................................................................4 3b. Truncated caudal fin (Fig. 4B) .....................................................................................................................................................................7 4a. Long barbels, external mandibular barbel reaching beyond distal tip of pectoral spine; total vertebrae count 50.0 mm SL) with numerous spots, with some of them forming five to seven (median six) vertical rows and with other black spots situated in between those rows (Fig. 5)............................................................................................................ P. ngamensis 5b. Head and fins with few black spots or spots entirely absent at all sizes (32.1–223.0 mm SL); body of medium- to large-sized specimens (> 100 mm SL) with black spots forming only five to six (median six, rarely seven) vertical rows and with no other spots situated in between these rows..........................................................................................................................................................6 6a. Head moderately depressed (head depth 48.5%–54.0% HL); deeper body depth, 15.5%–21.4% SL (Fig. 11) ......................... ........................................................................................................................................................................................................ P. patersoni 6b. Head highly depressed (head depth 34.6%–40.0% HL); shallower body depth, 11.6%–14.0% SL (Fig. 8) ................................ ................................................................................................................................................................................................ P. dolichorhinus 7a. Snout round or partly round; body with vertical rows of black blotches; head with black blotches.............................................8 7b. Snout bluntly triangular; body with black spots; head sometimes also with black spots................................................................9 8a. Vertical rows of black blotches extending onto adipose fin; blotches along the lateral line smaller than the eye size; eyes situated dorsally, i.e. high on the head, towards its upper surface (Fig. 12) ..................................................................... P. ernstswartzi 8b. Vertical rows of black blotches not extending onto adipose fin; blotches along the lateral line larger than the eye size; eyes clearly situated dorsolaterally (Fig. 13).............................................................................................................................. P. megalasma 9a. Head and fins with black spots; black spots present in between vertical rows of spots; external mandibular barbel not reaching the distal tip of pectoral-fin spine, when adpressed along the body ................................................................................. 10 9b. Head and fins without black spots or with faint black spots only; absence of black spots in between vertical rows of spots; external mandibular barbel reaching the distal tip of pectoral-fin spine, when adpressed along the body ............................... 11 10a. Mandibular barbels unspotted; only one or two black spots in between vertical rows of black spots; long predorsal length, 39.4%–42.0% SL (Fig. 10)........................................................................................................................................................ P. lueleensis 10b. Mandibular barbels spotted; more than two black spots in between vertical rows of black spots; short predorsal length, 38.4%–39.2% SL (Fig. 11)........................................................................................................................................................... P. poikilos 11a. Fins unspotted; high adipose fin height (Fig. 14)............................................................................................................ P. luendaensis 11b. Fins with faint black spots; low adipose fin height (Fig. 15) ...................................................................................... P. chiumbeensis 12a. Anterior margin of the pectoral-fin spine completely serrated........................................................................................................... 13 12b. Anterior margin of the pectoral-fin spine only partly and slightly serrated, or smoothly serrated ............................................. 15 13a. Caudal peduncle relatively long as high ............................................................................................................................... P. buettikoferi 13b. Caudal peduncle shorter than high.......................................................................................................................................................... 14 14a. Barbels long, with external mandibular barbel reaching beyond distal tip of pectoral-fin spine; colour pattern with 6–10 (rarely 11) vertical rows of spots .............................................................................................................................................. P. punctatus 14b. Barbels short, with external mandibular barbel not reaching beyond distal tip of pectoral spine; colour pattern with five to seven bands....................................................................................................................................................................................... P. monkei 15a. Preorbital head length greater than maximum head depth (measured at level of supraoccipital process); numerous small black spots on both head and fins............................................................................................................................................................. 16 15b. Preorbital head length less than maximum head depth; colour pattern of body and fins variable, but not as above.............. 17 16a. Interorbital distance 28%–30% HL; spots on head and flanks of equal size ..................................................................... P. longiceps 16b. Interorbital distance 22%–25% HL; spots on head smaller than those on flanks...................................................... P. pantherinus 17a. Adipose and dorsal fins high (adipose fin height, 5%–8% SL; dorsal fin height, 19%–30% SL); colour pattern on flank faint, one horizontal row of two to six large spots, being as large as or larger than the eye diameter, visible on the level of lateral line .......................................................................................................................................................................................................... P. altipinnis 17b. Adipose and dorsal fins shallower (adipose fin height, 3%–7% SL; dorsal fin height, 15%–25% SL); colour pattern of body and fins variable but not as above............................................................................................................................................................. 18 19a. Barbels long, with external mandibular barbel reaching distal tip of pectoral spine (minimum one-third HL); whole body covered with spots of equal size.......................................................................................................................................................... P.ahli 19b. Barbels short, with external mandibular barbel never reaching beyond distal tip of pectoral spine (shorter than one-third HL); whole body covered with spots of different sizes, arranged in horizontal and/or vertical rows............................. P. balayi

Published as part of Sithole, Yonela, Vreven, Emmanuel J. W. M. N., Bragança, Pedro H. N., Musschoot, Tobias & Chakona, Albert, 2024, Nine in one: integrative taxonomic evidence of hidden species diversity in the widespread Zambezi grunter, Parauchenoglanis ngamensis (Siluriformes: Auchenoglanididae), from southern and south-central Africa, pp. 1-33 in Zoological Journal of the Linnean Society 202 (3) on pages 28-29, DOI: 10.1093/zoolinnean/zlae121, http://zenodo.org/record/14504088