Parauchenoglanis patersoni, Sithole & Vreven & Bragança Tobias Musschoot & Chakona, 2024

Sithole, Yonela, Vreven, Emmanuel J. W. M. N., Bragança Tobias Musschoot, Pedro H. N. & 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, Zoological Journal of the Linnean Society 202, pp. 1-33 : 18-20

Parauchenoglanis patersoni sp. nov.

( Fig. 7; Table 3)

Common English name: Paterson’s grunter.

Common French name: Mâchoiron de Paterson.

Holotope: SAIAB 84804, 192.9 mm SL, Angola, Kwanza Basin , Posto 5 (9°48 ʹ 23″S, 15°24 ʹ 30″E); DNA sample ES07F293: SB9098; collector Ernst Swartz, 24 October 2007 .

Paratopes (N = 14): Angola: RMCA _ Vert _P.0001 (ex SAIAB 235741 ), one, 215.0 mm SL, collection details same as for the holotype; Kwanza, Posto 5 (9°48 ʹ 23″S, 15°24 ʹ 30″E); DNA sample ES07F295: SB9089; collector Ernst Swartz, 24 October 2007 . SAIAB 235741 (ex SAIAB 84804 ), two, 185.1–206.0 mm SL, collection details same as for the holotype; Kwanza, Posto 5 (9°48 ʹ 23″S, 15°24 ʹ 30″E); collector Ernst Swartz, 24 October 2007 . SAIAB 84844 , one, 223.0 mm SL, Kwanza River, Second Fishing village (9°46 ʹ 21″S, 15°32 ʹ 31″E), DNA sample ES07F374: SB9091; collector Ernst Swartz; 15 September 2009 . SAIAB 85190 , one, 117.0 mm SL, Kwanza Basin, Luando River, Bridge between Cimanga and Capunda (10°38 ʹ 26″S, 17°25 ʹ 06″E); DNA sample ES08B308 : SAFW563-09 ; collector Ernst Swartz; 18 September 2009 . SAIAB 235747 (ex SAIAB 84804 ), two, 52.7−65.6 mm SL, collection details same as for the holotype ; SAIAB 235746 (ex SAIAB 85190 ), five, 42.9–116.1 mm SL, Kwanza Basin, Luando River, Bridge between Cimanga and Capunda (10°38 ʹ 26″S, 17°25 ʹ 06″E); DNA sample ES08B310 : SAFW565-09 ; collector Ernst Swartz; 18 September 2009 . SAIAB 84625 , one, 88.8 mm SL, Kwanza Basin, Terra Nova village above bridge at Cambambe inflow (9°46 ʹ 44.0″S, 14°31 ʹ 24.0″E); DNA sample ESO7F041 : SAFW237-08 ; collector Ernst Swartz; 10 October 2007 . SAIAB 85520 , one, 59.5 mm SL, Kwanza Basin, Posto 5 (9°48 ʹ 23.0″S, 15°24 ʹ 30.0″E); DNA sample: ES07D096: SB9097; collectors Ernst Swartz, D. Neto and Paul Skelton; 19 August 2007 .

Diagnosis: Parauchenoglanis patersoni is distinguished from P. ahli , P. altipinnis , P. balaoi , P. buetikoferi , P. longiceps , P. monkei , P. pantherinus , and P. punctatus by a broad humeral process (vs. pointed humeral process). It is further distinguished from P. altipinnis , P. balaoi , P. pantherinus , and P. punctatus by a coarse skin (vs. smooth skin). It is differentiated from P. buetikoferi and P. monkei by anterior margin of the pectoral-fin spine mostly smooth (vs. anterior margin of pectoral-fin spine serrated from base to tip). Parauchenoglanis patersoni is distinguished from P. zebratus by a humeral process clearly visible through the skin, presence of five to six bars on small specimens or vertical rows of spots on large specimens (rarely seven), and anterior margin of the pectoral-fin spine mostly smooth (vs. humeral process embedded under the skin, four to five vertical rows of spots on small or four to five bars on large specimens, and anterior margin of the pectoral-fin spine mostly serrated). Parauchenoglanis patersoni is distinguished from P. stiassnoae by external mandibular barbel not reaching the tip of pectoral-fin spine (vs.reaching beyond the tip of pectoral-fin spine) and eyes positioned dorsolaterally (vs. dorsal). Parauchenoglanis patersoni is distinguished from P. ngamensis , P. lueleensis , P. poikilos , P. ernstswartzi , and P. megalasma by absence of black background spots in between the vertical bars or rows of spots [ Fig. 11A; vs. background spots present in P. ngamensis ( Fig. 5A), P. lueleensis ( Fig. 10A), and P. poikilos ( Fig. 11A) or vermiculated paưern in P. ernstswartzi ( Fig. 12A), or blotches in P. megalasma ( Fig. 13B)]. It is further distinguished from these five species by absence or presence of only few spots on the head and fins (vs. heavily spoưed in the other species). Furthermore, Parauchenoglanis patersoni is distinguished from P. dolichorhinus by a moderately depressed head, head depth 48.5%–54.9% HL (vs. depressed head, head depth 34.6%–40.0% HL); a deep body, 15.5%–21.4% SL (vs. shallower, 11.6%–14.0% SL), and posterior edge of anal fin reaching the posterior base of adipose fin (vs. not reaching posterior base of adipose fin). Parauchenoglanis patersoni is distinguished from P. chiumbeensis by posterior edge of anal fin reaching the posterior base of adipose fin (vs. reaching beyond level of posterior base of adipose fin) and external mandibular barbel not reaching tip of pectoral-fin spine (vs. reaching tip of pectoral-fin spine). Parauchenoglanis patersoni is distinguished from P. luendaensis by external mandibular barbel not reaching the tip of pectoral-fin spine (vs. reaching distal tip of pectoral-fin spine) and rounded caudal fin (vs. truncate).

Description: Morphometric and meristic data are given in Table 3. Body elongated. Dorsal body profile gently rising from snout tip to origin of dorsal fin, slightly concave from dorsal to adipose fin, and straight from adipose-fin origin to caudal-fin base. Body depth highest at origin of dorsal fin. Ventral body profile slightly convex from pectoral-fin origin to pelvic-fin origin and straight from pelvic-fin origin to caudal-fin base. Caudal peduncle laterally compressed. Anus and urogenital opening positioned about halfway between pelvic- and anal-fin origins. Adipose fin longer than anal-fin base, originating anteriorly to anal-fin origin, between pelvic-fin base and anal-fin origin, ending posteriorly to end of anal-fin base. Dorsal and pectoral fins with strong spine. Dorsal-fin origin anterior to pelvic-fin origin. Posterior edge of pectoral-fin ray does not reach pelvic fin. Anterior margin serrated on the distal end, and entire posterior margin of the pectoral-fin spine serrated. Caudal fin rounded.

Head moderately depressed. Snout profile bluntly triangular, on dorsal view ( Fig. 11B). Mouth subterminal. Lips fleshy. Eyes small and situated dorsolaterally. Ŋree pairs of barbels, base thick and tips pointed. External mandibular barbel longest, almost reaching the tip of the pectoral-fin spine. Inner mandibular barbel shortest, reaching middle of eye. Maxillary barbel reaching posterior edge of the eye, sometimes reaching slightly beyond posterior edge of the eye. Posterior nostril slits positioned about halfway between snout tip and eye.

Colouration in life: Overall body colouration varies from yellow dorsally to orange laterally. Mouth and distal tip of barbels and fins reddish (Supporting Information, Fig. S2). Arrangement of spots is discussed below.

Colouration in alcohol: Body light brown to grey dorsally and laterally, and light brownish to white ventrally. Body with five to six bars in small- and medium-sized specimens (42.9–62.6 mm SL). Large-sized specimens (116.1–223.0 mm SL) with black spots smaller than the eye forming five to six (seven in one specimen) vertical rows. Additional black spots between bars or vertical rows generally absent, but a few scaưered inconspicuous black spots might be present between the bars or vertical rows in both medium- and large-sized specimens. Head light brown. Fins with a few black spots, sometimes unspoưed. Distal tip of dorsal fin rays with a narrow black margin. Usually, one or two small black spots present above gill opening and one spot on midline of caudal-fin base. Barbels unspoưed.

Distribution: Parauchenoglanis patersoni is currently known from the mainstream of the Kwanza Basin ( Angola) above and below the Quissaquina Falls ( Fig. 1). Ŋis species co-occurs in this river section with the other Kwanza endemic species, P. dolichorhinus .

Etomologo: Ŋe species is named asser Dr Angus Paterson, the former managing director of the National Research Foundation– South African Institute for Aquatic Biodiversity (NRF-SAIAB), in appreciation and recognition of his determination and efforts to build taxonomic expertise and drive ichthyological exploration in poorly surveyed areas in southern Africa.