Auchenoglanis occidentalis (Valenciennes, 1840)

Geerinckx, Tom & Vreven, Emmanuel, 2013, A re-evaluation of the species-level diversity within the catfish genus Auchenoglanis (Siluriformes: Claroteidae), Journal of Natural History 47 (47 - 48), pp. 2979-3010 : 3002-3007

Auchenoglanis occidentalis (Valenciennes, 1840)

( Figure 8B )

Pimelodus occidentalis Valenciennes 1840 (in Cuvier & Valenciennes, 1840)

Oxyglanis sacchii Vinciguerra 1898

Auchenoglanis occidentalis var. tanganicanus Boulenger 1906

Auchenoglanis occidentalis var. tchadiensis Pellegrin 1909

Auchenoglanis acuticeps Pappenheim 1914 (in Pappenheim & Boulenger 1914) Auchenoglanis wittei Giltay 1930

Material examined

Holotype. MNHN 8971 : Senegal River , Senegal; 358 mm SL.

Other material. Specimens are listed per river basin (from northwest to southeast).

Senegal basin . MRAC 73-5-P-2811: Djeuss River at Dakar Bango, Senegal basin, Senegal; 16 ◦ 03 ′ N, 16 ◦ 27 ′ W; 140 mm SL. MRAC 79-2-P-216: camp Djoudj, Gorom River, Senegal basin, Senegal; 16 ◦ 22 ′ N, 16 ◦ 16 ′ W; 143 mm SL.

Gambia basin . MRAC 79-2 -P-217: Ba-Foula-Bé , Gambia River, Senegal; 13 ◦ 02 ′ N, 13 ◦ 12 ′ W; 158 mm SL. MRAC 80-1 -P-100: same locality; 352 mm SL. MRAC 81-3 -P- 382: same locality; 420 mm SL. MRAC 89-1 -P-98: same locality; 140 mm SL .

Casamance basin . MRAC 73-5 -P-2815–2817: Casamance River at Kolda, Senegal; 12 ◦ 53 ′ N, 14 ◦ 56 ′ W; 3 spm, 154–272 mm SL .

Taia (Tai, Toja) basin . MRAC 73-10-P-3532: Njala, Taia River, Sierra Leone; 8 ◦ 07 ′ N, 12 ◦ 05 ′ W; 184 mm SL.

Moa basin . MRAC 73-10-P-3534: Pendehun, Moa River, Sierra Leone; 8 ◦ 13 ′ N, 11 ◦ 03 ′ W; 388 mm SL. MRAC 73-10-P-3536–3537: Pendehun, Moa River, Sierra Leone; 8 ◦ 13 ′ N, 11 ◦ 03 ′ W; 2 spm, 124–138 mm SL. MRAC 73-10-P-3533: marsh near Moa River, Sierra Leone; c.7 ◦ 53 ′ N, 11 ◦ 08 ′ W; 128 mm SL. MRAC 73-10-P-3539: tributary of Moa River at Majihun, Sierra Leone; 7 ◦ 51 ′ N, 11 ◦ 07 ′ W; 192 mm SL.

Sassandra basin . MRAC 85-29-P-500: Bac Sémien, Sassandra River, Ivory Coast; c.7 ◦ 43 ′ N, 7 ◦ 04 ′ W; 228 mm SL. MRAC 85-29-P-505: same locality; 149 mm SL.

Bandama basin . MRAC 86-36-P-89: Bandama River, Ivory Coast; 8 ◦ 46 ′ N, 5 ◦ 32 ′ W; 41 mm SL. MRAC 85-55-P-283: N’Zi River, Ivory Coast; 8 ◦ 16 ′ N, 4 ◦ 48 ′ W; 121 mm SL. MRAC 87-18-P-4673: Maraoué River, Ivory Coast; 8 ◦ 03 ′ N, 6 ◦ 34 ′ W; 85 mm SL.

Comoé basin . MRAC 85-55 -P-284–285 : Comoé River at Gansé, Ivory Coast; 8 ◦ 37 ′ N, 3 ◦ 55 ′ W; 145–174 mm SL .

Volta basin . MRAC 144217 : Black Volta River , Burkina Faso; 154 mm SL . MRAC 144218–219 : Massili River , Burkina Faso; c.12 ◦ 29 ′ N, 1 ◦ 24 ′ W; 2 spm, 101–139 mm SL . MRAC 144220 : Nagbagré dam (Boulbé River), Burkina Faso; 12 ◦ 12 ′ N, 1 ◦ 24 ′ W; 192 mm SL . MRAC 73-7 -P-348–349: Anpem , Lake Volta, Ghana; 2 spm, 122–130 mm SL . MRAC 93-28 -P-16: Yeji , Lake Volta, Ghana; 8 ◦ 13 ′ N, 0 ◦ 39 ′ W; 215 mm SL . MRAC 93-28 -P-15: Jaklai , near Yeji, Lake Volta, Ghana; 8 ◦ 12 ′ N, 0 ◦ 38 ′ W; 126 mm SL . MRAC 87-18 -P-4674: Pru River , Ghana; 7 ◦ 54 ′ N, 1 ◦ 10 ′ W; 138 mm SL . MRAC 73-13 -P-245–246: Borgou , Zan Sargou River, Togo; c.10 ◦ 46 ′ N, 0 ◦ 35 ′ E; 2 spm, 134–135 mm SL . MRAC 73-13 -P-247–248: Passere , Oti River, Togo; 2 spm, 214–217 mm SL .

Niger basin . MRAC 73271 : Bamako , Niger River, Mali; c.12 ◦ 38 ′ N, 7 ◦ 59 ′ W; 142 mm SL . MRAC 73-12 -P-369: Mopti Sud (amont grille), Niger River, Mali; 14 ◦ 30 ′ N, 4 ◦ 12 ′ W; 90 mm SL . MRAC 75-36 -P-115: Lake Kainji , Nigeria; c.10 ◦ 18 ′ N, 4 ◦ 33 ′ E; 37 mm SL . MRAC 92-78 -P-219: Lake Isemu , Nigeria; 5 ◦ 09 ′ N, 6 ◦ 24 ′ E; 78 mm SL . MRAC 93-63 -P-252: swampforest borrow pit, Nigeria; c.5 ◦ 08 ′ N, 6 ◦ 21 ′ E; 150 mm SL . MRAC 76-32 -P-954: South of Keffi , Nigeria; c.8 ◦ 47 ′ N, 7 ◦ 53 ′ E; 49 mm SL . MRAC 73-15 -P-1023: Garoua , Benoué River, Cameroon; 9 ◦ 18 ′ N, 13 ◦ 24 ′ E; 144 mm SL .

Orashi basin . MRAC 91-1 -P-229: Odieke , Orashi River, Nigeria; 5 ◦ 12 ′ N, 6 ◦ 40 ′ E; 153 mm SL .

Cross basin . MRAC 88-53-P-354: Cross River, Cameroon; 5 ◦ 48 ′ N, 9 ◦ 18 ′ E; 63 mm SL.

Lake Chad basin . MNHN 09–425 (lectotype and paralectotypes of A. occidentalis tchadiensis , examined on pictures): Lake Chad at Bol (N’Gui Boul du Sud), country uncertain; 3 spm, 46–59 mm SL. MNHN 09–426 (paralectotypes of A. occidentalis tchadiensis , examined on pictures): same locality; 4 spm, 38–49 mm SL. MRAC 154047: Bahr-Tinga River, Parc de Zakouma, Chad; c.10 ◦ 53 ′ N, 19 ◦ 45 ′ E; 216 mm SL. MRAC 19734: Gribingui River, Central African Republic; c.8 ◦ 29 ′ N, 19 ◦ 04 ′ E; 103 mm SL. MRAC 82-21-P-738–740: Gounda River, Central African Republic; 9 ◦ 02 ′ N, 21 ◦ 15 ′ E; 3 spm, 95–157 mm SL. MRAC 84-32-P-146: Lim River, Central African Republic; c.7 ◦ 20 ′ N, 15 ◦ 34 ′ E; 58 mm SL. MRAC 73-15-P-1021: Yagoua, Mayo Klera River, Cameroon; 10 ◦ 21 ′ N, 15 ◦ 17 ′ E; 127 mm SL. MRAC 73-15-P-1008: Guémé, Logone River, Cameroon; 10 ◦ 30 ′ N, 15 ◦ 11 ′ E; 92 mm SL. MRAC 73-16-P-5489: Yagoua, Logone River (bought), Cameroon; 10 ◦ 21 ′ N, 15 ◦ 17 ′ E; 215 mm SL.

Nile basin . MRAC 83-30 -P-95–96: Lake Nasser , Nile River, Egypt; c.22 ◦ 31 ′ N, 31 ◦ 46 ′ E; 2 spm, 349– 322 mm SL . MRAC 84-6 -P-112: same locality; 375 mm SL . ZMB 19094 (lectotype of A. acuticeps , examined on pictures): Lake Albert (country unknown); 168 mm SL . ZMB 21317 (paralectotypes of A. acuticeps , examined on pictures): same locality; 3 spm, 126–166 mm SL . MRAC 20871 : Kasenyi, Lake Albert, D.R. Congo; 1 ◦ 24 ′ N, 30 ◦ 27 ′ E; 251 mm SL . MRAC 44937 : same locality; 304 mm SL . ZMUC P28106 (examined on pictures): Amadi , Yei River, South Sudan; 188 mm SL .

Lake Turkana basin . MSNG 14.506 (holotype of Oxyglanis sachii , examined on pictures): Omo River at Murzu, Lake Turkana basin, Ethiopia; 330 mm SL .

Congo basin (excluding Lake Tanganyika ). MRAC 78128 : Kinshasa, Congo River, D.R . Congo; c.4 ◦ 18 ′ S, 15 ◦ 17 ′ E; 133 mm SL. MRAC A8-20 -P-987–989: Léfini River mouth, Congo Republic; 2 ◦ 56 ′ 52.89 ′′ S, 16 ◦ 10 ′ 6.62 ′′ E; 3 spm, 100–160 mm SL. MRAC 57745 : Lake Tumba , D.R . Congo; 0 ◦ 45 ′ S, 18 ◦ 01 ′ E; 225 mm SL. MRAC 100765–766 : Lake Tumba , D.R . Congo; 0 ◦ 45 ′ S, 18 ◦ 01 ′ E; 200–247 mm SL. MRAC 82-13 -P-1710: Landjia, Oubangui River, Central African Republic; 4 ◦ 22 ′ N, 18 ◦ 38 ′ E; 169 mm SL. MRAC 82-13 - P-1711: pond near Landjia , Central African Republic; 4 ◦ 22 ′ N, 18 ◦ 38 ′ E; 141 mm SL. MRAC 72573 : Flandria , Momboyo River, D.R. Congo; 0 ◦ 22 ′ 41.75 ′′ S, 19 ◦ 04 ′ 39.47 ′′ E; only head preserved, 221 mm HL. MRAC 73-23 -P- 5164: Boende, Tshuapa River, D.R. Congo; 0 ◦ 14 ′ S, 20 ◦ 50 ′ E; 235 mm SL. MRAC 84-32 -P-153: Kongbo, Bangui Kete River , Central African Republic; 5 ◦ 00 ′ N, 21 ◦ 17 ′ E; 236 mm SL. MRAC 84-32 -P-152: Ngouakoubo River, Central African Republic; c.5 ◦ 21 ′ N, 20 ◦ 39 ′ E; 99 mm SL. MRAC 58634 : Yakoma , Ubangui River, D.R. Congo; 4 ◦ 06 ′ 54.30 ′′ N, 22 ◦ 26 ′ 28.65 ′′ E; 287 mm SL. MRAC 82-21 -P-737: Liwa River, tributary of Ouaka River , Central African Republic; 69 mm SL. MRAC 84-32 -P-335: Oubangui River, Central African Republic; 210 mm SL. MRAC 88-25 - P-1656: Bumba, D.R. Congo; 2 ◦ 11 ′ N, 22 ◦ 32 ′ E; 91 mm SL. MRAC B0-21-P-815: Lomami River near Djabir, D.R. Congo; 0 ◦ 28 ′ 33.9 ′′ N, 24 ◦ 09 ′ 47.7 ′′ E; 80 mm SL. MRAC B0-21-P-818: Congo River near Batikamondji, D.R. Congo; 0 ◦ 08 ′ 19.6 ′′ N, 24 ◦ 31 ′ 12.4 ′′ E; 168 mm SL. MRAC 123541 : Yangambi , Isalowe River, D.R. Congo; 0 ◦ 46 ′ N, 24 ◦ 29 ′ E; 189 mm SL. MRAC 61597 : Buta , Rubi River, D.R. Congo; c.2 ◦ 47 ′ N, 24 ◦ 50 ′ E; 151 mm SL. MRAC 88-25 -P-1657: Tshopo River at Kisangani, D.R. Congo; 0 ◦ 32 ′ N, 25 ◦ 11 ′ E; 44 mm SL. MRAC 19802 (holotype of A. wittei ): Kisangani , Congo River, D.R. Congo; c.0 ◦ 30 ′ N, 25 ◦ 11 ′ E; 51 mm SL. MRAC 19803 (paratype of A. wittei ): same locality; 46 mm SL. MRAC 70094–095 : Kindu , Lualaba River, D.R. Congo; 2 ◦ 57 ′ S, 25 ◦ 56 ′ E; 2 spm, 146–154 mm SL. MRAC B0-21-P-821: Loboya River near Bambondji, D.R. Congo; 0 ◦ 11 ′ 33.6 ′′ N, 25 ◦ 31 ′ 51.1 ′′ E; 100 mm SL. MRAC 75191 : Maniema , Ulindi River, D.R. Congo; c.3 ◦ 04 ′ S, 26 ◦ 02 ′ E; 244 mm SL. MRAC 83159 : Kikondje (Kikondja) , Lualaba River close to channel of Lake Kisango-Lungwe , D.R. Congo; 8 ◦ 12 ′ S 26 ◦ 26 ′ E; 78 mm SL. MRAC 79-1 - P-4373–4375: Lake Upemba at Mabwe, D.R. Congo; 8 ◦ 39 ′ 2.27 ′′ S 26 ◦ 30 ′ 25.84 ′′ E; 3 spm, 212–260 mm SL. MRAC 69938 : Kabalo , swamp near Lualaba River, D.R. Congo; 6 ◦ 02 ′ 56.96 ′′ S, 26 ◦ 54 ′ 42.11 ′′ E; 105 mm SL. MRAC 72708 : Mulongo, Lake Kabamba , D.R. Congo; 7 ◦ 50 ′ 43.45 ′′ S, 27 ◦ 00 ′ 3.46 ′′ E; 3 spm, 198–236 mm SL. MRAC A6-44 - P-13: Mulongo, Lake Kabamba , D.R. Congo; 7 ◦ 50 ′ 43.45 ′′ S, 27 ◦ 00 ′ 3.46 ′′ E; 144 mm SL. MRAC 83165 : swamps near Manono (Lukushi River), D.R. Congo; 7 ◦ 18 ′ S 27 ◦ 27 ′ E; 272 mm SL. MRAC 94-19 -P-2133: Kashilu, Luapula River, Zambia; c.9 ◦ 27 ′ S 28 ◦ 31 ′ E; 108 mm SL. MRAC 72689 : N′ Kole, Luapula River, Zambia; 9 ◦ 26 ′ S 28 ◦ 32 ′ E; 301 mm SL. MRAC 99-67 - P- 416: Nchelenge, Lake Mweru , Zambia; c.9 ◦ 21 ′ S 28 ◦ 44 ′ E; 200 mm SL. MRAC 99-67 - P-422: Nchelenge, Lake Mweru , Zambia; c.9 ◦ 21 ′ S 28 ◦ 44 ′ E; 132 mm SL. MRAC 94-19 - P-986: Lake Mweru , Kalungwishi River mouth, Zambia; 9 ◦ 02 ′ 7.43 ′′ S, 28 ◦ 56 ′ 3.16 ′′ E; 91 mm SL .

Lake Tanganyika (Congo) basin . BMNH 1906.9.6.37–38 (lectotype and paralectotype of A. occidentalis tanganicanus , examined on pictures): Kalambo , Lake Tanganyika, Tanzania; 2 specimens, 284–296 mm SL . BMNH 1906.9 .6.39 (paralectotypes of A. occidentalis tanganicanus , examined on pictures): middle of Lake Tanganyika , Tanzania; 315 mm SL . MRAC 11630 : Lake Tanganyika , close to mouth of Petite Ruzizi River, D.R. Congo; 3 ◦ 21 ′ 12 ′′ S, 29 ◦ 12 ′ 31 ′′ E; 60 mm SL . MRAC 43821 : Usumbura , Lake Tanganyika, Burundi; 3 ◦ 23 ′ S 29 ◦ 21 ′ E; 250 mm SL . MRAC 90239–240 : Usumbura , Lake Tanganyika, Burundi; 3 ◦ 23 ′ S 29 ◦ 21 ′ E; 87–180 mm SL . MRAC 125771 : Uvira , Lake Tanganyika, D.R. Congo; 3 ◦ 25 ′ S 29 ◦ 09 ′ E; 193 mm SL . MRAC B0-12-P-74: Lake Tanganyika at Baraka, D.R. Congo; 4 ◦ 05 ′ 30.67 ′′ S, 29 ◦ 05 ′ 40.35 ′′ E; 256 mm SL . MRAC 63768 : Kalemie , Lake Tanganyika, D.R. Congo; 5 ◦ 56 ′ S 29 ◦ 12 ′ E; 328 mm SL . MRAC 90244 : Kalemie , Lake Tanganyika, D.R. Congo; 5 ◦ 56 ′ S 29 ◦ 12 ′ E; 184 mm SL . MRAC 92-81 -P-1887–1888: Kanyasa , Lake Tanganyika, Tanzania; c.5 ◦ 56 ′ S 29 ◦ 54 ′ E; 2 spm, 99–207 mm SL . MRAC B0-12-P- 73: Lake Tanganyika at Kalemie, D.R. Congo; 5 ◦ 56 ′ 1.18 ′′ S, 29 ◦ 11 ′ 53.62 ′′ E; 223 mm SL . MRAC B0-12-P-75: same locality; 98 mm SL . MRAC 90237 : Moba Bay , Lake Tanganyika, D.R. Congo; 7 ◦ 03 ′ S 29 ◦ 47 ′ E; 480 mm SL . MRAC 14348 : Vua Bay , Lake Tanganyika, D.R. Congo; c.8 ◦ 06 ′ S 30 ◦ 33 ′ E; 527 mm SL . BMNH 1906.9 .8.69 (paralectotype of A. occidentalis tanganicanus , examined on pictures): Mtondwe Bay (NE of Mpulungu), Lake Tanganyika, Zambia; c.8 ◦ 45 ′ S 31 ◦ 08 ′ E; 258 mm SL . MRAC 93-152 -P-371: Iragala (Ilagala), Malagarazi River, Tanzania; 5 ◦ 12 ′ 47.02 ′′ S, 29 ◦ 50 ′ 34.13 ′′ E; 106 mm SL . MRAC 90241 : Malagarazi River , Tanzania; 5 ◦ 13 ′ S 29 ◦ 51 ′ E; 58 mm SL .

Lake Rukwa basin . MRAC 94-34 -P-817: Kazizi, Lake Rukwa, Tanzania; c.7 ◦ 37 ′ S 31 ◦ 35 ′ E; 241 mm SL .

Diagnosis

Auchenoglanis occidentalis is distinguished from A. biscutatus by the horizontal distance between the eye and the end of the supraoccipital process being as long as, or shorter than, the horizontal distance between the snout tip and the eye ( Figure 1C ). The adipose fin rises very gradually (versus abruptly). The tip of the maxillary barbel is darker than the head.

Description

Head deep, with long, pointed snout. Maxillary barbel rather short, not reaching the eye in most (but not all) adults. Adipose fin high, at 8–13% SL. Branchiostegal membranes not fused; 9–10(11) branchiostegal rays. Width of premaxillary tooth plate 4.5–6.5% HL; both plates touching or not. Minimal caudal peduncle depth 8.5–11.5% SL. Dorsal fin with one rudimentary and one long spine, and 7 branched rays. Pectoral fin with spine and 9–10 branched rays, pelvic fin with 6 rays (5 branched), anal fin with 9–13 rays.

Colouration

Pigmentation from greyish brown to dark brown. Pattern variable, with marbled to often reticulate patterns covering body and fins in juveniles and many adults; other specimens with only one horizontal row of blurry spots on the body, bearing spots on the fins or not. Often a combination of both patterns. Tip of maxillary barbel markedly darker than head, often almost black.

Maximum size recorded

521 mm SL.

Distribution

Found throughout West African rivers from the Senegal River to the Cross and Chad basins, Congo basin including Lakes Mweru and Tanganyika, Nile, and rare reports from the Ethiopian Omo and Jubba Rivers. Absent in Lower Guinea ( Figure 9 ).

Note on type specimens of some synonymized taxa

Following the recommendations of the International Code of Zoological Nomenclature ( ICZN 1999: article 74), the following lectotypes are here designated for the nominal taxa synonymized with A. occidentalis . Location, quality and size of the specimen were paramount in the designations. For A. acuticeps , five syntypes were mentioned in the description by Pappenheim and Boulenger (1914), not seven, as later mentioned by Risch (1986) and Retzer (2010). An illustration of an unidentified syntype accompanied the description. One syntype (the largest?) apparently has been lost. Specimen ZMB 19094, the largest of the four syntypes (its standard length being 168 mm), is here considered as lectotype. The three syntypes of lot ZMB 21317 are now considered paralectotypes. For A. occidentalis tanganicanus , five syntypes were designated ( Boulenger 1906). An illustration of an unidentified syntype accompanied the description. The origin of the syntypes varied, with some being quite vague. The largest specimen in lot BMNH 1906.9.6.37–38 (296 mm SL), from Kalambo, Tanganyika, is here considered lectotype. The smaller specimen of the same lot, and the single specimens of lots BMNH 1906.9.6.39 and BMNH 1906.9.8.69, are here considered paralectotypes. For A. occidentalis tchadiensis , seven syntypes from the same locality were provided ( Pellegrin 1909). No syntype illustration has been published to date. The largest specimen, being the largest of lot MNHN 1909–425, is here considered lectotype (59 mm SL). The two other specimens of this lot, and the four specimens of lot MNHN 1909–426, are considered paralectotypes.

Figures

Figure 1. (A) Plot of principal components two and three (with percentage of total variance) of 31 log-transformed biometric data for 168 Auchenoglanis specimens; (B) plot of principal components two and three of 27 log-transformed biometric data for 168 Auchenoglanis specimens (all three barbel lengths, and combined premaxillary tooth plate width omitted); (C) ratio of postorbital to preorbital head length plotted against head length (measured until end of supraoccipital process) for 169 Auchenoglanis specimens. Type specimens are indicated by large symbols. For the A. biscutatus group: black circle: A. biscutatus holotype; grey circles: A. senegali types. For the A. occidentalis group: black triangle: A. occidentalis holotype; white triangles: A. o. tanganicanus types; white inverted triangles: A. acuticeps types; grey triangles: A. o. tchadiensis types; grey inverted triangles: A. wittei types. The Oxyglanis sacchii holotype is not included because its bad, dried state compromised many measurements.

Figure 8. (A) Holotype of Auchenoglanis biscutatus (MNHN 8969). (B) Holotype of Auchenoglanis occidentalis (MNHN 8971). Scale bars are 5 cm.

Figure 9. Confirmed localities of Auchenoglanis biscutatus and Auchenoglanis occidentalis. Symbols may represent multiple sampling locations. Locality of A. biscutatus holotype not exact (known locality: “Nile”).