A revision of the West African Hepsetus (Characiformes: Hepsetidae) with a description of Hepsetus akawo sp. nov. and a redescription of Hepsetus odoe (Bloch, 1794) Decru, E. Vreven, E. Snoeks, J. Journal of Natural History 2011 2012-01-31 46 1 - 2 1 23 3KWM8 (Bloch, 1794) Bloch 1794 [465,782,1133,1158] Actinopterygii Hepsetidae Hepsetus Animalia Characiformes 9 8 Chordata species odoe   Type material   Holotype: ZMB 3615, 149.4 mmSL, Coastof Guinea, provided by Dr Isert( Paepke 1999).  Diagnosis   Hepsetus odoecan be distinguished from all other  Hepsetusspeciesby the following unique combination of characters; number of lateral line scales, high: 50–60 (exceptionally 49); nostril-lower jaw distance, high: 40.4–47.6 (42.6) % HL (Figure 3); number of gill rakers on first arch, low: 14–22; number of scales between dorsal fin and lateral line: 71/ 2– 91/ 2; and number of scales between adipose fin and lateral line: 41/ 2– 61/ 2.  Description A representative specimen is illustrated in Figure 4. Maximum observed size: 350.0 mm SL. Meristic and morphometric data are given in respectively Tables 3and 4.  Figure 4. Lateral view of  Hepsetus odoe, representative specimen, 288.0 mm standard length, Gambia River (MRAC B0-16-P-1-10).  Table 3. Meristics for the holotype and all examined specimens of  Hepsetus odoe.    Meristics Holotype All examined specimens  Min. Max.  n Median  Lateral line scales 51 49 60 51 54  Scales between dorsal fin and lateral line Scales between adipose fin and lateral line 91/2 51/2 71/2 41/2 91/2 61/2 51 51 81/2 51/2  Scales between pelvic fin and lateral line 6 3 6 51 4  Scales between anal fin and lateral line 6 5 7 51 6  Pre-dorsal scales 17 16 22 51 19  Dorsal-adipose scales 20 18 23 51 20  Adipose-caudal scales 14 13 18 51 16  Epibranchial gill rakers on first gill arch – 5 10 48 7  Epibranchial gill plates on first gill arch – 0 6 48 3  Ceratobranchial gill rakers on first gill arch – 7 13 48 10  Ceratobranchial gill plates on first gill arch – 0 4 47 1  Gill rakers on first gill arch (UR/1/LR) – 14 22 48 18 Head intermediately broad, but relatively deep. Intermediate snout width and snout length compared with congeners. Body rather broad, more or less as broad as the head. Body form elongate, with dorsal and anal fins, though in a posterior position in all  Hepsetusspecies, more forward-positioned relative to the other  Hepsetus.High number of scales and an intermediate to high number of quite small gill rakers on the first gill arch.  Differential diagnosis   Hepsetus odoecan be distinguished from  H. akawoby a higher total number of lateral line scales [50–60 (exceptionally 49) vs 43–51], and by a longer nostril-lower jaw distance [40.4–47.6 (42.6) % HL vs 36.6–42.1 (39.6) % HL].  Table 4. Measurements for the holotype and all examined specimens of  Hepsetus odoe.    Holotype All examined specimens  Min. Max.  n Mean   Body measurements (% SL)  Pre-dorsal distance 64.7 62.0 69.6 51 65.8  Dorsal–adipose distance 12.2 10.0 13.9 51 12.1  Adipose–caudal distance 10.1 6.4 10.3 51 8.9  Pre-pelvic distance 31.8 27.8 33.6 51 30.0  Pelvic–pectoral distance 23.6 20.6 28.9 51 24.4  Pectoral–anal distance 25.2 19.1 25.2 51 22.2  Anal–caudal distance 10.6 8.9 12.7 51 10.3  Dorsal-fin base 10.7 10.0 13.5 51 11.5  Adipose-fin base 1.9 1.5 2.9 51 1.9  Pectoral-fin base 4.2 2.4 4.4 51 3.5  Pelvic-fin base 3.5 2.5 3.9 51 3.0  Anal-fin base 9.9 8.6 11.8 51 10.1  Pre-anal distance 75.9 72.9 79.8 34 76.9  Post-anal distance 24.8 22.0 26.4 51 23.8  Dorsal-fin height 24.1 20.1 29.0 48 23.2  Adipose-fin height 19.1 13.2 28.6 49 22.9  Pectoral-fin height 17.7 15.3 20.0 49 17.9  Pelvic-fin height 16.8 14.6 19.2 51 16.9  Anal-fin height 19.8 16.5 23.9 50 20.8  Caudal–peduncle distance 11.0 10.5 14.0 51 12.3  Caudal–peduncle depth 9.4 7.3 11.1 51 8.8  Body depth 22.6 15.6 25.6 50 19.7   Head measurements (% HL)  Head length 31.9 30.1 33.8 51 31.9  Nostril length 6.1 4.7 8.3 51 6.3  Nostril–eye distance 2.1 1.4 2.7 51 2.0  Snout length 38.4 36.4 40.1 51 38.4  Eye diameter 19.3 15.7 25.7 51 19.7  Head depth 43.9 41.4 49.0 51 44.6  Eye–lower jaw distance 26.3 20.8 33.7 51 27.1  Nostril–lower jaw distance 41.8 40.4 47.6 51 42.6  Lower jaw length 61.5 60.6 68.0 51 64.2  Upper jaw length 68.4 66.7 73.2 51 69.8  Head width 37.1 31.1 45.3 51 35.9  Interorbital distance 29.9 25.0 35.6 51 30.4  Internasal distance 21.2 19.5 25.3 51 22.3 Notes: SL, standard length; HL, head length.   Hepsetus odoecan be distinguished from  H. cuvieriby a higher number of gill rakers (14–22 vs 8–13), a lower number of scales between dorsal fin and lateral line ( 71/ 2– 91/ 2vs 101/ 2– 111/ 2); and a lower number of scales between adipose fin and lateral line ( 41/ 2– 61/ 2vs 61/ 2– 71/ 2).  Colouration (in alcohol) General colour pattern quite variable from light brownish with a yellow belly to a dark brownish colour all over the body. Dorsal surface of head and body darker than ventrally with a gradual change from darker to lighter tones on the flanks. Some specimens more uniformly coloured. A vague horizontal line pattern on the flanks, from anterior border of adipose fin (occasionally from posterior border of dorsal fin) to caudal fin base is sometimes present, resulting from the scales having a darker upper and lower border, while the remaining part of the scales remains paler. These lines cover the flanks from approximately three scale rows above down to two scale rows below the lateral line. Higher on the flanks, there is sometimes a mosaic pattern in the overall colour of the scales (darker and brighter scales alternating) from approximately three scales above the lateral line to eight lines above the lateral line. Sometimes series of 10 to 16 greyish vertical bands present on the dorsolateral body parts. The presence of these bands appears to be linked to stress (personal observation). Rounded dorsoventrally elongated blackish spot behind the head and just above the lateral line. Posterior part of head with three, well-marked, dark brownish bands running from posterior border of the eye to anterior edge of preopercle. Bands sometimes faded and poorly visible. Lower half of postopercle brownish, sometimes blackish. All fins but the adipose fin yellowish to dark brownish (more or less the same as body colour); distally translucent. Caudal fin translucent, in mid-centre and proximally on upper and lower lobes. Dorsal, anal and caudal fins with prominent small, roundish, darkbrown spots. Spots on fins more prominent on larger specimens (±> 150 mmSL). Some large specimens (±> 290 mmSL) with spots also on pelvic fins. Adipose fin base yellowish to darker brownish, black distally.  Distribution The distribution of  H. odoecovers the westernmost part of the distribution area of the genus ( Figure 5). The species is known from the region between the SenegalRiver ( Senegal) in the west to the Cavally River ( Ivory Coast) in the east.  Etymology The specific name is possibly derived from the Greek ‘ odon’ which means tooth ( Brown 1954).  Additional specimens examined (ordered by river system; all sizes as SL)   Senegal: MRAC 73-5-P-449; 226.0 mm; Dakar Bango, riv. Djeuss, près de St-Louis( 16 ◦03 ′N, 16 ◦29 ′W).  Casamance: MRAC 73-5-P-451-452; 198.5–202.5 mm; Guérina, marigot, bassin fl. Casamance ( 12 ◦46 ′N, 16 ◦15 ′W).   Gambia: MRAC 73-5-P-450., 289.5 mm; Georgetown, fl.  Gambie( 13 ◦31 ′N, 14 ◦45 ′W).  MRAC 81-03-P-282; 120.0 mm; Ba-Foula-Bé, riv.  Gambia( 13 ◦01 ′N, 13 ◦14 ′W).  MRAC 79-2-P-165-169; n= 3; 147.0–192.0 mm; Ba-Foula-Bé, riv.  Gambia( 13 ◦01 ′N, 13 ◦14 ′W).  MRAC 80-01-P-81-82; 195.5– 125.5 mm; Ba-Foula-Bé, riv.  Gambia( 13 ◦01 ′N, 13 ◦14 ′W).  Figure 5. Distribution of  Hepsetus odoeand  Hepsetus akawobased on the examined specimens from West Africa. Localities of  H. odoeindicated by open circles; and for  H. akawolarge filled triangle indicates type locality; smaller filled triangles indicate other localities.  Waanje: MRAC 73-10-P-966; 314.0 mm; Kalu, pêche dans le lac Mabesi et la riv. Malen ( 07 ◦14 ′N, 11 ◦45 ′W). Moa: MRAC 73-10-P-967; n= 2 (instead of one); 169.5–180.5 mm; near Moa River, north east of Kenema, marigots près de la Moa River, à 4–5 kmdu nord du pont ( 07 ◦52 ′N, 11 ◦08 ′W).  MRAC 73-10-P-971-974; n= 2; 125.5–174.5 mm; Pendehun, riv. Moa, à ± 3 kmen amont du pont ( 07 ◦51 ′N, 11 ◦09 ′W). Kogon:  MRAC 92-059-P-0648; 203.0 mm; Kamouri, riv. Batapon, affl. rio Nuñez( 11 ◦00 ′N, 14 ◦19 ′W).  MRAC 92-059-P-00657; 149.5 mm; Ndyarendi, riv. Kogon (± 11 ◦21 ′N, 14 ◦30 ′W).  MRAC 92-059-P-0649; 177.0 mm; Ndyarendi, riv. Kogon (± 11 ◦21 ′N, 14 ◦30 ′W).  MRAC 92-059-P-0650-0655; n= 5; 169.0–230.0 mm; Dabiss, riv. Aboulapon, affl. Kogon( 11 ◦11 ′N, 14 ◦32 ′W).  Kapatchez: MRAC 92-059-P-0636-0647; n= 11; 144.0–180.0 mm; rio Kapatchez, pont près de Songolon(Kakala) ( 10 ◦43 ′N, 14 ◦22 ′W).  Loffa: MRAC 73-10-P-975; 276.0 mm; Bombo-junction, marais et marigots à ± 16 kmà l’est de Mano, route Mano-Bomi Hills( 07 ◦22 ′N, 10 ◦53 ′W). MRAC 73-10-P- 976; 303.0 mm; bombo-junction, marais et marigots à ± 16 kmà l’est de Mano, route Mano-Bomi Hills( 07 ◦22 ′N, 10 ◦53 ′W).  St Paul: MRAC 73-10-P-977; 343.0 mm; Mount Coffee, St. Paulriv., lac de barrage ( 06 ◦32 ′N, 10 ◦35 ′W). St. John:  MRAC 80-36-P-814; 178.0 mm; Jusohn, Sangwinbekken ( 06 ◦04 ′N, 08 ◦37 ′W).  MRAC 73-10-P-978; 287.0 mm; Hartford, riv. St. John, en aval du pont et des premiers rapides ( 05 ◦59 ′N, 09 ◦59 ′W).  MRAC 80-36-P-815; 199.5 mm; Chesla, Sangwinbekken ( 06 ◦07 ′N, 08 ◦34 ′W).  MRAC 80-36-P-813; 131.5 mm; Jusohn, Sangwinbekken ( 06 ◦04 ′N, 08 ◦37 ′W). Cavally:  MRAC 80-36-P-812; 215.5 mm; Zleh Town, Cavalla basin ( 06 ◦13 ′N, 08 ◦25 ′W).  MRAC 80-19-P-42-43; 227.0–256.0 mm; riv. Cavallyen face du village de Tai( 05 ◦52 ′N, 07 ◦27 ′W).  MRAC 85-29-P-241-242; 209.0– 228.5 mm; Binhouye, riv. Nipoué ( 06 ◦47 ′N, 08 ◦19 ′W).  MRAC 73-10-P-963; 110.0 mm; Sahibli, riv. Cavally ( 06 ◦33 ′N, 08 ◦20 ′W).  MRAC 73-10-P-965; 140.4 mm; village Zoguiné, marigots du bassin de la riv. Cavally( 06 ◦32 ′N, 08 ◦28 ′W).  MRAC 73-10-P-959-960; 107.0– 130.5 mm; Sahibli, riv. Cavally ( 06 ◦33 ′N, 08 ◦20 ′W).  Additional specimens identified (ordered by river system; all sizes as SL)   Gambia: MRAC 73-5-P-456; 183.0 mm; Kounkane, riv. Kanyanga, tributaire de la riv. Geba( 12 ◦55 ′N, 14 ◦06 ′W). MRAC 81-03-P-283-284; 114.0– 130.5 mm; Kayanga riv. ( 12 ◦49 ′N, 14 ◦10 ′W). MRACB0-16-P-001-0010, 222.5–295.0 mm SL Rivière  Gambieau village Kani Kunda, situe à l’est de la ville de Farafenni(± 13 ◦33 ′N, 15 ◦24 ′W) Khady Diouf Goudiabyand MamadouN’diaye,  22 July 2010.  Cassamance: MRAC 73-5-P-453-455; 205.5–208.8 mm; Kolda, haut fl. Casamance( 12 ◦53 ′N, 14 ◦57 ′W).  Moa: MRAC 73-10-P-968-969; 64.6–107.5 mm; Pendehun, riv. Moa, à ± 3 kmen amont du pont ( 07 ◦51 ′N, 11 ◦09 ′W). MRAC 73-10-P-970; 67.0 mm; Pendehun, riv. Moa, à ± 3 kmen amont du pont ( 07 ◦51 ′N, 11 ◦09 ′W).  Kogon: MRAC 92-059-P-0656; 56.8 mm; Pabole, afflt. du Kogon( 11 ◦21 ′N, 14 ◦08 ′W). St John:  MRAC 80-36-P-801; 310 mm; L.  T.C. camp ( 06 ◦16 ′N, 08 ◦40 ′W).  MRAC 80-60-P-803-809; 113.0– 245.2 mm; Cestos, south of L.  T.C. (± 06 ◦16 ′N, 08 ◦43 ′W).  MRAC 80-36-P-810-811; 42.0– 43.2 mm; Duo Town( 05 ◦42 ′N, 08 ◦06 ′W).  MRAC 80- 36-P-802; 106.0 mm; Duzei, Cestosbekken ( 06 ◦16 ′N, 08 ◦42 ′W).  Nipoué: MRAC 73-10-P-964; 112.5 mm; Toyebli, riv. Cess ( 06 ◦38 ′N, 08 ◦29 ′W). MRAC 86-18-P-336-337; 113.0– 132.5 mm; Binhouye, riv. Nipoué ( 06 ◦47 ′N, 08 ◦19 ′W).  Cavally: MRAC 73-10-P-962; 293.3 mm; Sahibli, riv. Cavally ( 06 ◦33 ′N, 08 ◦20 ′W). ZMB Guinea-Bissau Coast Dr Isert 9 8 1 holotype MRAC Bango & Djeuss & de St-Louis Senegal 16.05 Dakar 1283 -16.483334 12 11 MRAC 73-5 1 Dakar MRAC 12.766666 1292 -16.25 12 11 MRAC 73-5 1 [254,931,1538,1562] MRAC Gambia Gambia 12 11 MRAC 73-5 1 Gambia 13.516666 Gambie 1290 -14.75 12 11 1 [348,932,1570,1594] MRAC Gambia 12 11 MRAC 81-03 1 Gambia 13.016666 Gambia 1291 -13.233334 12 11 1 [336,1070,1602,1626] MRAC Gambia 12 11 MRAC 79-2 1 Gambia 13.016666 Gambia 1291 -13.233334 12 11 1 [484,1168,1634,1658] MRAC Gambia 12 11 MRAC 80-01 1 [211,545,1662,1690] Gambia 13.016666 Gambia 1291 -13.233334 12 11 1 MRAC 7.233333 1303 -11.75 13 12 MRAC 73-10 1 MRAC de la Moa 7.866667 Kenema 1302 -11.133333 13 12 MRAC 73-10 1 Rivers MRAC 7.85 1302 -11.15 13 12 MRAC 73-10 1 Rivers MRAC Kamouri & Batapon 11.0 rio Nunez 1296 -14.316667 13 12 MRAC 92-059 1 MRAC Ndyarendi 11.35 1295 -14.5 13 12 MRAC 92-059 1 MRAC Ndyarendi 11.35 1295 -14.5 13 12 MRAC 92-059 1 MRAC 11.183333 Aboulapon 1295 -14.533334 Kogon 13 12 MRAC 92-059 1 MRAC de Songolon 10.716666 rio Kapatchez 1297 -14.366667 13 12 MRAC 92-059 1 MRAC Bombo-junction & de Mano & Mano-Bomi Hills 7.366667 1303 -10.883333 13 12 MRAC 73-10 1 MRAC 6.5333333 Mount Coffee 1304 -10.583333 St. Paul 13 12 MRAC 73-10 1 MRAC 6.0666666 Jusohn 1305 -8.616667 Sangwin 13 12 MRAC 80-36 1 MRAC 5.9833336 Hartford 1305 -9.983334 St. John 13 12 MRAC 73-10 1 MRAC 6.116667 Chesla 1305 -8.566667 Sangwin 13 12 MRAC 80-36 1 MRAC 6.0666666 Jusohn 1305 -8.616667 Sangwin 13 12 MRAC 80-36 1 MRAC 6.2166667 Zleh Town 1305 -8.416667 13 12 MRAC 80-36 1 MRAC de Tai 5.866667 Cavally 1305 -7.45 13 12 MRAC 80-19 1 MRAC 6.7833333 Binhouye 1304 -8.316667 13 12 MRAC 85-29 1 MRAC 6.55 Sahibli 1304 -8.333333 13 12 MRAC 73-10 1 MRAC Cavally 14 13 6.5333333 Zoguine 1304 -8.466666 13 12 MRAC 73-10 1 MRAC 6.55 Sahibli 1304 -8.333333 14 13 MRAC 73-10 1 MRAC SL Riviere Gambia Geba 12.816667 Kounkane 1292 -14.166667 Kanyanga 14 13 MRAC 73-5, MRAC 81-03 1 2010-07-22 de Farafenni & Khady Diouf Goudiaby & Mamadou Gambia 13.55 Kani Kunda 1290 -15.4 14 13 1 MRAC 12.883333 Casamance 1292 -14.95 14 13 MRAC 73-5 1 Kolda MRAC 7.85 1302 -11.15 14 13 MRAC 73-10 1 MRAC Pabole & du Kogon 11.35 1295 -14.133333 14 13 MRAC 92-059 1 [351,715,702,726] MRAC 14 13 MRAC 80-36 1 [719,1076,698,726] T 6.266667 1304 -8.666667 14 13 1 MRAC Cestos 14 13 MRAC 80-60 1 [841,1167,730,758] T 6.266667 1304 -8.716666 14 13 1 [211,1034,762,790] MRAC 5.7 Duo Town 1305 -8.1 14 13 MRAC 80-36 1 MRAC 6.266667 Duzei 1304 -8.7 Cestos 14 13 MRAC 80- 36 1 MRAC 6.7833333 1304 -8.316667 14 13 MRAC 73-10, MRAC 86-18 1 [254,1167,921,949] MRAC 6.55 1304 -8.333333 14 13 MRAC 73-10 1