taxonID	type	description	language	source
C3CF1068CD1DF57D972672B3F9ABF4CB.taxon	discussion	The genus Microsynodontis is restricted to the rivers of western Africa (from the Saint Paul River drainage south and east to the Congo River drainage), and is comprised of small mochokid catfishes diagnosed by the following synapomorphies: a narrow mesethmoid, lack of free orbital margin, transverse ventral fold of branchiostegal membranes, slender cleithral process, and a rounded or truncate caudal fin (Howes, 1980). Currently, there are four nominal species of Microsynodontis, viz. M. batesii Boulenger, 1903, M. christyi Boulenger, 1920, M. lamberti Poll & Gosse, 1963 and M. polli Lambert, 1958. Microsynodontis christyi has been considered a junior synonym of M. batesii (fide Matthes, 1964), but is a valid species. The freshwater ichthyofauna of the lower Guinea region (here defined as the portion of west central Africa delineated by the Cross River drainage to the north and the Chiloango River drainage to the south; fide Roberts, 1975) is one of the least explored in Africa (Teugels & Guegan, 1994). Microsynodontis batesii is the only species known from there. While preparing an account of Microsynodontis for a forthcoming publication on the fishes of the lower Guinea region (Ng, in prep.), it was found that material from the region previously identified as M. batesii consisted of nine distinct species, eight of which are undescribed. This study reviews the Microsynodontis of the lower Guinea region, with the eight new species described herein.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
C132F991958160BAE1DA51CEC566C682.taxon	description	(Fig. 1)	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
C132F991958160BAE1DA51CEC566C682.taxon	materials_examined	Material. AMNH 232091 (1), female: 34.6 mm SL; Gabon: Ivindo River drainage, Minkebe gold camp forest, 1 ° 43 ' 38.2 " N 12 ° 48 ' 35.8 " E. BMNH 1903.7.28.105 - 110 (6), 3 syntype females: 48.8 - 58.3 mm SL, 3 syntype males: 75.7 - 84.7 mm SL; Cameroon: Mvile River. CAS 115547 (1), male: 37.7 mm SL; Cameroon: Mvila River drainage, Menyoo River, Ebolowa, 2 ° 53 ' N 11 ° 9 ' E. CAS 147487 (2), unsexed: 18.5 mm SL; Cameroon: Ntem or Campo River drainage, Mfiande and Seng Rivers. CAS 155689 (1), male: 57.8 mm SL; Cameroon: Ntem River drainage, Mboto River at Assok, 74 km SE of Ebolowa, 2 ° 34 ' N 11 ° 30 ' E. CAS 155691 (4), 2 females: 52.8 - 53.4 mm SL; 2 males: 65.5 - 66.0 mm SL; Cameroon: Ntem River drainage, Mboto River at Mekomo, 37 km E of Ebolowa, 2 ° 37 ' N 11 ° 22 ' E. CU 80445 (1), male: 48.0 mm SL; Gabon: Woleu-Ntem province, “ Bouth ” creek where it crosses road from Bitam - Minvoul, 2 ° 15 ' N 11 ° 39 ' E. CU 80748 (8), males: 20.3 - 35.4 mm SL; Gabon: Woleu-Ntem province, “ Deghe ” creek near Auberge d’Ayengbe, 2 ° 17 ' N 11 ° 33 ' E. MCZ 32521 (1), female: 59.4 mm SL; Cameroon: Nyong River. MRAC 93 - 085 - P- 0279 - 0280 (2); females, 28.2 - 42.6 mm SL; Cameroon: Mboro River (tributary of Ntem River) at Akonekye, 2 ° 28 ' N 11 ° 10 ' E. MRAC 93 - 108 - P- 0651 - 0655 (5), 3 females: 21.5 - 26.5 mm SL; 2 males: 27.0 - 29.8 mm SL; Cameroon: Mengounou River, tributary of Mboua River, in Bilizi between Befio and Ekowong, 2 ° 32 ' N 12 ° 11 ' E. MRAC 93 - 108 - P- 0656 (1), male: 24.9 mm SL; Cameroon: river located 4 km from Akobass in the direction of Bitche, 2 ° 22 ' N 12 ° 4 ' E. MRAC 93 - 108 - P- 0657 (1), male: 22.8 mm SL; Cameroon: river after Aboulou in the direction of Mebang, 2 ° 19 ' N 12 ° 4 ' E. MRAC 93 - 108 - P- 0658 (1), male: 21.0 mm SL; Cameroon: Yete River, tributary of Kom River after Mebasa and before Ngoudjieng, 2 ° 29 ' N 12 ° 13 ' E. MRAC 93 - 108 - P- 0659 (1), male: 28.2 mm SL; Cameroon: Milolo River, tributary of Kom River between Esaminkou and Andoung, 2 ° 27 ' N 12 ° 20 ' E. MRAC 94 - 028 - P- 0002 (1), male: 34.4 mm SL; Cameroon: Anga’a River, approximately 10 km from Yaounde, 3 ° 52 ' N 11 ° 31 ' E. MRAC 95 - 030 - P- 1443 - 1448 (6), 1 female: 27.0 mm SL, 5 unsexed: 17.4 - 21.2 mm SL; Cameroon: first river at confluence at Mvangan, towards Nelefoup, 2 ° 39 ' N 11 ° 44 ' E. MRAC 95 - 030 - P- 1443 - 1448 (4), 17.4 - 27.0 mm SL, Cameroon: Mvong River, tributary of Kong River, 2 ° 48 ' N 11 ° 39 ' E. MRAC 95 - 030 - P- 1453 - 1454 (2), 1 male: 26.0 mm SL; 1 unsexed: 17.3 mm SL; Cameroon: Otobewo’o River, tributary of Woo River, between Ekombite and Nkolenyeng, 2 ° 40 ' N 11 ° 46 ' E. RMNH 34859 (8), 6 females: 36.1 - 65.6 mm SL; 2 males: 49.2 - 74.8 mm SL; Cameroon: Lobe River, waterfalls 9 km S of Kribi.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
C132F991958160BAE1DA51CEC566C682.taxon	diagnosis	Diagnosis. Microsynodontis batesii is the largest known species of Microsynodontis, reaching a size of ca. 100 mm SL (the largest specimen among all other congeners is only ca. 65 mm SL). It can be distinguished from all congeners except M. hirsutus, M. laevigatus and M. polli in having a longer adipose fin (34.4 - 41.6 % SL vs. 21.3 - 34.5). It differs from M. hirsutus in having in having a gently curved (vs. straight) dorsal spine (Fig. 2) and short (vs. long) tubercles on the dorsal and lateral surfaces of the head (Fig. 3), from M. laevigatus in having a serrated (vs. smooth) anterior edge of the pectoral spine (Fig. 4), rounded (vs. truncate) caudal fin (Fig. 9), and more slender caudal peduncle (5.8 - 9.2 % SL vs. 9.3 - 11.4), and from M. polli (n = 9) in having a shorter caudal fin (20.3 - 27.7 % SL vs. 29.6 - 41.6).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
C132F991958160BAE1DA51CEC566C682.taxon	description	Description. Biometric and meristic data as in Table 1. Body compressed. Predorsal profile gently convex; postdorsal body sloping gently ventrally. Preanal profile horizontal. Anus and urogenital openings located at vertical through middle of pelvic fin. Skin smooth. Lateral line complete and midlateral. Head depressed and broad, broadly rounded when viewed laterally and with rounded snout margin when viewed from above. Gill openings narrow, extending from immediately ventral to posttemporal to immediately ventral to base of pectoral spine. Gill membranes united to, and attached across, isthmus. Bony elements of dorsal surface of head covered with thin skin. Nuchal shield large and terminating posteriorly with two rounded processes on each side. Supracleithral process thin and extending just short of vertical through posteriormost tip of nuchal shield. Barbels in three pairs. Maxillary barbel long and slender, extending to just beyond base of last pectoral-fin ray. Inner mandibular-barbel origin close to midline, extending to base of pectoral spine and with 2 short, thin branches on anterior half and 3 - 5 long, thin branches on posterior half. Outer mandibular barbel originates posterolateral of inner mandibular barbel, extending to middle of pectoral-fin base and with 3 - 5 long, thin branches. Eye ovoid, horizontal axis longest; located entirely in dorsal half of head. Orbit without free margin. Mouth inferior and crescent-shaped; lips plicate. Oral teeth in rows on all tooth-bearing surfaces. Premaxillae narrow, with narrow ventral shelf and partially exposed when mouth closed. Primary teeth 10 - 15, conical and separated from secondary teeth by distinct gap. Secondary teeth 40 - 85, acutely pointed and recurved; disposed in 3 - 4 rows. Tertiary teeth 17 - 29, elongate, villiform and extending over full width of premaxillae. Dentary teeth 17 - 28, acutely pointed, strongly recurved and broader than secondary teeth; disposed in one or two transverse bands. Dorsal fin located at anterior third of body, with convex margin and II, 6 (39) or II, 7 (3) rays. Dorsal-fin spine long, stout and slightly curved; smooth on both anterior and posterior margins. Adipose fin long, extending for most of postdorsal distance; margin slightly convex for entire length and posterior end deeply incised. Caudal fin rounded, with i, 6,5, i (26) or i, 6,6, i (16) principal rays. Procurrent rays symmetrical and extend only slightly anterior to fin base. Anal-fin base located ventral to posterior half of adipose fin. Anal fin with iv, 7 (30); iv, 8 (9); iv, 9 (2) or iv, 10 (1) rays and convex margin. Pelvic-fin origin at vertical ventral to posterior end of dorsal-fin base. Pelvic fin with i, 6 (42) rays and slightly convex margin; tip of appressed fin not reaching anal-fin origin. Pectoral fin with I, 5, i (13); I, 6 (28) or I, 6, i (1) rays; spine slightly curved and stout (Fig. 4 f). Anterior spine margin with 22 - 33 small serrations along entire length of spine; serrations antrorse (distally directed) on distal two-thirds and anteriorly directed on proximal third. Posterior spine margin with 6 - 14 strong serrations along entire length. Pectoral-fin margin convex posteriorly. Vertebrae 13 + 22 = 35 (6); 11 + 25 = 36 (1); 12 + 24 = 36 (4); 13 + 23 = 36 (3); 14 + 22 = 36 (2); 12 + 25 = 37 (5); 13 + 24 = 37 (4); 12 + 26 = 38 (2); 13 + 25 = 38 (7) or 14 + 23 = 37 (1). Males with numerous tubercles on sides of head on region extending from snout to preopercle, and long genital papilla situated immediately posterior to anus. Females with fewer tubercles on sides of head, and with smaller, distally flattened genital papilla. Coloration. In 70 % ethanol (adults larger than ca. 35 mm SL): dorsal and lateral surfaces and of head and body medium brown, fading to cream or light grayish brown on ventral third of body, belly (with large faint brown spots), and ventral surface of head (Fig. 1 a). Snout with a series of cream spots delineating anterior and posterior nares, sometimes coalescing to form cream band running from anterior orbital margin to tip of snout. Cheek region with one or two cream spots immediately ventral to orbit. Cream band encircling nape at supraoccipital. Dorsal third of body with series of four cream vertical bar-shaped marks extending beyond lateral midline of body: first at middle of dorsal-fin base, second at adipose-fin origin, third at middle of adipose-fin base and last on caudal peduncle immediately posterior to adipose fin, sometimes encircling caudal peduncle as cream band. Ventral third of flanks with a longitudinal series of five to seven cream spots or vertical bar-shaped marks. Dorsal-, pectoral-, pelvic- and anal-fin rays with brown spots arranged in two or three bands. Caudal-fin rays with brown spots arranged in four bands and hyaline interradial membranes. Live coloration similar, with the addition of a faint dark reticulate pattern overlying the body (Fig. 1 b). Coloration of juveniles (smaller than ca. 35 mm SL) similar, except for more prominent brown spotting on ventral surfaces, and larger cream markings that sometimes assume more vermiform shapes, partially coalescing to form reticulate pattern (Fig. 1 c). Pectoral fins hyaline, with scattered brown spots. Dorsal, anal and caudal fin with brown spots arranged in transverse bands.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
C132F991958160BAE1DA51CEC566C682.taxon	distribution	Distribution. Known from the Ntem River drainage in southern Cameroon and northern Gabon, as well as the Campo, Ivindo, Lobe, Nyong and Sanaga River drainages in southern and central Cameroon (Fig. 5). Remarks. Although M. batesii appears to have a much wider distribution compared to all other Microsynodontis from lower Guinea (Figs. 5, 7 & 13), it is possible that more than one species is involved in what is recognized as M. batesii here. In particular, the populations from the northernmost extent of its distribution (i. e. from the Nyong and Sanaga River drainages) should be further studied to verify their conspecificity with the material from southern Cameroon and northern Gabon, but the paucity of relevant material available for study does not allow for more a more conclusive test of this hypothesis.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
630F52D9B165F1D123C625BC18B2A658.taxon	description	(Fig. 6)	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
630F52D9B165F1D123C625BC18B2A658.taxon	diagnosis	Diagnosis. Microsynodontis armatus can be distinguished from all congeners in having retrorse (proximally directed) serrations (vs. smooth or with either anteriorly directed or antrorse (distally directed) serrations) along the proximal third of the anterior edge of the pectoral spine (Fig. 4 a).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
630F52D9B165F1D123C625BC18B2A658.taxon	description	Description. Biometric and meristic data as in Table 2. Body compressed. Predorsal profile gently convex; postdorsal body sloping gently ventrally. Preanal profile horizontal. Anus and urogenital openings located at vertical through middle of pelvic fin. Skin smooth. Lateral line complete and midlateral. Head depressed and broad, broadly rounded when viewed laterally and with rounded snout margin when viewed from above. Gill openings narrow, extending from immediately ventral to posttemporal to immediately ventral to base of pectoral spine. Gill membranes united to, and attached across, isthmus. Bony elements of dorsal surface of head covered with thin skin. Nuchal shield large and terminating posteriorly with two rounded processes on each side. Supracleithral process thin, extending just short of vertical through posteriormost tip of nuchal shield. Barbels in three pairs. Maxillary barbel long and slender, extending to just beyond base of last pectoral-fin ray. Inner mandibular-barbel origin close to midline, extending to base of pectoral spine and with 2 short, thin branches on anterior half and 3 - 4 long, thin branches on posterior half. Outer mandibular barbel originates posterolateral of inner mandibular barbel, extending to middle of pectoral-fin base and with 3 - 4 long, thin branches. Eye ovoid, horizontal axis longest; located entirely in dorsal half of head. Orbit without free margin. Mouth inferior and crescent-shaped; lips plicate. Oral teeth in rows on all tooth-bearing surfaces. Premaxillae narrow, with narrow ventral shelf and partially exposed when mouth closed. Primary teeth 11 - 12, conical and separated from secondary teeth by distinct gap. Secondary teeth 35 - 50, acutely pointed and recurved; disposed in 3 - 4 rows. Tertiary teeth 16 - 20, elongate, villiform and extending over full width of premaxillae. Dentary teeth 14 - 18, acutely pointed, strongly recurved and broader than secondary teeth; disposed in one or two transverse bands. Dorsal fin located at anterior third of body, with II, 5, i (2) or II, 6 * (1) rays and convex margin. Dorsal-fin spine short, stout and slightly curved; smooth on both anterior and posterior margins. Adipose fin moderately long; margin slightly convex for entire length and posterior end deeply incised. Caudal fin rounded, with i, 6,5, i (3) principal rays. Procurrent rays symmetrical and extend only slightly anterior to fin base. Anal-fin base located ventral to posterior half of adipose fin. Anal fin with iv, 7 (3) rays and convex margin. Pelvic-fin origin at vertical ventral to posterior end of dorsal-fin base. Pelvic fin with i, 6 (3) rays and slightly convex margin; tip of appressed fin not reaching anal-fin origin. Pectoral fin with I, 6 (3) rays; spine slightly curved and stout (Fig. 4 a). Anterior spine margin with 21 - 27 small serrations along entire length of spine; serrations antrorse (distally directed) on distal two-thirds and retrorse (proximally directed) on proximal third. Posterior spine margin with 6 - 12 strong serrations along entire length. Pectoral-fin margin convex posteriorly. Vertebrae 12 + 22 = 34 (1); 13 + 21 = 34 (1) or 12 + 23 = 35 (1). Males with numerous tubercles on sides of head on region extending from snout to preopercle, and long genital papilla situated immediately posterior to anus. Females with fewer tubercles on sides of head, and with smaller, distally flattened genital papilla.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
630F52D9B165F1D123C625BC18B2A658.taxon	description	Coloration. In 70 % ethanol: dorsal and lateral surfaces and of head and body medium brown, fading to cream on belly and ventral surfaces (Fig. 6). Medium-sized brown spots evenly scattered over ventral surfaces. Snout with a series of cream spots delineating anterior and posterior nares, sometimes coalescing to form cream band running from anterior orbital margin to tip of snout. Cheek region with numerous small cream spots ventral and posterior to orbit. Cream band encircling nape at supraoccipital. Dorsal third of body with series of four cream irregular blotches extending short of lateral midline of body: first at middle of dorsal-fin base, second at adipose-fin origin, third at middle of adipose-fin base and last on caudal peduncle immediately posterior to adipose fin, sometimes coalescing with similar marks ventrally and encircling caudal peduncle as irregular cream band. Ventral third of flanks with a series of irregular cream blotches sometimes coalescent with dorsal markings to form reticulate pattern. Dorsal, pectoral, pelvic and anal fins hyaline and sometimes with one to two rows of faint spots forming longitudinal brown rows. Caudal fin with similar series of elongate marks forming two to three irregular columns.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
630F52D9B165F1D123C625BC18B2A658.taxon	distribution	Distribution. Known only from the Ivindo River in northern Gabon (Fig. 7).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
630F52D9B165F1D123C625BC18B2A658.taxon	biology_ecology	Habitat. The type locality is a blackwater forest stream with sand and leaf litter bottom. Water temperature was 22.0 ° C and the pH was 5.0. Syntopic fish included: Mormyridae: Brienomyrus spp., Isichthys henryi, Marcusenius moorii, Mormyrops zanclirostris, Petrocephalus christyi, Characidae: Brycinus kingsleyae; Distichodontidae: Distichodus notospilus, Nannocharax fasciatus; Cyprinidae: Barbus spp., Opsaridium ubangense, Raiamas buchholzi, Clariidae: Clarias sp.; Claroteidae: Parauchenoglanis balayi; Schilbeidae: Schilbe laticeps; Mochokidae: Synodontis batesii; Cichlidae: Hemichromis fasciatus, Parananochromis sp., Tilapia sp.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
630F52D9B165F1D123C625BC18B2A658.taxon	etymology	Etymology. From the Latin armatus, meaning armed. In allusion to the antrorse (distally directed) and retrorse (proximally directed) serrations on the anterior edge of the pectoral spine unique to this species. Used as a noun in apposition.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
170CAA05403DED7992F4BFDF7BEA2282.taxon	description	(Fig. 8)	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
170CAA05403DED7992F4BFDF7BEA2282.taxon	diagnosis	Diagnosis. Microsynodontis emarginatus can be distinguished from all congeners in having an emarginate (vs. rounded or truncate) caudal fin (Fig. 9). It also exhibits no noticeable sexual dimorphism in the size and density of the tubercles on the dorsal and lateral surfaces of the head, unlike all other lower Guinea species of Microsynodontis.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
170CAA05403DED7992F4BFDF7BEA2282.taxon	description	Description. Biometric and meristic data as in Table 3. Body compressed. Predorsal profile gently convex; postdorsal body sloping gently ventrally. Preanal profile horizontal. Anus and urogenital openings located at vertical through middle of pelvic fin. Skin smooth. Lateral line complete and midlateral. Head depressed and broad, broadly rounded when viewed laterally and with rounded snout margin when viewed from above. Gill openings narrow, extending from immediately ventral to posttemporal to immediately ventral to base of pectoral spine. Gill membranes united to, and attached across, isthmus. Bony elements of dorsal surface of head covered with thin skin. Nuchal shield large and terminating posteriorly with two rounded processes on each side. Supracleithral process thin, extending just short of vertical through posteriormost tip of nuchal shield. Barbels in three pairs. Maxillary barbel long and slender, extending to just beyond base of last pectoral-fin ray. Inner mandibular-barbel origin close to midline, extending to base of pectoral spine and with 2 short, thin branches on anterior half and 3 - 5 long, thin branches on posterior half. Outer mandibular barbel originates posterolateral of inner mandibular barbel, extending to middle of pectoral-fin base and with 3 - 5 long, thin branches. Eye ovoid, horizontal axis longest; located entirely in dorsal half of head. Orbit without free margin. Mouth inferior and crescent-shaped; lips plicate. Oral teeth in rows on all tooth-bearing surfaces. Premaxillae narrow, with narrow ventral shelf and partially exposed when mouth closed. Primary teeth 9 - 11, conical and separated from secondary teeth by distinct gap. Secondary teeth 35 - 50, acutely pointed and recurved; disposed in 3 - 4 rows. Tertiary teeth 15 - 24, elongate, villiform and extending over full width of premaxillae. Dentary teeth 15 - 21, acutely pointed, strongly recurved and broader than secondary teeth; disposed in one or two transverse bands. Dorsal fin located at anterior third of body, with II, 7 (30) rays and convex margin. Dorsal-fin spine long, stout and slightly curved; smooth on both anterior and posterior margins. Adipose fin moderately long; margin slightly convex for entire length and posterior end deeply incised. Caudal fin emarginate (Fig. 10 a), with i, 6,5, i (3) or i, 6,6, i * (27) principal rays. Procurrent rays symmetrical and extend only slightly anterior to fin base. Anal-fin base located ventral to posterior half of adipose fin. Anal fin with iv, 6 (1); iv, 7 * (22) or iv, 8 (7) rays and convex margin. Pelvic-fin origin at vertical ventral to posterior end of dorsal-fin base. Pelvic fin with i, 6 (30) rays and slightly convex margin; tip of appressed fin not reaching anal-fin origin. Pectoral fin with I, 6 (30) rays; spine slightly curved and stout (Fig. 4 c). Anterior spine margin with 15 - 22 small serrations along entire length of spine; serrations antrorse (distally directed) on distal two thirds and anteriorly directed on proximal third. Posterior spine margin with 7 - 9 strong serrations along entire length. Pectoral-fin margin convex posteriorly. Vertebrae 13 + 22 = 35 (1); 12 + 24 = 36 (3); 13 + 23 = 36 * (18); 13 + 24 = 37 (6); 14 + 22 = 36 (1) or 14 + 23 = 37 (1). No marked sexual dimorphism in the size and density of tubercles on head. Males with long genital papilla situated immediately posterior to anus. Females with smaller, distally flattened genital papilla. Coloration. In 70 % ethanol: dorsal and lateral surfaces and of head and body medium brown, fading to cream or light grayish brown on ventral third of body, belly (with large faint brown spots), and ventral surface of head (Fig. 8). Snout with a series of cream spots delineating anterior and posterior nares, sometimes coalescing to form cream band running from anterior orbital margin to tip of snout. Cheek region with one or two cream spots immediately ventral to orbit. Cream band encircling nape at supraoccipital. Dorsal third of body with series of four cream vertical bar-shaped marks extending beyond lateral midline of body: first at middle of dorsal-fin base, second at adipose-fin origin, third at middle of adipose-fin base and last on caudal peduncle immediately posterior to adipose fin, sometimes encircling caudal peduncle as cream band. Ventral third of flanks with a longitudinal series of five to seven cream spots or vertical bar-shaped marks. Dorsal, pectoral, pelvic and anal fins hyaline and sometimes with one to two rows of faint spots forming longitudinal brown rows. Caudal fin with similar series of elongate marks forming two to three irregular columns.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
170CAA05403DED7992F4BFDF7BEA2282.taxon	distribution	Distribution. Known from the upper Ogooue River in southeastern Gabon (Fig. 7).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
170CAA05403DED7992F4BFDF7BEA2282.taxon	biology_ecology	Habitat. The type locality is a very slow-flowing creek. Water temperature was 25.4 ° C and the pH was 5.0. Syntopic fish included: Mormyridae: Brienomyrus spp., Marcusenius moorii, Mormyrops zanclirostris, Stomatorhinus walkeri; Characidae: Brycinus sp.; Distichodontidae: Distichodus sp., Nannocharax sp.; Hepsetidae: Hepsetus odoe; Cyprinidae: Barbus spp.; Amphiliidae: Amphilius nigricaudatus, Phractura sp., Clariidae: Clarias spp.; Claroteidae: Parauchenoglanis balayi; Mochokidae: Synodontis sp.; Cyprinodontidae: Plataplochilus terveri; Channidae: Parachanna insignis; Cichlidae: Hemichromis sp.; Anabantidae: Ctenopoma kingsleyae; Mastacembelidae: Caecomastacembelus sp.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
170CAA05403DED7992F4BFDF7BEA2282.taxon	etymology	Etymology. From the Latin emarginatus, meaning notched at the apex; in reference to distinctive shape of the caudal fin. Used as an adjective.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
06D5EEECFADF9110E6A10A63AF29C033.taxon	description	(Fig. 10)	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
06D5EEECFADF9110E6A10A63AF29C033.taxon	diagnosis	Diagnosis. Microsynodontis hirsutus can be distinguished from all congeners in having long (vs. short) tubercles on the dorsal and lateral surfaces of the head (Fig. 3) and a straight (vs. gently curved) dorsal spine (Fig. 2). The tubercles are typically 0.3 mm long in the holotype of M. hirsutus, while in similar-sized specimens of other Microsynodontis, they are about 0.05 mm long; the smaller paratype male of M. hirsutus (28.0 mm SL) has tubercles 0.1 mm long, as compared to 0.05 mm in other male congeners of similar size. The tubercles are 0.05 mm in the larger paratype female, as compared to 0.02 mm in female congeners of the same size. It further differs from congeners except M. batesii and M. polli in having a longer adipose fin (34.6 - 37.9 % SL vs. 21.3 - 35.5). It can be further distinguished from M. polli (n = 9) in having a shorter caudal fin (20.0 - 24.3 % SL vs. 29.6 - 41.6).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
06D5EEECFADF9110E6A10A63AF29C033.taxon	description	Description. Biometric and meristic data as in Table 4. Body compressed. Predorsal profile gently convex; postdorsal body sloping gently ventrally. Preanal profile horizontal. Anus and urogenital openings located at vertical through middle of pelvic fin. Skin smooth. Lateral line complete and midlateral. Head depressed and broad, acutely rounded when viewed laterally and with rounded snout margin when viewed from above. Gill openings narrow, extending from immediately ventral to posttemporal to immediately ventral to base of pectoral spine. Gill membranes united to, and attached across, isthmus. Bony elements of dorsal surface of head covered with thin skin. Nuchal shield large and terminating posteriorly with two rounded processes on each side. Supracleithral process thin, extending just short of vertical through posteriormost tip of nuchal shield. Barbels in three pairs. Maxillary barbel long and slender, extending to just beyond base of last pectoral-fin ray. Inner mandibular-barbel origin close to midline, extending to base of pectoral spine and with 2 short, thin branches on anterior half and 3 - 5 long, thin branches on posterior half. Outer mandibular barbel originates posterolateral of inner mandibular barbel, extending to middle of pectoral-fin base and with 3 - 5 long, thin branches. Eye ovoid, horizontal axis longest; located entirely in dorsal half of head. Orbit without free margin. Mouth inferior and crescent-shaped; lips plicate. Oral teeth in rows on all tooth-bearing surfaces. Premaxillae narrow, with narrow ventral shelf and partially exposed when mouth closed. Primary teeth 14 - 21, conical and separated from secondary teeth by distinct gap. Secondary teeth 40 - 85, acutely pointed and recurved; disposed in 3 - 4 rows. Tertiary teeth 19 - 28, elongate, villiform and extending over full width of premaxillae. Dentary teeth 17 - 25, acutely pointed, strongly recurved and broader than secondary teeth; disposed in one or two transverse bands. Dorsal fin located at anterior third of body, with II, 7 (4) rays and convex margin. Dorsal-fin spine long, stout and straight; smooth on both anterior and posterior margins. Adipose fin long, extending for most of postdorsal distance; margin slightly convex for entire length and posterior end deeply incised. Caudal fin rounded, with i, 6,6, i (4) principal rays. Procurrent rays symmetrical and extend only slightly anterior to fin base. Anal-fin base located ventral to posterior half of adipose fin. Anal fin with iv, 7 * (2) or iv, 8 (2) rays and convex margin. Pelvic-fin origin at vertical ventral to posterior end of dorsal-fin base. Pelvic fin with i, 6 (4) rays and slightly convex margin; tip of appressed fin not reaching anal-fin origin. Pectoral fin with I, 6 (4) rays; spine slightly curved and stout (as in Fig. 4 f). Anterior spine margin with 12 - 35 small serrations along entire length of spine; serrations antrorse (distally directed) on distal two-thirds and anteriorly directed on proximal third. Posterior spine margin with 9 - 13 strong serrations along entire length. Pectoral-fin margin convex posteriorly. Vertebrae 12 + 24 * (3) or 13 + 24 (1). Males with numerous tubercles on sides of head on region extending from snout to preopercle, and long genital papilla situated immediately posterior to anus. Females with fewer tubercles on sides of head, and with smaller, distally flattened genital papilla. Coloration. In 70 % ethanol (adults larger than ca. 30 mm SL): dorsal and lateral surfaces and of head and body brownish gray, fading to dirty cream on ventral third of body, belly (with faint traces of brownish gray spots), and ventral surface of head (Fig. 10). Snout with a series of cream spots delineating anterior and posterior nares. Cheek region with one or two cream spots immediately ventral to orbit. Cream band encircling nape at supraoccipital. Dorsal third of body with series of four cream vertical bar-shaped marks extending beyond lateral midline of body: first at middle of dorsal-fin base, second at adipose-fin origin, third at middle of adipose-fin base and last on caudal peduncle immediately posterior to adipose fin, sometimes encircling caudal peduncle as cream band. Ventral third of flanks with a longitudinal series of six to eight cream spots or vertical barshaped marks. Pectoral and pelvic fin rays with brownish gray spots arranged in two or three bands. Dorsal-, anal- and caudal-fin rays brownish gray, with hyaline interradial membranes. Coloration of juveniles (smaller than ca. 30 mm SL) similar, except for being more brown than gray dorsally, a cream belly with brown spotting on posterior half (vs. spotting almost indistinct in adults), and dorsal-, anal- and caudal-fin rays with brown spots arranged into one or two bands (coalescing to give solidly-colored fin rays in adults).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
06D5EEECFADF9110E6A10A63AF29C033.taxon	distribution	Distribution. Known from the Nye River (a tributary of the Ntem River) in northern Gabon (Fig. 7).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
06D5EEECFADF9110E6A10A63AF29C033.taxon	biology_ecology	Habitat. The type locality was a fast-flowing creek over a rock / pebble substrate. The water was cool (22 ° C), acidic (pH 5.0) and tannin-stained. Syntopic fish included: Mormyridae: Brienomyrus sp.; Distichodontidae: Distichodus sp.; Cyprinidae: Barbus spp.; Amphiliidae: Amphilius longirostris; Clariidae: Clarias jaensis; Mochokidae: Chiloglanis cameronensis; Mastacembelidae: Aethiomastacembelus sp.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
06D5EEECFADF9110E6A10A63AF29C033.taxon	etymology	Etymology. From the Latin hirsutus, meaning hairy; in reference to the long tubercles on the dorsal and lateral surfaces of the head, which gives the species a somewhat hairy appearance of the head. Used as an adjective.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
93BA23E88B67ACC38F25BB97EFA41339.taxon	description	(Fig. 11)	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
93BA23E88B67ACC38F25BB97EFA41339.taxon	diagnosis	Diagnosis. Microsynodontis laevigatus can be distinguished from all congeners (except for M. lamberti) in having a smooth (vs. serrated) anterior edge of the pectoral spine (Fig. 4), and a truncate (vs. emarginate or rounded) caudal fin (Fig. 9). It differs from M. lamberti (n = 4) in having a longer adipose fin (33.3 - 35.5 % SL vs. 25.4 - 31.4).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
93BA23E88B67ACC38F25BB97EFA41339.taxon	description	Description. Biometric and meristic data as in Table 5. Body compressed. Predorsal profile steep; postdorsal body sloping gently ventrally. Preanal profile horizontal. Anus and urogenital openings located at vertical through middle of pelvic fin. Skin smooth. Lateral line complete and midlateral. Head depressed and broad, broadly rounded when viewed laterally and with rounded snout margin when viewed from above. Gill openings narrow, extending from immediately ventral to posttemporal to immediately ventral to base of pectoral spine. Gill membranes united to, and attached across, isthmus. Bony elements of dorsal surface of head covered with thin skin. Nuchal shield large and terminating posteriorly with two rounded processes on each side. Supracleithral process thin, extending just short of vertical through posteriormost tip of nuchal shield. Barbels in three pairs. Maxillary barbel long and slender, extending to just beyond base of last pectoral-fin ray. Inner mandibular-barbel origin close to midline, extending to base of pectoral spine and with 2 short, thin branches on anterior half and 3 - 4 long, thin branches on posterior half. Outer mandibular barbel originates posterolateral of inner mandibular barbel, extending to middle of pectoral-fin base and with 3 - 4 long, thin branches. Eye ovoid, horizontal axis longest; located entirely in dorsal half of head. Orbit without free margin. Mouth inferior and crescent-shaped; lips plicate. Oral teeth in rows on all tooth-bearing surfaces. Premaxillae narrow, with narrow ventral shelf and partially exposed when mouth closed. Primary teeth 10 - 14, conical and separated from secondary teeth by distinct gap. Secondary teeth 30 - 40, acutely pointed and recurved; disposed in 3 - 4 rows. Tertiary teeth 18 - 21, elongate, villiform and extending over full width of premaxillae. Dentary teeth 12 - 20, acutely pointed, strongly recurved and broader than secondary teeth; disposed in one or two transverse bands. Dorsal fin located at anterior third of body, with II, 4, i (1); II, 5, i (9) or II, 6 * (4) rays and convex margin. Dorsal-fin spine short, stout and slightly curved; smooth on both anterior and posterior margins. Adipose fin moderately long; margin slightly convex for entire length and posterior end deeply incised. Caudal fin truncate, with i, 6,5, i (14) principal rays. Procurrent rays symmetrical and extend only slightly anterior to fin base. Analfin base located ventral to posterior half of adipose fin. Anal fin with iv, 6 (1) or iv, 7 * (13) rays and convex margin. Pelvic-fin origin at vertical ventral to posterior end of dorsal-fin base. Pelvic fin with i, 6 (14) rays and slightly convex margin; tip of appressed fin not reaching anal-fin origin. Pectoral fin with I, 5, i (14) rays; spine slightly curved and stout (Fig. 4 d). Anterior spine margin smooth along entire length of spine. Posterior spine margin with 7 - 8 strong serrations along entire length. Pectoral-fin margin convex posteriorly. Vertebrae 11 + 22 (2); 11 + 23 (1); 12 + 22 (6); 12 + 23 (3) or 13 + 22 * (2). Males with numerous tubercles on sides of head on region extending from snout to preopercle, and long genital papilla situated immediately posterior to anus. Females with fewer tubercles on sides of head, and with smaller, distally flattened genital papilla. Coloration. In 70 % ethanol: dorsal and lateral surfaces and of head and body medium brown, fading to cream on belly and ventral surfaces (Fig. 11). Medium-sized brown spots evenly scattered over ventral surfaces. Snout with a series of cream spots delineating anterior and posterior nares, sometimes coalescing to form cream band running from anterior orbital margin to tip of snout. Cheek region with numerous small cream spots ventral and posterior to orbit. Cream band encircling nape at supraoccipital. Dorsal third of body with series of four cream irregular blotches extending short of lateral midline of body: first at middle of dorsal-fin base, second at adipose-fin origin, third at middle of adipose-fin base and last on caudal peduncle immediately posterior to adipose fin, sometimes coalescing with similar marks ventrally and encircling caudal peduncle as irregular cream band. Ventral third of flanks with a series of irregular cream blotches sometimes coalescent with dorsal markings to form reticulate pattern. Dorsal, pectoral, pelvic and anal fins hyaline and sometimes with one to two rows of faint spots forming longitudinal brown rows. Caudal fin hyaline, with elongate brown spots forming two to three irregular columns.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
93BA23E88B67ACC38F25BB97EFA41339.taxon	distribution	Distribution. Known only from the Ivindo River in northern Gabon (Fig. 5).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
93BA23E88B67ACC38F25BB97EFA41339.taxon	biology_ecology	Habitat. The type locality is a small, shallow blackwater creek draining into the Ivindo River. The water was extremely low and the substrate was sand with leaf litter, with the area having undergone severe human disturbance. The only other fish species found syntopically was Barbus sp. (Cyprinidae).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
93BA23E88B67ACC38F25BB97EFA41339.taxon	etymology	Etymology. From the Latin laevigatus, meaning smooth. In reference to the smooth anterior edge of the pectoral spine. Used as an adjective.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
A04F91ABA60AAA5CB5A7BE2906176692.taxon	description	(Fig. 12)	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
A04F91ABA60AAA5CB5A7BE2906176692.taxon	diagnosis	Diagnosis. Microsynodontis nannoculus can be distinguished from all congeners in having a smaller eye (10.6 - 12.2 % SL vs. 13.1 - 25.7).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
A04F91ABA60AAA5CB5A7BE2906176692.taxon	description	Description. Biometric and meristic data as in Table 6. Body compressed. Predorsal profile gently convex; postdorsal body sloping gently ventrally. Preanal profile horizontal. Anus and urogenital openings located at vertical through middle of pelvic fin. Skin smooth. Lateral line complete and midlateral. Head depressed and broad, acutely rounded when viewed laterally and with rounded snout margin when viewed from above. Gill openings narrow, extending from immediately ventral to posttemporal to immediately ventral to base of pectoral spine. Gill membranes united to, and attached across, isthmus. Bony elements of dorsal surface of head covered with thin skin. Nuchal shield large and terminating posteriorly with two rounded processes on each side. Supracleithral process thin, extending just short of vertical through posteriormost tip of nuchal shield. Barbels in three pairs. Maxillary barbel long and slender, extending to just beyond base of last pectoral-fin ray. Inner mandibular-barbel origin close to midline, extending to base of pectoral spine and with 2 short, thin branches on anterior half and 3 - 4 long, thin branches on posterior half. Outer mandibular barbel originates posterolateral of inner mandibular barbel, extending to middle of pectoral-fin base and with 3 - 4 long, thin branches. Eye small and ovoid, horizontal axis longest; located entirely in dorsal half of head. Orbit without free margin. Mouth inferior and crescent-shaped; lips plicate. Oral teeth in rows on all tooth-bearing surfaces. Premaxillae narrow, with narrow ventral shelf and partially exposed when mouth closed. Primary teeth 14 - 20, conical and separated from secondary teeth by distinct gap. Secondary teeth 35 - 40, acutely pointed and recurved; disposed in 3 - 4 rows. Tertiary teeth 17 - 23, elongate, villiform and extending over full width of premaxillae. Dentary teeth 18 - 19, acutely pointed, strongly recurved and broader than secondary teeth; disposed in one or two transverse bands. Dorsal fin located at anterior third of body, with II, 7 (2) rays and convex margin. Dorsal-fin spine short, stout and slightly curved; smooth on both anterior and posterior margins. Adipose fin moderately long; margin slightly convex for entire length and posterior end deeply incised. Caudal fin rounded, with principal rays. Procurrent rays symmetrical and extend only slightly anterior to fin base. Anal-fin base located ventral to posterior half of adipose fin. Anal fin with iv, 7 (1) or iv, 9 * (1) rays and convex margin. Pelvic-fin origin at vertical ventral to posterior end of dorsal-fin base. Pelvic fin with i, 6 (2) rays and slightly convex margin; tip of appressed fin not reaching anal-fin origin. Pectoral fin with I, 6 (2) rays; spine slightly curved and stout (as in Fig. 4 f). Anterior spine margin with 17 - 20 small serrations along entire length of spine; serrations antrorse (distally directed) on distal two-thirds and anteriorly directed on proximal third. Posterior spine margin with 9 - 10 strong serrations along entire length. Pectoral-fin margin convex posteriorly. Vertebrae 12 + 24 = 36 * (1) or 13 + 23 = 36 (1). Males with numerous tubercles on sides of head on region extending from snout to preopercle, and long genital papilla situated immediately posterior to anus. Females with fewer tubercles on sides of head, and with smaller, distally flattened genital papilla. Coloration. In 70 % ethanol: dorsal and lateral surfaces and of head and body medium brown, fading to cream or light grayish brown on ventral third of body, belly (with large faint brown spots), and ventral surface of head (Fig. 12). Snout with a series of cream spots delineating anterior and posterior nares, sometimes coalescing to form cream band running from anterior orbital margin to tip of snout. Cheek region with one or two cream spots immediately ventral to orbit. Cream band encircling nape at supraoccipital. Dorsal third of body with series of four cream slender, vertical bar-shaped marks extending beyond lateral midline of body: first at middle of dorsal-fin base, second at adipose-fin origin, third at middle of adipose-fin base and last on caudal peduncle immediately posterior to adipose fin, sometimes encircling caudal peduncle as cream band. Ventral third of flanks with a longitudinal series of five to seven cream spots or vertical bar-shaped marks. Dorsal, pectoral, pelvic and anal fins hyaline and with one to two rows of elongate spots forming longitudinal brown rows. Caudal fin hyaline, with elongate brown spots forming two to three irregular columns.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
A04F91ABA60AAA5CB5A7BE2906176692.taxon	distribution	Distribution. Known only from the Kye River drainage (the Kye River itself is a tributary of the Ntem River) in eastern Equatorial Guinea (Fig. 13). Pappenheim’s (1911) record of M. batesii from the Benito River drainage may belong to this species, but I was unable to examine the specimens to verify their identity.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
A04F91ABA60AAA5CB5A7BE2906176692.taxon	etymology	Etymology. From the Latin nanus, meaning small, and oculus, meaning eye. In allusion to the relatively small eye. Used as a noun in apposition.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
4FB0613EF2084BC79A332F5871B02837.taxon	description	(Fig. 14)	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
4FB0613EF2084BC79A332F5871B02837.taxon	diagnosis	Diagnosis. Microsynodontis nasutus can be distinguished from all congeners in having a longer snout (50.0 - 53.3 % HL vs. 35.7 - 50.0).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
4FB0613EF2084BC79A332F5871B02837.taxon	description	Description. Biometric and meristic data as in Table 7. Body compressed. Predorsal profile gently convex; postdorsal body sloping gently ventrally. Preanal profile horizontal. Anus and urogenital openings located at vertical through middle of pelvic fin. Skin smooth. Lateral line complete and midlateral. Head depressed and broad, broadly rounded when viewed laterally and with rounded snout margin when viewed from above. Gill openings narrow, extending from immediately ventral to posttemporal to immediately ventral to base of pectoral spine. Gill membranes united to, and attached across, isthmus. Bony elements of dorsal surface of head covered with thin skin. Nuchal shield large and terminating posteriorly with two rounded processes on each side. Supracleithral process thin, extending just short of vertical through posteriormost tip of nuchal shield. Barbels in three pairs. Maxillary barbel long and slender, extending to just beyond base of last pectoral-fin ray. Inner mandibular-barbel origin close to midline, extending to base of pectoral spine and with 2 short, thin branches on anterior half and 3 - 5 long, thin branches on posterior half. Outer mandibular barbel originates posterolateral of inner mandibular barbel, extending to middle of pectoral-fin base and with 3 - 5 long, thin branches. Eye ovoid, horizontal axis longest; located entirely in dorsal half of head. Orbit without free margin. Mouth inferior and crescent-shaped; lips plicate. Oral teeth in rows on all tooth-bearing surfaces. Premaxillae narrow, with narrow ventral shelf and partially exposed when mouth closed. Primary teeth 11 - 12, conical and separated from secondary teeth by distinct gap. Secondary teeth 35 - 50, acutely pointed and recurved; disposed in 3 - 4 rows. Tertiary teeth 16 - 20, elongate, villiform and extending over full width of premaxillae. Dentary teeth 14 - 18, acutely pointed, strongly recurved and broader than secondary teeth; disposed in one or two transverse bands. Dorsal fin located at anterior third of body, with II, 6, i * (6) or II, 7 (2) rays and convex margin. Dorsal-fin spine long, stout and slightly curved; smooth on both anterior and posterior margins. Adipose fin moderately long; margin slightly convex for entire length and posterior end deeply incised. Caudal fin rounded, with i, 5,6, i (1); i, 6,5, i (2) or i, 6,6, i * (5) principal rays. Procurrent rays symmetrical and extend only slightly anterior to fin base. Anal-fin base located ventral to posterior half of adipose fin. Anal fin with iv, 6 * (2) or v, 6 (6) rays and convex margin. Pelvic-fin origin at vertical ventral to posterior end of dorsalfin base. Pelvic fin with i, 6 (8) rays and slightly convex margin; tip of appressed fin not reaching anal-fin origin. Pectoral fin with I, 6 (8) rays; spine slightly curved and stout (as in Fig. 4 f). Anterior spine margin with 16 - 22 small serrations along entire length of spine; serrations antrorse (distally directed) on distal two thirds and anteriorly directed on proximal third. Posterior spine margin with 7 - 9 strong serrations along entire length. Pectoralfin margin convex posteriorly. Vertebrae 11 + 25 = 36 (1) or 12 + 24 = 36 * (7). Males with numerous tubercles on sides of head on region extending from snout to preopercle, and long genital papilla situated immediately posterior to anus. Females with fewer tubercles on sides of head, and with smaller, distally flattened genital papilla. Coloration. In 70 % ethanol: dorsal and lateral surfaces and of head and body medium brown, fading to cream or light grayish brown on ventral third of body, belly (with large faint brown spots), and ventral surface of head (Fig. 14). Snout with a series of cream spots delineating anterior and posterior nares, sometimes coalescing to form cream band running from anterior orbital margin to tip of snout. Cheek region with one or two cream spots immediately ventral to orbit. Cream band encircling nape at supraoccipital. Dorsal third of body with series of four cream vertical bar-shaped marks extending beyond lateral midline of body: first at middle of dorsal-fin base, second at adipose-fin origin, third at middle of adipose-fin base and last on caudal peduncle immediately posterior to adipose fin, sometimes encircling caudal peduncle as cream band. Ventral third of flanks with a longitudinal series of five to seven cream spots or vertical bar-shaped marks. Dorsal, pectoral, pelvic and anal fins hyaline and sometimes with one to two rows of faint spots forming longitudinal brown rows. Caudal fin with similar series of elongate marks forming two to three irregular columns.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
4FB0613EF2084BC79A332F5871B02837.taxon	distribution	Distribution. Known from the Okano River, a tributary of the Ogooue River, in northern Gabon (Fig. 13).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
4FB0613EF2084BC79A332F5871B02837.taxon	biology_ecology	Habitat. The type locality was a whitewater river, with the following fish found syntopically: Mormyridae: Brienomyrus spp.; Distichodontidae: Distichodus hypostomatus; Cyprinidae: Barbus martorelli, Labeo spp., Opsaridium ubangense; Amphiliidae: Amphilius longirostris, Amphilius nigricaudatus, Doumea typica, Phractura sp.; Claroteidae: Anaspidoglanis macrostoma; Mochokidae: Atopochilus savorgnani; Cichlidae: Hemichromis fasciatus; Mastacembelidae: Caecomastacembelus niger.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
4FB0613EF2084BC79A332F5871B02837.taxon	etymology	Etymology. From the Latin nasutus, meaning large nosed; in reference to the long snout of this species. Used as a noun in apposition.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
A43D3DA21870297F5F73C797E395089E.taxon	description	(Fig. 15)	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
A43D3DA21870297F5F73C797E395089E.taxon	diagnosis	Diagnosis. Microsynodontis notatus can be distinguished from all congeners except for M. christyi and M. laevigatus in having a deeper caudal peduncle (9.6 - 11.9 % SL vs. 5.8 - 9.8). It differs firom M. christyi in having a larger eye (17.2 - 25.7 % HL vs. 13.6 - 17.9) and from M. laevigatus in having a serrated (vs. smooth) anterior edge of the pectoral spine (Fig. 4) and a rounded (vs. truncate) caudal fin (Fig. 9). It also differs from all congeners in frequently having numerous faint, dark brown elongate spots on the body (vs. spots always absent).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
A43D3DA21870297F5F73C797E395089E.taxon	description	Description. Biometric and meristic data as in Table 8. Body compressed. Predorsal profile steep; postdorsal body sloping gently ventrally. Preanal profile horizontal. Anus and urogenital openings located at vertical through middle of pelvic fin. Skin smooth. Lateral line complete and midlateral. Head depressed and broad, broadly rounded when viewed laterally and with rounded snout margin when viewed from above. Gill openings narrow, extending from immediately ventral to posttemporal to immediately ventral to base of pectoral spine. Gill membranes united to, and attached across, isthmus. Bony elements of dorsal surface of head covered with thin skin. Nuchal shield large and terminating posteriorly with two rounded processes on each side. Supracleithral process thin, extending just short of vertical through posteriormost tip of nuchal shield. Barbels in three pairs. Maxillary barbel long and slender, extending to just beyond base of last pectoral-fin ray. Inner mandibular-barbel origin close to midline, extending to base of pectoral spine and with 2 short, thin branches on anterior half and 3 - 4 long, thin branches on posterior half. Outer mandibular barbel originates posterolateral of inner mandibular barbel, extending to middle of pectoral-fin base and with 3 - 4 long, thin branches. Eye large and ovoid, horizontal axis longest; located entirely in dorsal half of head. Orbit without free margin. Mouth inferior and crescent-shaped; lips plicate. Oral teeth in rows on all tooth-bearing surfaces. Premaxillae narrow, with narrow ventral shelf and partially exposed when mouth closed. Primary teeth 11 - 14, conical and separated from secondary teeth by distinct gap. Secondary teeth 30 - 40, acutely pointed and recurved; disposed in 3 - 4 rows. Tertiary teeth 16 - 20, elongate, villiform and extending over full width of premaxillae. Dentary teeth 15 - 19, acutely pointed, strongly recurved and broader than secondary teeth; disposed in one or two transverse bands. Dorsal fin located at anterior third of body, with II, 6 * (14) or II, 7 (20) rays and convex margin. Dorsal-fin spine long, stout and slightly curved; smooth on both anterior and posterior margins. Adipose fin moderately long; margin slightly convex for entire length and posterior end deeply incised. Caudal fin rounded, with i, 5,6, i (1) or i, 6,6, i * (33) principal rays. Procurrent rays symmetrical and extend only slightly anterior to fin base. Anal-fin base located ventral to posterior half of adipose fin. Anal fin with iii, 7 (1); iii, 8 (4); iv, 7 * (11) or iv, 8 (18) rays and convex margin. Pelvic-fin origin at vertical ventral to posterior end of dorsal-fin base. Pelvic fin with i, 6 (34) rays and slightly convex margin; tip of appressed fin not reaching anal-fin origin. Pectoral fin with I, 6 * (32) or I, 6, i (2) rays; spine slightly curved and stout (Fig. 4 e). Anterior spine margin with 3 - 16 small serrations along entire length of spine; serrations antrorse (distally directed) on distal two-thirds and anteriorly directed on proximal third. Posterior spine margin with 6 - 12 strong serrations along entire length. Pectoral-fin margin convex posteriorly. Vertebrae 12 + 23 (2); 12 + 24 (6); 13 + 22 (1); 13 + 23 * (10); 13 + 24 (12) or 14 + 23 (3). Males with numerous tubercles on sides of head on region extending from snout to preopercle, and long genital papilla situated immediately posterior to anus. Females with fewer tubercles on sides of head, and with smaller, distally flattened genital papilla. Coloration. In 70 % ethanol: dorsal and lateral surfaces and of head and body light to medium brown, fading to cream on belly and ventral surfaces (Fig. 15). Dorsal and lateral surfaces of head and body frequently with dark brown elongate spots evenly distributed and forming a reticulate pattern. Snout with a series of cream spots delineating anterior and posterior nares. Cheek region with one or two cream spots immediately ventral to orbit. Cream band encircling nape at supraoccipital. Dorsal third of body with series of five cream vertical bar-shaped marks extending to lateral midline of body: first at middle of dorsal-fin base, second at adipose-fin origin, third at middle of adipose-fin base, fourth at posteriormost point of adipose-fin base and last on caudal peduncle immediately posterior to adipose fin, sometimes encircling caudal peduncle as cream band. Ventral third of flanks with a longitudinal series of four to seven cream spots or vertical bar-shaped marks. Adipose fin brown, with an extensive hyaline margin and sometimes with dark brown spots and vermiform marks. Dorsal, pectoral, pelvic and anal fins hyaline and with one to two rows of elongate spots forming longitudinal brown rows. Caudal fin hyaline, with elongate brown spots forming two to three irregular columns.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
A43D3DA21870297F5F73C797E395089E.taxon	distribution	Distribution. Known only from the lower Ogooue River in Gabon (Fig. 5).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
A43D3DA21870297F5F73C797E395089E.taxon	etymology	Etymology. From the Latin notatus, meaning marked. In reference to the dark elongate spots frequently present in this species. Used as an adjective.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
B971FD788D4AA907DD0572C78F5CD86E.taxon	description	(Fig. 16)	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
B971FD788D4AA907DD0572C78F5CD86E.taxon	diagnosis	Diagnosis. Microsynodontis vigilis can be distinguished from all congeners in having a longer supracleithral process (reaching to vertical through the posteriormost tip of nuchal shield vs. not reaching). It further differs from all other congeners except for M. armatus and M. lamberti in having a shorter adipose fin (22.0 - 28.2 % SL vs. 27.9 - 41.6), and except for M. emarginatus, M. lamberti, and M. notatus, in having a larger eye (19.3 - 25.0 % HL vs. 10.6 - 19.6). Microsynodontis vigilis can be further distinguished from M. lamberti in having a serrated (vs. smooth) anterior edge of the pectoral spine and a round (vs. truncate) caudal fin.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
B971FD788D4AA907DD0572C78F5CD86E.taxon	description	Description. Biometric and meristic data as in Table 9. Body compressed. Predorsal profile gently convex; postdorsal body sloping gently ventrally. Preanal profile horizontal. Anus and urogenital openings located at vertical through middle of pelvic fin. Skin smooth. Lateral line complete and midlateral. Head depressed and broad, acutely rounded when viewed laterally and with rounded snout margin when viewed from above. Gill openings narrow, extending from immediately ventral to posttemporal to immediately ventral to base of pectoral spine. Gill membranes united to, and attached across, isthmus. Bony elements of dorsal surface of head covered with thin skin. Nuchal shield large and terminating posteriorly with two rounded processes on each side. Supracleithral process thin, extending to vertical through posteriormost tip of nuchal shield. Barbels in three pairs. Maxillary barbel long and slender, extending to just beyond base of last pectoral-fin ray. Inner mandibular-barbel origin close to midline, extending to base of pectoral spine and with 2 short, thin branches on anterior half and 3 - 5 long, thin branches on posterior half. Outer mandibular barbel originates posterolateral of inner mandibular barbel, extending to middle of pectoral-fin base and with 3 - 5 long, thin branches. Eye large and ovoid, horizontal axis longest; located entirely in dorsal half of head. Orbit without free margin. Mouth inferior and crescent-shaped; lips plicate. Oral teeth in rows on all tooth-bearing surfaces. Premaxillae narrow, with narrow ventral shelf and partially exposed when mouth closed. Primary teeth 13 - 14, conical and separated from secondary teeth by distinct gap. Secondary teeth 40 - 85, acutely pointed and recurved; disposed in 3 - 4 rows. Tertiary teeth 22 - 26, elongate, villiform and extending over full width of premaxillae. Dentary teeth 17 - 27, acutely pointed, strongly recurved and broader than secondary teeth; disposed in one or two transverse bands. Dorsal fin located at anterior third of body, with II, 6 (1) or II, 7 * (17) rays and convex margin. Dorsal-fin spine long, stout and slightly curved; smooth on both anterior and posterior margins. Adipose fin moderately long; margin slightly convex for entire length and posterior end deeply incised. Caudal fin rounded, with i, 6,6, i (18) principal rays. Procurrent rays symmetrical and extend only slightly anterior to fin base. Anal-fin base located ventral to posterior half of adipose fin. Anal fin with iii, 7 (2); iii, 8 * (3); iv, 7 (10) or iv, 8 (3) rays and convex margin. Pelvic-fin origin at vertical ventral to posterior end of dorsalfin base. Pelvic fin with i, 6 (18) rays and slightly convex margin; tip of appressed fin not reaching anal-fin origin. Pectoral fin with I, 5 (2); I, 6 (14) or I, 6, i * (2) rays; spine slightly curved and stout (as in Fig. 4 f). Anterior spine margin with 22 - 28 small serrations along entire length of spine; serrations antrorse (distally directed) on distal two-thirds and anteriorly directed on proximal third. Posterior spine margin with 8 - 13 strong serrations along entire length. Pectoral-fin margin convex posteriorly. Vertebrae 11 + 24 (1); 13 + 23 (7); 13 + 24 * (6); 14 + 22 (1) or 14 + 23 (3). Males with numerous tubercles on sides of head on region extending from snout to preopercle, and long genital papilla situated immediately posterior to anus. Females with fewer tubercles on sides of head, and with smaller, distally flattened genital papilla. Coloration. In 70 % ethanol: dorsal and lateral surfaces and of head and body dark chocolate brown, fading to light brown on belly (Fig. 16). Snout with a series of light yellow spots delineating anterior and posterior nares. Cheek region with one or two light yellow spots immediately ventral to orbit. Light yellow band encircling nape at supraoccipital. Dorsal third of body with series of four light yellow vertical bar-shaped marks extending to lateral midline of body: first at middle of dorsal-fin base, second at adipose-fin origin, third at middle of adipose-fin base and last on caudal peduncle immediately posterior to adipose fin, sometimes encircling caudal peduncle as light yellow band. Ventral third of flanks with a longitudinal series of four to seven light yellow spots or vertical bar-shaped marks. Dorsal fin with dark chocolate brown base and one to two rows of elongate spots forming longitudinal dark chocolate brown rows. Pectoral, pelvic and anal fins with hyaline bases and similarly marked. Caudal fin hyaline, with elongate brown spots forming two to three irregular columns.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
B971FD788D4AA907DD0572C78F5CD86E.taxon	distribution	Distribution. Known only from the lower Ogooue River drainage in Gabon (Fig. 13).	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
B971FD788D4AA907DD0572C78F5CD86E.taxon	biology_ecology	Habitat. The type locality is a forest stream with a sandy bottom. Water temperature was 24.4 ° C and the pH was 5.5. Syntopic fish included: Mormyridae: Brienomyrus sp., Mormyrops zanclirostris, Stomatorhinus spp.; Characidae: Alestes sp., Brycinus sp.; Ditichodontidae: Nannocharax sp.; Cyprinidae: Barbus spp.; Amphiliidae: Amphilius nigricaudatus, Phractura sp.; Claroteidae: Anaspidoglanis macrostoma; Malapteruridae: Malapterurus beninensis; Mochokidae: Synodontis sp.; Cyprinodontidae: Epiplatys dageti, Plataplochilus chalcopyrus; Channidae: Parachanna obscura; Cichlidae: Hemichromis sp.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
B971FD788D4AA907DD0572C78F5CD86E.taxon	etymology	Etymology. From the Latin vigilis, meaning watchful. In allusion to the relatively large eyes of this species. Used as an adjective.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
F7AEE3576C26FA0BC32EDF78CEAF803B.taxon	discussion	Discussion The identification of Microsynodontis species is often difficult, primarily because of the large amounts of purported variation observed in biometrics and color (Poll & Gosse, 1963; Matthes, 1964); one outcome of this observation was the synonymy of M. christyi with M. batesii by Matthes (1964). These conclusions were drawn without the examination of large series from a single locality (or at least multiple closely situated localities within the same drainage), and the high degree of variation reported is due to confusion between intraspecific and interspecific differences. However, after examining a large series of M. batesii in this study, the limits of intraspecific variation within Microsynodontis can be better understood, and M. christyi is found to be a valid species distinguished from M. batesii by coloration and other morphological characters (see below). Examination of large series of specimens (identifiable as M. batesii) from within several closely situated localities within the Ntem River drainage in northern Gabon and southern Cameroon leads me to conclude that although intraspecific variation in color (and certainly in biometrics) exists, color patterns are useful diagnostic characters once the degree of intraspecific variation is understood. Furthermore, diagnostic characters not previously identified, some of which have been used in other mochokid genera, were found to be useful for distinguishing species of Microsynodontis. These characters consist of the snout, fin spine (both dorsal and pectoral) and tubercle morphology, all of which have been previously used to diagnose species in other mochokid genera, but not in Microsynodontis. Although a combination of these characters is the easiest way to distinguish among the Microsynodontis of the lower Guinea region, some biometric characters can also be used to diagnose the species (diagnostic biometric characters for the other species of Microsynodontis not found in the lower Guinea region are given in Table 10). However, the numbers of oral teeth, a character considered diagnostic in other mochokid genera, are not useful in diagnosing species of Microsynodontis, as they are apparently highly conservative in the genus. The variation in color is largely of an ontogenetic nature, and its use as a more reliable diagnostic character is possible once the limits of variation are understood. The ontogenetic change in color pattern is most marked for M. batesii, and consists of changes in both the pigmentation pattern of the abdomen and the shape of the light-colored markings on the body. In the former case, many juvenile specimens have a dense aggregation of melanophores concentrated in a series of evenly distributed large spots on the abdomen that fade with age (Fig. 1 c), and in the latter case, the dorsal and ventral light-colored markings may coalesce to form complete bands encircling the body, especially in the region of the caudal peduncle (Fig. 1 c). The light-colored markings on the ventral third of the body in juvenile specimens are also more vermiform (Fig. 1 c). In any case, M. batesii (and all other species from the lower Guinea region) of all sizes always possess a light-colored band encircling the nape, which is absent in M. christyi of all sizes examined, even in preserved material. Therefore, the absence of this band is a useful diagnostic character for distinguishing M. christyi from M. batesii (and all other species of Microsynodontis from the lower Guinea region). Microsynodontis christyi can also be distinguished from M. batesii in having a deeper caudal peduncle (10.0 - 11.8 % SL vs. 5.8 - 9.2). The distributions of the two species also suggest that they are different: M. christyi is only known from the middle Congo River drainage while M. batesii is only known from the lower Guinea region (in the Campo, Ivindo, Ntem, Nyong and Sanaga River drainages). Very little material of Microsynodontis from the middle Congo River drainage was available for study, but the examination of all material available suggests that there are no species in common between the middle Congo River drainage and those of the lower Guinea region. This is so even when the tributaries of the Congo and the smaller coastal drainages of the lower Guinea region are immediately adjacent, as in the case of the material identified as M. batesii from the Dja River (a tributary of the Congo River flowing approximately southwest in southern Cameroon and located adjacent to the Ntem River drainage), which is not conspecific with M. batesii and represents a distinct, undescribed species. This study reveals the importance of some biometric measurements as diagnostic characters. In particular, two of the species described here, M. nannoculus and M. nasutus, are distinguished from congeners chiefly by biometric measurements. Bivariate analyses (ANCOVA) of the regression lines of eye diameter (Fig. 17), snout length (Fig. 18), caudal peduncle depth (Fig. 19), adipose basal length (Fig. 20) and caudal-fin length (Fig. 21) on SL are significantly different (given the number of taxa used in the analysis, it was not possible to display all of them on the biplots without obscuring key patterns and only the key taxa for each biometric value are used in Figs. 17 - 21). The P values of the analyses are given in Table 11, and it can be seen that regression lines are all significantly different for the eye diameter of M. nannoculus and for the snout length of M. nasutus, when both are compared to the corresponding data for all congeners. Sexual dimorphism in Microsynodontis is reported for the first time in this study. Males of Microsynodontis species can be distinguished from females by the presence of a conical genital papilla immediately posterior to the anus (females have a smaller papilla that is distally flattened) and (especially in mature adults of all lower Guinea species except for M. emarginatus) by a much denser aggregation of tubercles on the dorsal and lateral surfaces of the head, especially in the region on the sides of the head from the snout to the preopercle. The presence of tubercles has been used as a diagnostic character in the Mochokidae, e. g. in Synodontis (see Boulenger, 1900) and Chiloglanis (see Roberts, 1989), but has not been previously used for Microsynodontis. The results of this study indicate that tubercle shape is useful in diagnosing at least one species, M. hirsutus, from its congeners. Although the number and density of tubercles differ both sexually and ontogenetically, the tubercles retain their characteristic shape in specimens of both sexes and all sizes in M. hirsutus, making it a useful diagnostic character for this species. Despite the fact that Microsynodontis species are occasionally imported for the aquarium trade and are not considered rare, very little is known of their biology, from either field or aquarium observations. This is probably because these fishes, like many other small fishes in ichthyological expeditions, are often overlooked and are thus not particularly well represented in collections. With the number of species identified in this study, it is clear that this element of the ichthyofauna (the miniature species) is in need of further study.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
BF49DC4D147B86C4E1D468A1A9385C9C.taxon	materials_examined	BMNH 1919.9.10.281, syntype, 39.8 mm SL; Congo Democratic Republic: Poko. MRAC 61788 - 61801, 14 ex., 17.8 - 37.5 mm SL; Congo Democratic Republic: Buta.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
2AFBA83C3095530479EDE6247CDEC30D.taxon	materials_examined	MRAC 137840 - 41, 2 paratypes, 22.8 - 26.0 mm SL; MRAC 37842 - 43, 2 paratypes, 29.5 - 29.6 mm SL; Congo Democratic Republic: Lilanda River at Yangole.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
56A16462F50EB2A1BE51CC7D76F2D850.taxon	materials_examined	MRAC 119547, holotype, 32.0 mm SL; Guinea: Gbin River (photograph examined). MRAC 172458 - 172460 (3), 25.0 - 27.0 mm SL; Congo Democratic Republic: Kinshasa, Stanley Pool. MRAC 88 - 01 - P- 2122 (1), 35.1 mm SL; Congo Democratic Republic: Kinshasa, rapids at the exit of Stanley Pool. MRAC 88 - 01 - P- 2126 - 2128 (3), 26.0 - 37.8 mm SL; Congo Democratic Republic: Large island of Djili, Congo-Ubangi drainage. MRAC 88 - 01 - P- 2171 (1), 25.7 mm SL; Congo Democratic Republic: mouth of Nutile River. MRAC 99 - 078 - P- 0017 (1), 43.8 mm SL; Congo Democratic Republic: Kwango.	en	Heok Hee Ng (2004): The Microsynodontis (Teleostei: Siluriformes: Mochokidae) of the lower Guinea region, west central Africa, with the description of eight new species. Zootaxa 531: 1-52, URL: http://www.zoobank.org/urn:lsid:zoobank.org:pub:C2558C86-B7AE-4D51-8B44-0BB2828F100C
