Synodontis woleuensis Friel & Sullivan, 2008

From Friel & Sullivan, 2008:

Diagnosis.—Synodontis woleuensis can be distinguished from all congeners by the combination of well developed serrations on the anterior margin of the dorsal spine and a distinctive pigmentation pattern. Its unique pigmentation is characterized by: 1) a variable pattern and number of light, cream colored spots—irregular in size and shape, but always smaller than the orbit diameter—distributed over a largely uniform dark brown upper body and over a more lightly pigmented ventral surface, and 2) a narrow, depigmented, curved band along the entire anterior margin of the caudal fin. While the position and number of light spots on the body is variable, one spot always occurs on the dorsum at the origin of the adipose fin and another at the terminus of this fin.
Synodontis woleuensis differs markedly in its pigmentation from the two other species of Synodontis in West Central Africa that possess an anteriorly serrated dorsal spine: S. batesii Boulenger 1907 and S. albolineata Pellegrin 1924. In these species, pigmentation on the ventral surface is as dark or darker than the sides and dorsal surface of the body, not lighter as in S. woleuensis. Synodontis albolineata has a prominent white band overlaying the lateral line and head and flanks are characterized by irregular small dark brown spots and blotches over a lighter brown background. Synodontis batesii in contrast has three broad, irregular dark brown bands along its flanks: the first below the dorsal fin, the second below the adipose fin and the third in advance of the caudal fin and elsewhere irregular dark brown blotches superimposed over a light brown background. Synodontis batesii and S. albolineata have neither the spotted pattern of S. woleuensis, nor the depigmented curved band at the anterior margin of the caudal fin.

Description.—Small species with a maximum standard length <70 mm. Body compressed. Predorsal profile gently convex; postdorsal body sloping gently ventrally. Preanal profile horizontal. Anus and urogenital opening located slightly anterior to vertical though origin of adipose fin. Skin on body smooth without any enlarged tubercles, lateral line complete and midlateral along entire side of body. Head depressed and broad, obtusely pointed when viewed laterally with a slightly pointed margin when viewed dorsally. Gill opening restricted to lateral aspect of head from level of the base of pectoral spine dorsally to level of the ventral margin of the eye. Gill membranes broadly united to, and attached across the isthmus, supported by 6 branchiostegal rays. Bony elements of skull roof with superficial, granular ornamentation. Skin covering skull roof with a few small unculiferous tubercles. Occipital-nuchal shield large, without prominent sutures, terminat- ing posteriorly with two rounded processes on each side of dorsal fin. Barbels in three pairs. Maxillary barbel long, slend- er and unbranched, extending well beyond base of last pectoral-fin ray when intact. No basal membrane present on maxillary barbel. Mandibular barbels originate immed- iately posterior to lower lip in a transverse row. Lateral mandibular barbels long, reaching just beyond pectoral fin insertion, with 5 or 6 primary, unpaired, simple branches. Medial mandibular barbels, somewhat less than 2/3rds the length of the lateral barbels, with 3 or 4 paired proximal branches with secondary ramifications, and 2 or 3 more distal, unpaired branches.Eyes relatively small, slightly ovoid; horizontal diam- eter approximately half orbital interspace. Orbit with a free margin. Anterior nares slightly closer together than poste- rior nares. Anterior nares tubular with a short raised rim. Posterior nares with elevated flaps along anterior margin.

Mouth inferior and crescent shaped; lips plicate. All teeth unicuspid. Primary, secondary and tertiary premaxil- lary teeth discrete. Primary teeth robust and conical, 25–40. Secondary teeth, shorter and conical, 22–50. Tertiary teeth slender and elongate, 40–65. Mandibular teeth 26–41; concentrated in a clump at jaw symphysis; individual teeth “S” shaped in lateral view and strongly recurved. Dorsal fin located at anterior third of body. Dorsal fin with spinelet, spine and 7 rays; fin membrane not adnate with body. Dorsal-fin spine long and straight; with 14–19 well-developed serrations along proximal 2/3rd of anterior margin; a few weakly developed serrations on distal 1/3rd of posterior margin. Adipose fin well developed; margin convex. Caudal fin forked, count i,7,8,i. Procurrent caudal- fin rays symmetrical and extend only slightly anterior to fin base. Anal-fin base located ventral to adipose fin; margin convex. Anal-fin count usually iii,8. Pelvic-fin origin slight- ly behind vertical from posterior end of dorsal fin base. Pelvic-fin margins convex, tip of appressed fin just reaches anal-fin origin. Pelvic-fin count i,6. Pectoral-fin count I,7. Pectoral fin with straight, stout spine bearing 19–27 large, distally directed serrations on anterior margin and 10–15 large, proximally directed serrations on posterior margin. Cleithral process with a distinct lateral ridge, elongated and narrow with concave dorsal profile and terminating in a sharp point just beyond vertical from terminus of nuchal shield. No obvious axillary pore. No apparent sexual dimorphism in shape or size of fins, body ornamentation, or tuberculation of skin. Dimorphism in body size present: largest specimens in all samples examined are females.

Coloration.—In dorsal and lateral views, specimens appear uniformly medium to dark brown with numerous, small, irregular, light spots. Spots on flanks often bear raised neuromasts near their centers. All specimens with a light spot at both anterior and posterior margins of adipose fin. Commonly specimens also bear a light spot at posterior margin of dorsal fin