Synodontis nigrita Valenciennes, 1840
photo by JJPhoto

Family:  Mochokidae (Squeakers or upside-down catfishes), subfamily: Mochokinae
Max. size:  33.5 cm TL (male/unsexed)
Environment:  benthopelagic; freshwater; pH range: 6 - 7.5; dH range: 4 - 15, potamodromous
Distribution:  Africa: Senegal, Gambia, Casamance, Géba, Volta, Niger (including the Benue) and Chad basins (Ref. 57223). Also in the Sio and Mono in Togo, Lake Nokoué (Ouémé basin) in Benin, Kwa Ibo (Ref. 57223) and Cross in Nigeria (Ref. 57223, 81251) and the Ntem in Cameroon (Ref. 81251). Present in the Nile basin (Ref. 7362, 28714). Reported from the Bohou River (AMNH 228566)(Ubangi River system, middle Congo River basin)(Ref. 41414). Report from the Kolenté (=Great Scarcies)(Ref. 3202, 81251) unconfirmed in Ref. 57223.
Diagnosis:  Dorsal spines (total): 1; Anal spines: -0. Diagnosis: gill slits not extending ventrally beyond pectoral-fin insertions; interorbital space less than 50% of head width (Ref. 57223), 89.3-102.3% snout length (Ref. 81251). Snout large and subrounded; lips moderately developed (Ref. 81251). Post-orbital length at least 60% of snout length; maxillary barbels longer than head, unbranched, without tubercles and bordered by a distinct, black basal membrane (Ref. 57223, 81251) at least as broad as barbel (Ref. 81251). Outer mandibular barbels with few short, spike-like ramifications, branches of inner mandibular barbels globose and bearing 2-3 tubercles; mandibular teeth thin and small, numbering 25-38 (Ref. 57223, 81251), movable, forming a transverse band (Ref. 81251). Entire margin of opercle smooth (Ref. 81251). Denticulations on outer margins of pectoral-fin spines relatively well developed on outer margin, but weaker than those on inner margin (Ref. 57223). Pelvic fin not reaching anal fin (Ref. 81251). Dorsal-fin spine smooth anteriorly, except for a few (4-5) apical denticles (Ref. 57223, 81251), none on posterior edge (Ref. 81251); humeral process triangular, rather deep (Ref. 57223), keeled ventrally (Ref. 57223, 81251) and sharply pointed (Ref. 81251). Adipose fin short (Ref. 57223, 81251), 1.1 to 3.4 times as long as its distance from first dorsal, and deep (base 2.1 to 4.7 times depth) (Ref. 81251), and distinctly separated from rayed dorsal fin (Ref. 57223). Anal fin with elongate anterior rays (Ref. 81251). Body covered with spots of about 1 mm in diameter; caudal fin spotted (Ref. 57223), without a single dark patch at base of each fin lobe (Ref. 81251). Caudal fin deeply forked, with upper lobes slightly longer; caudal peduncle as long as deep (Ref. 81251). Coloration: brownish, somewhat paler on belly; type not well preserved, but still has some black spots on adipose fin, possibly suggesting an also spotted body; other specimens have in fact body and head covered with spots; fins also spotted, the spots on caudal fin aligned as a band; maxillary barbels and their basal membranes black (Ref. 57223, 81251).
Biology:  Maximum TL was recorded at 22.0 cm (Ref. 57223), maximum SL 16.8 (Ref. 81251). Oviparous (Ref. 205).
IUCN Red List Status: Least Concern (LC); Date assessed: 02 June 2019 Ref. (130435)
Threat to humans:  harmless


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