Taxonomy & naming
Described by Achille Valenciennes in Cuvier & Valenciennes, 1840, with the type locality at the Senegal River, Senegal. It is a valid species of Synodontis in the Catalog of Fishes. The name has been tangled with similar West African species such as S. schall in older literature, so wild-caught fish sold under this name deserve a careful check against a key.
Morphology
A typical large Synodontis: broad head, three pairs of barbels, a locking serrated dorsal and pectoral spine, and a scaleless dark body. FishBase gives a maximum of 13 in TL, while a measured specimen series is recorded there at 8.5 in TL (6.5 in SL).
Habitat
Native to West African river systems, with the Senegal River as the type locality. Seasonal savanna rivers with variable flow and turbidity are the likely setting. FishBase lists a temperature range of 70–79 °F and a pH of 6.0 to 7.5.
Feeding
Omnivorous bottom feeder, as is usual for the genus: insect larvae, crustaceans, detritus and plant matter taken mostly at night. In the aquarium it accepts sinking pellets, wafers and frozen foods.
Mating
FishBase describes distinct pairing during breeding. Sexual differences in squeakers are usually subtle, with females fuller-bodied when ripe.
Breeding
The species is oviparous, and FishBase notes distinct pairing at spawning. No aquarium breeding record is known to the atlas, and wild-caught imports dominate supply.
In the aquarium
Plan for a large, catfish-sized tank with caves and driftwood, water at about 70–79 °F and pH 6.0 to 7.5, and tankmates too big to be eaten. The locking spines tangle in nets, so move it in a container. Like all Synodontis it is scaleless and sensitive to copper medications.
Conservation
The IUCN Red List assessed Synodontis nigrita as Least Concern in 2019. Wild-caught fish are the usual source in trade.