Taxonomy & naming
Synodontis resupinatus Boulenger, 1904 is the valid name in the Catalog of Fishes, described from Lokoja in northern Nigeria. The epithet is Latin for 'bent back' or 'lying on the back', in keeping with the upside-down swimming habit of the species.
Morphology
Like other squeakers, it has a broad head, three pairs of barbels (an unbranched maxillary pair and two branched mandibular pairs), an adipose fin and a stout, serrated, lockable spine at the front of the dorsal and each pectoral fin. The skin is scaleless. The spines tangle in nets and can pierce skin, and rubbing the pectoral spine against the girdle makes the audible squeak that gives the group its name. FishBase gives a maximum of 10 in SL, and cites a second source with a maximum of 14 in TL.
Habitat
FishBase gives its range as the Niger basin, including the Benue, and lists it as a freshwater, benthopelagic tropical fish. It occurs in vegetated areas of the lake. The type locality is Lokoja on the Niger, Nigeria.
Feeding
Synodontis are opportunistic omnivores that forage mostly at night, taking insect larvae, small crustaceans, molluscs, detritus and plant material. FishBase calls this species an omnivore that feeds on plankton and detritus. In the aquarium the genus takes sinking pellets, wafers and frozen foods readily, best offered after lights-out.
Mating
FishBase says it is oviparous with distinct pairing during breeding. Where Synodontis have been studied, spawning is a pair or group event in sheltered sites, with eggs left unguarded or only loosely guarded.
Breeding
FishBase lists it as oviparous with distinct pairing. Breeding in aquaria has not been recorded; most Synodontis are not bred routinely by hobbyists, and commercially available fish are generally wild-caught.
In the aquarium
Keep it in a roomy tank with caves, wood or rock stacks to retire to by day, a fine substrate, and tankmates too large to be eaten and robust enough to ignore the spines. Net with a container, not a mesh net, to avoid tangling. Medicate cautiously, as scaleless skin is sensitive. FishBase gives no temperature, pH or hardness range for this species. Because it swims inverted, give it open water and surface space.
Conservation
The IUCN Red List assessed it as Least Concern in 2019, meaning it is not considered at risk of extinction at present. Wild-caught fish enter the trade, but the effect on wild populations has not been described.