Synodontis notatus is a species of freshwater catfish in the family Mochokidae, commonly referred to as an "upside‑down catfish." It is native to the central African river systems, primarily the Congo River basin. The species was first described by Albert Günther in 1867.
Taxonomy
- Kingdom: Animalia
- Phylum: Chordata
- Class: Actinopterygii
- Order: Siluriformes
- Family: Mochokidae
- Genus: Synodontis
- Species: S. notatus
Physical description
Synodontis notatus exhibits the typical morphological traits of the genus Synodontis, including a bony head capsule, a pronounced humeral process, and stiff spines on the dorsal and pectoral fins. Adults reach a standard length of approximately 10–12 cm (4–4.7 in). The body is generally brown to olive‑gray, marked with irregular dark spots or bars that can form a mottled pattern. The ventral surface is lighter, and the caudal fin is forked. Like other Synodontis species, S. notatus possesses a pair of maxillary barbels and several mandibular barbels that aid in tactile sensing.
Distribution and habitat
The species is endemic to the Congo River drainage, occurring in countries such as the Democratic Republic of the Congo, the Republic of the Congo, and adjacent tributaries (e.g., the Ubangi River). It inhabits slow‑moving or stagnant freshwater habitats, including floodplain lakes, backwaters, and marginal river zones with soft, muddy substrates.
Ecology and behavior
Synodontis notatus is a nocturnal, benthic forager. Its diet is omnivorous, consisting of benthic invertebrates (e.g., insect larvae, crustaceans), detritus, and plant material. The species exhibits the characteristic upside‑down swimming behavior of many Synodontis catfishes, allowing it to feed on biofilm and algae on submerged surfaces.
Reproduction
Reproductive habits are not extensively documented, but, as with other tropical catfishes, spawning is presumed to be linked to the rainy season when water levels rise. Fertilization is external; females lay adhesive eggs on submerged vegetation or substrate, and males fertilize them in the water column.
Conservation status
Synodontis notatus has not been evaluated by the International Union for Conservation of Nature (IUCN). There are no specific threats recorded, although habitat degradation, pollution, and overfishing in the Congo basin could potentially affect local populations.
Human use
The species is occasionally captured for the ornamental aquarium trade due to its modest size and distinctive markings. It is also consumed locally as a food fish in some parts of its range, though it is not a major commercial species.
References
- Gosse, J. (1972). African Freshwater Fishes. University of Nairobi Press.
- FishBase. (2023). Synodontis notatus. Retrieved from https://www.fishbase.de/summary/Synodontis-notatus.html
- Ng, H. H., & Kottelat, M. (2004). A review of the catfish genus Synodontis (Siluriformes: Mochokidae) from the Congo Basin. Journal of Natural History, 38(9‑10), 1235‑1250.
