As the name and picture illustrate, these Catfish actually do spend most of their time swimming upside down. Crazy, huh? Their coloration actually reflects their preferred bodily orientation. Unlike other fish who are dark on the top and paler on the bottom (to beldn with predators who would be looking up or down at them), these guys have pales backs and dark bellies!
Why do they swim like this? For hunting reasons. By looking up at prey they can surprise it easier, catching it quickly from below. They feed on small insects and crustaceans.
Interestingly, the Catfish aren't born swimming upside down-- they don't really invert until they are around 2 months old. Overall they don't get particularly large as they age. 3-4 inches is their maximum size.
Blotched Upside-down Catfish can be kept as pets, and do best in small groups of 3 or 4.
IUCN Status : Least Concern
Location : Congo River Basin
Size : Length up to 4in (12cm)
Classification : Phylum : Chordata -- Class : Actinopterygii -- Order : Siluriformes
Family : Mochokidae -- Genus : Synodontis -- Species : S. nigriventis
Image : SeriouslyFish