Synodontis longirostris

Like all members of the genus Synodontis, S. longirostris has a strong, bony head capsule that extends back as far as the first spine of the dorsal fin. The head contains a distinct narrow, bony, external protrusion called a humeral process. The shape and size of the humeral process helps to identify the species. In S. longirostris, the humeral process is rough, much longer than it is broad, and pointed at the end. The fish has three pairs of barbels. The maxillary barbels are on located on the upper jaw, and two pairs of mandibular barbels are on the lower jaw. The maxillary barbel is straight without any branches, without a membrane at the base. It extends about 1⁄2 as long as the head. The outer pair of mandibular barbels is a little under twice the length of the inner pair. They have short branches. The front edges of the dorsal fins and the pectoral fins of Syntontis species are hardened into stiff spines. In S. longirostris, the spine of the dorsal fin is about 2⁄3 the length of the head, slight curved, smooth in the front and serrated on the back. The remaining portion of the dorsal fin is made up of seven branching rays. The spine of the pectoral fin is slightly longer than the dorsal spine and serrated on both sides. The adipose fin is 3 times as long as it is deep. The anal fin contains four unbranched and six branched rays, and is obtusely pointed in the front. …

In the wild, the species is known throughout the Congo River basin, with the exception of the southern tributaries. The species is harvested for the aquarium trade. The reproductive habits of most of the species of Synodontis are not known, beyond some instances of obtaining egg counts from gravid females. Spawning likely occurs during the flooding season between July and October, and pairs swim in unison during spawning. The growth rate is rapid in the first year, then slows down as the fish age.