''Synodontis longirostris'', known as the eyespot synodontis, is a species of

upside-down catfish The name upside-down catfish is most commonly used by aquarists to refer to the mochokid catfish '' Synodontis nigriventris'' alternately known to ichthyologists as the blotched upside-down catfish or false upside-down catfish. However, a number ...

that is native to the

Democratic Republic of the Congo The Democratic Republic of the Congo (french: République démocratique du Congo (RDC), colloquially "La RDC" ), informally Congo-Kinshasa, DR Congo, the DRC, the DROC, or the Congo, and formerly and also colloquially Zaire, is a country in ...

where it occurs in the

Congo Basin The Congo Basin (french: Bassin du Congo) is the sedimentary basin of the Congo River. The Congo Basin is located in Central Africa, in a region known as west equatorial Africa. The Congo Basin region is sometimes known simply as the Congo. It c ...

. It was first described by British-Belgian zoologist

George Albert Boulenger George Albert Boulenger (19 October 1858 – 23 November 1937) was a Belgian-British zoologist who described and gave scientific names to over 2,000 new animal species, chiefly fish, reptiles, and amphibians. Boulenger was also an active botan ...

in 1902, from specimens obtained in the

Ubangi River The Ubangi River (), also spelled Oubangui, is the largest right-bank tributary of the Congo River in the region of Central Africa. It begins at the confluence of the Mbomou (mean annual discharge 1,350 m3/s) and Uele Rivers (mean annual discha ...

at Banzyville. The

species name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bo ...

''longirostris'' comes from the Latin word ''longus'', meaning "long", and the Latin word ''rostrum'', meaning snout, referring to the long snout on this species.

Description

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 In fish anatomy and turtle anatomy, a barbel is a slender, whiskerlike sensory organ near the mouth. Fish that have barbels include the catfish, the carp, the goatfish, the hagfish, the sturgeon, the zebrafish, the black dragonfish and s ...

. 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 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 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. The tail, or caudal fin, is deeply notched. All members of ''Syndontis'' have a structure called a premaxillary toothpad, which is located on the very front of the upper jaw of the mouth. This structure contains several rows of short, chisel-shaped teeth. In ''S. longirostris'', the toothpad forms a short, broad band. On the lower jaw, or mandible, the teeth of ''Syndontis'' are attached to flexible, stalk-like structures and described as "s-shaped" or "hooked". The number of teeth on the mandible is used to differentiate between species; in ''S. longirostris'', there are about 24 teeth on the mandible. The base body color is olive-brown, with large round black spots in three series on the body. The maximum

total length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish ...

of the species is . Generally, females in the genus ''Synodontis'' tend to be slightly larger than males of the same age.

Habitat and behavior

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.

References

External links

{{Taxonbar, from=Q3754994 longirostris Freshwater fish of Africa Fish of the Democratic Republic of the Congo Endemic fauna of the Democratic Republic of the Congo Taxa named by George Albert Boulenger Fish described in 1902