''Synodontis ilebrevis'' 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 ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Zambia Zambia (), officially the Republic of Zambia, is a landlocked country at the crossroads of Central Africa, Central, Southern Africa, Southern and East Africa, although it is typically referred to as being in Southern Africa at its most cent ...

, where it is only known from

Lake Tanganyika Lake Tanganyika () is an African Great Lake. It is the second-oldest freshwater lake in the world, the second-largest by volume, and the second-deepest, in all cases after Lake Baikal in Siberia. It is the world's longest freshwater lake. ...

. It was first described by

Jeremy John Wright Jeremy may refer to: * Jeremy (given name), a given name * Jérémy, a French given name * ''Jeremy'' (film), a 1973 film * "Jeremy" (song), a song by Pearl Jam * Jeremy (snail), a left-coiled garden snail that died in 2017 * ''Jeremy'', a 1919 ...

and

Lawrence M. Page Lawrence may refer to: Education Colleges and universities * Lawrence Technological University, a university in Southfield, Michigan, United States * Lawrence University, a liberal arts university in Appleton, Wisconsin, United States Preparator ...

in 2006, from specimens collected from Lake Tanganyika at Cape Chaitika, Zambia. The species name comes from the Latin word "''ile''", meaning intestine, and the Latin word "''bevis''", meaning short, and refers to the relatively short gut of this species.

Description

Like all members of the genus ''Synodontis'', ''S. ilebrevis'' has a strong, bony head capsule that extends back as far as the first spine of the dorsal fin. The head is about of the

standard 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 m ...

of the fish. 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. ilebrevis'', the humeral process is triangular and rough, with a poorly defined ridge on the bottom edge. The top edge is concave and the end is sharply pointed. It is about of the length of the head. The diameter of the eye is about of the length of the head. 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 has a narrow membrane attached near the base and is straight without any branches. It extends at least as far as the base of the pectoral spine, a bit less than half of length of the head. The outer pair of mandibular barbels extends just past the front of the pectoral girdle, about of the length of the head, and contains three to six weak branches, usually without secondary branches. The inner pair of mandibular barbels is about to as long as the outer pair, about of the length of the head, with three to five pairs of branches, with many secondary branches present. The skin of ''S. ilebrevis'' has a large number of tiny vertical skin folds. The exact purpose of the skin folds is not known, but is a characteristic of the species of ''Syndontis'' that are endemic to Lake Tanganyika. External sort, flat

papilla Papilla (Latin, 'nipple') or papillae may refer to: In animals * Papilla (fish anatomy), in the mouth of fish * Basilar papilla, a sensory organ of lizards, amphibians and fish * Dental papilla, in a developing tooth * Dermal papillae, part of ...

are present and give the skin a pebbled appearance. The front edges of the dorsal fins and the pectoral fins of ''Syntontis'' species are hardened into stiff spines. In ''S. ilebrevis'', the spine of the dorsal fin is short, about as long as the head, slightly curved, rough on the front and serrated on the back, and ends with short, dusky filament. The remaining portion of the dorsal fin is made up of seven branching rays. The spine of the pectoral fin is slightly curved, about as long as the dorsal fin spine, rough on the front and with large serrations on the back. The pectoral spine ends in short, dusky filament. The rest of the pectoral fins are made up of eight to nine branching rays. The adipose fin does not contain any rays, is long and well developed, and has a convex shape. The pelvic fin contains one unbranched and six branched rays. The front edge of the pelvic fin is vertically aligned with the front edge of the adipose fin. The anal fin contains three to five unbranched and seven to nine branched rays; it is vertically aligned with the center of the adipose fin. The tail, or caudal fin, is forked, with rounded lobes, and contains eleven to fifteen rays on the upper lobe, seventeen rays on the lower lobe. The mouth of the fish faces downward and has wide lips that contain

. 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 some species, this toothpad is made up of a large patch with several rows in a large cluster. In other species of ''Syndontis'', this toothpad is clearly divided into two separate groups, separated by a thin band of skin that divides the toothpad. This character is used as a method of differentiating between two different but similar species of ''Syndontis''. In ''S. ilebrevis'', the toothpad is interrupted, or separated into two distinct groups. 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. ilebrevis'', there are 50 to 66 teeth on the mandible, arranged in eight short rows. Some of the species of ''Synodontis'' have an opening or series of openings called the axillary pore. It is located on the sides of the body below the humeral process and before the pectoral fin spine. The exact function of the port is not known to scientists, although its presence has been observed in seven other catfish genera. Fish in the genus ''Acrochordonichthys'' are known to secrete a mucus with toxic properties from their axillary pore, but there is no scientific consensus as to the exact purpose of the secretion or the pore. ''S. ilebrevis'' does not have an axillary pore. The back of the fish is olive brown, covered with small, regularly-shaped, widely spaced black spots. The underside is lighter, with smaller black spots. Most of the species of ''Synodontis'' of Lake Tanganyika have a recognizable pattern consisting of dark triangles at the bases of all of the rayed fins, present in ''S. ilebrevis'', and the back edges of the fins are dusky in color. The caudal fin has a black bar that runs from the base of each lobe to the top of the fin. The barbels are white. The maximum

of known specimens is with a

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 . 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 endemic to

, which has an observed temperature range of , an approximate pH of 8.5 – 9, and dH range of 4-15. The exact habitat is unknown, but like other small species of ''Syndontis'', it probably inhabits fairly shallow, rocky coastal areas. 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. As a whole, species of ''Synodontis'' are omnivores, consuming insect larvae, algae, gastropods, bivalves, sponges, crustaceans, and the eggs of other fishes. The growth rate is rapid in the first year, then slows down as the fish age.

References

External links

{{DEFAULTSORT:Synodontis Ilebrevis ilebrevis Fish of Zambia Endemic fauna of Zambia Fish of Lake Tanganyika Fish described in 2006