''Synodontis longispinis'' 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

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 ...

to the

Republic of the Congo The Republic of the Congo (french: République du Congo, ln, Republíki ya Kongó), also known as Congo-Brazzaville, the Congo Republic or simply either Congo or the Congo, is a country located in the western coast of Central Africa to the w ...

where it is found in the Sangha River. It was first described by

Jacques Pellegrin Jacques Pellegrin (12 June 1873, Paris – 12 August 1944) was a French zoologist. In Paris, he worked under zoologist Léon Vaillant (chair of reptiles and fishes) at the ''Muséum national d'histoire naturelle''. From 1897, Pellegrin served a ...

in 1930 as ''Synodontis batesi longspinis'', a subspecies of ''S. batesi'' with an especially long dorsal fin spine, but it is presently recognized as its own species. The species name ''longispinis'' is derived from the word ''longus'', meaning long, and the word ''spinis'', meaning spine, which is a reference to the long dorsal fin spine on the fish.

Description

Like all members of the genus ''Synodontis'', ''S. longispinis'' 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 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 adipose fin is large and the tail, or caudal fin, is forked. The front edges of the dorsal fins and the pectoral fins are hardened into stiff spines. These spines can be raised into position at right angles to the body and locked into position for defensive purposes. The ability to lock the spines into place comes from several small bones attached to the spine, and once raised, the spines cannot be folded down by exerting pressure on the tip. The fish has 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. On the lower jaw, or mandible, the teeth are attached to flexible, stalk-like structures and described as "s-shaped" or "hooked". The maximum

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 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 only known from its type locality in the Sangha River, but it may be more widespread than is currently known. The fish is harvested for human consumption. As a whole, species of ''Synodontis'' are omnivores, consuming insect larvae, algae, gastropods, bivalves, sponges, crustaceans, and the eggs of other fishes. 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=Q3756254 longispinis Freshwater fish of Africa Fish of the Republic of the Congo Endemic fauna of the Republic of the Congo Taxa named by Jacques Pellegrin Fish described in 1930