''Synodontis polystigma'' 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 upper
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 con ...
of 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 ...
and
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 ...
.
[ It was first described by ]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 botani ...
in 1915. The original specimens were obtained at Lukonzolwa, in Lake Mweru, in what is now the Democratic Republic of the Congo.[ The species name ''polystigma'' is derived from ''poly'', meaning "many" and ''stigma'', meaning "mark or spot", referring to the numerous black spots on the body and fins of the species.][
]
Description
Like all members of the genus ''Synodontis'', ''S. polystigma'' 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 ]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 occurs in the Luapula-Mweru River system.[ 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=Q2835496
polystigma
Freshwater fish of Africa
Fish of the Democratic Republic of the Congo
Fish of Zambia
Taxa named by George Albert Boulenger
Fish described in 1915