The Lake Victoria squeaker (''Synodontis victoriae'') 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

Kenya ) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

Burundi Burundi (, ), officially the Republic of Burundi ( rn, Repuburika y’Uburundi ; Swahili language, Swahili: ''Jamuhuri ya Burundi''; French language, French: ''République du Burundi'' ), is a landlocked country in the Great Rift Valley at the ...

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and ...

and

Uganda }), is a landlocked country in East Africa East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territor ...

where it is found in Lakes Kioga and

Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...

and the

Victorian Nile The White Nile ( ar, النيل الأبيض ') is a river in Africa, one of the two main tributaries of the Nile, the other being the Blue Nile. The name comes from the clay sediment carried in the water that changes the water to a pale color. ...

in the lower

Kagera River The Kagera River, also known as Akagera River, or Alexandra Nile, is an East African river, forming part of the upper headwaters of the Nile and carrying water from its most distant source.Stanley, H.M., 1899, Through the Dark Continent, London: G ...

and the

Malagarasi River The Malagarasi River is a river in western Tanzania, flowing through Kigoma Region, although one of its tributaries comes from southeastern Burundi. The river also forms the western border of Tabora Region, the southern border of Kagera Region and ...

drainage. 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 botani ...

in 1906, from specimens collected in the Lake Victoria at Buganga, Uganda and

Entebbe Entebbe is a city in Central Uganda. Located on a Lake Victoria peninsula, approximately southwest of the Ugandan capital city, Kampala. Entebbe was once the seat of government for the Protectorate of Uganda prior to independence, in 1962. The c ...

, Uganda by Mr. E. Degen. 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, bot ...

''victoriae'' is derived from the location where the species was originally discovered, Lake Victoria.

Description

Like all members of the genus ''Synodontis'', ''S. victoriae'' 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. victoriae'', the humeral process is rough, about times as long as it is broad, and acutely pointed. 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 some ...

. 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 long and straight without any branches, with a narrow membrane at the base. It extends almost the length of the head. The outer pair of mandibular barbels is about twice the length of the inner pair, and both pairs have slender, simple branches. The front edges of the dorsal fins and the pectoral fins of ''Syntontis'' species are hardened into stiff spines. In ''S. victoriae'', the spine of the dorsal fin is slightly shorter than the head, straight, smooth in the front and serrated on the back. The remaining portion of the dorsal fin is made up of six to seven branching rays. The spine of the pectoral fin is about the same size as the dorsal spine, and serrated on both sides. The adipose fin is 4 to 5 times as long as it is deep. The anal fin contains four unbranched and eight branched rays. The tail, or caudal fin, is deeply forked, and the upper lobe is longer. 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. victoriae'', the toothpad forms a short and 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. victoriae'', there are 19 to 21 teeth on the mandible. The body color is brown or greyish silver on the back, white on the underside, with large round darker spots, which may be indistinct. Spots sometimes appear on the caudal fin. 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 has been found in Lake Victoria and the Victoria Nile basin, including smaller tributaries and lakes. It has also been found in the

. It is found in shallow waters of lakes and rivers, most often around of depth. 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 population of the species is decreasing, largely due to the competition from introduced

Nile perch The Nile perch (''Lates niloticus''), also known as the African snook, Goliath perch, African barramundi , Goliath barramundi, Giant lates or the Victoria perch, is a species of freshwater fish in family Latidae of order Perciformes. It is wid ...

in its ecosystem. It feeds small snails, where it is able to extract the flesh without crushing the shells. It also feeds on insects, small fish, and ostracods. The growth rate is rapid in the first year, then slows down as the fish age.

References

External links

{{DEFAULTSORT:Lake Victoria Squeaker Synodontis Fish of Lake Victoria Fish of Burundi Fish of Uganda Freshwater fish of Kenya Freshwater fish of Tanzania Fish described in 1906 Taxa named by George Albert Boulenger Taxonomy articles created by Polbot