Synodontis

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Synodontis
Temporal range: Early Miocene–Recent
Synodontis njassae 01 ssj 20050321.jpg
Synodontis njassae
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Family: Mochokidae
Genus: Synodontis
G. Cuvier, 1816
Type species
Silurus clarias
Synonyms
  • Leiosynodontis Bleeker, 1862
  • PseudosynodontisBleeker, 1862

Synodontis is the largest genus of mochokid catfishes. It is the biggest genus within the 10 genera and 190 different species in the family Mochokidae. [1] Synodontis has over 131 different species within the genus. [2] Synodontis are also known as squeakers, due to their ability to make stridulatory sounds through their pectoral fin spines when handled or disturbed. [3] Synodontis make a sound that sounds like squeaking by rubbing their spines together. They do this when they have been frightened or when they become angry. [2] Synodontis may also squeak when they are taken out of the water. [1] These catfish are small- to medium-sized fish [4] with many species exhibiting attractive spotted markings. Some species are also known for naturally swimming belly-up, earning the name upside-down catfish. [3] Some of these species are Synodontis contractus and Synodontis nigriventris . While some of these species are known to swim upside down, another species, Synodontis multipunctatus , is a brood parasitic cuckoo catfish,there are two other species Synodontis petricola and Synodontis grandiops are also called brood parasitic cuckoo catfish. [1]

Contents

Distribution

Synodontis petricola Synodontis petricola.jpg
Synodontis petricola

Synodontis is a freshwater catfish that is most commonly found throughout Africa, occurring mostly in Central and West Africa. [1] Synodontis is the most widely distributed mochokidae genus, occurring throughout most of the freshwaters of sub-Saharan Africa and the Nile River system. [3] They can live in freshwaters which can be creeks, ponds, streams, lakes, and rivers. [2] Their distribution is similar to that of cichlid fishes, however, unlike cichlids the majority of their diversity occurs in rivers not lakes.

Evolutionary history

Synodontis catfish form a small endemic radiation in Lake Tanganyika, [1] [5] [6] which includes the non-endemic species S. victoriae. This radiation is thought to have evolved relatively recently (~5.5. Million years ago), having diversified within full lacustrine conditions. [5] [6] This is also the case for other endemic Lake Tanganyika lineages such as mastacembelid eels [7] and platythelphusid crabs for example. [8] Lake Tanganyikan Synodontis have also been shown to be Müllerian mimics, [9] and that at least one species (Synodontis multipunctatus) is a brood parasite. [10]

Fossil record

The earliest fossils of Synodontis in East African are from the Early Miocene. Many Synodontis fossils are the spines because they are very sturdy and so they are preserved better. The fossils of spines that are found are used to determine the family or genera of the fish but it cannot determine the species. Synodontis species that have survived and are still living can be identified by the shape of their whisker like organs on their heads called barbels, which relate to touch. The can also be identified by the color of their skin, the skull bones, and the number and length of the teeth. [11]

Ecology

Synodontis species are omnivorous generalists, feeding on a wide spectrum of different foods and are largely unspecialized. Insects, crustaceans, mollusks, annelids, seeds, and algae have been found in the stomachs of different species of Synodontis. [2] They are bottom-feeders and may be detritivores, some species may also be able to adapt to filter feeding. [4] This allows them to cope with seasonal and habitat changes and gives them a better ability to colonize different habitats. [1] Different Synodontis species have somewhat different growth rates but most of them are fairly similar. Females of a species are generally larger than the males. There is a great increase in growth the first year in both male and female and then the growth slows down as they become older. [12] The form and structure of these fish are very different compared to other fish. The size and shape of the mouth are distinct because of its ventral mouth and these fish usually are triangular or cylindrical when looking at it from the side. [2] Not much is known about the reproduction in these fish. It has been determined that July to October is when they spawn and that they swim in pairs during this spawning time. [2] Species of Synodontis have been noted to reproduce with the flooding period of the rainy season. [4]

Relationship to humans

Synodontis nigriventris is a popular aquarium fish. Synodontis.jpg
Synodontis nigriventris is a popular aquarium fish.

Many Synodontis species are prized ornamental fish in the fishkeeping hobby. [3] While some of the Synodontis species are prized because of their color or behavior, other species are wanted for food. Some of the bigger species in the genus are important food sources for the people in Africa. [1]

Species

There are currently 131 recognized species in this genus: [13] Synodontis accounts for about one-quarter of African catfish species. [1] This genus has more members than any other African teleost genus other than Barbus and Haplochromis . [4]

Newer species are listed with references.

Related Research Articles

<i>Chiloglanis</i> Genus of fishes

Chiloglanis is a genus of upside-down catfishes native to Africa. These species have modified lips and barbels that form a suckermouth. They also have a naked (scaleless) body. Sexual dimorphism has been reported in Chiloglanis. The adult males of many of these species have elongate anal and caudal fins. Also, males may have an enlarged humeral process.

Synodontis aterrimus, known as the network synodontis, is a species of upside-down catfish that is endemic to the Democratic Republic of the Congo where it is found in the middle Congo Basin. It was first described by Max Poll and Tyson R. Roberts in 1968. The original specimens were obtained in Bokuma, on the Congo River in what is now the Democratic Republic of the Congo. The species name aterrimus means "very black", referring to the dark coloration on the underside of the body.

<i>Synodontis brichardi</i> Species of fish

Synodontis brichardi, known as Brichard's synodontis, is a species of upside-down catfish that is endemic to the Democratic Republic of the Congo where it occurs in the rapids of the lower Congo River. It was first described by Max Poll in 1959. The original specimens were obtained from the rapids at Kinsuka, Kinshaa, Zaire. The species name brichardi is named in honor of Pierre Brichard, an aquarium fish exporter who first discovered the fish.

<i>Synodontis budgetti</i> Species of fish

Synodontis budgetti, known as Budgett's synodontis, is a species of upside-down catfish native to Benin, Cameroon, Central African Republic, Côte d'Ivoire, Mali, Niger, and Nigeria where it occurs in Lake Nokoue and the Niger. It was first described by Belgian-British zoologist George Albert Boulenger in 1911, from specimens collected in Lokoja, Nigeria. The species name budgetti comes from name of the collector of the original specimen, J.S. Budgett.

Synodontis camelopardalis, known as the giraffe synodontis, is a species of upside-down catfish that is endemic to the Democratic Republic of the Congo where it is only known to occur in the Tshuapa River. It was first described by Max Poll in 1971. The original specimens were obtained in Eala, on the Ruki River in the central Congo River Basin. The species name camelopardalis refers to the giraffe, Giraffa camelopardalis, in reference to the coloration of the fish.

<i>Synodontis centralis</i> Species of fish

Synodontis centralis is a species of upside-down catfish that is endemic to the Democratic Republic of the Congo where it occurs in the middle Congo Basin. It was first described by Max Poll in 1971. The original specimens were obtained in Ndwa village, Kunungu, Zaire. The species name centralis refers to its habitat in the central Congo Basin.

<i>Synodontis courteti</i> Species of fish

Synodontis courteti is a species of upside-down catfish that is native to the countries of the Niger and Chad Basins. It has been recorded in Cameroon, Chad, Ghana, Guinea, Mali, Niger, and Nigeria. It was first described by French zoologist Jacques Pellegrin in 1906, from specimens collected in the Chari River, Chad. The species name courteti is named after M. Courtet, member of the "Mission Chari-Lac Chad".

Synodontis dorsomaculatus is a species of upside-down catfish that is endemic to the Democratic Republic of the Congo where it occurs in the Lukusi and upper Lualaba Rivers and the Upemba lakes. It was first described by Max Poll in 1971. The original specimens were obtained in Kadia, Kisale, Katanga, in what is now the Democratic Republic of the Congo. The species name dorsomaculatus is derived from the word dorso, meaning "back", and the word maculatus, meaning "spotted", a reference to the dark round spots on the fish's back.

<i>Synodontis filamentosus</i> Species of fish

Synodontis filamentosus, known as the longfin synodontis, is a species of upside-down catfish that is native to the basins of the Nile, Volta and Niger Rivers as well as the Chad Basin. It was first described by British-Belgian zoologist George Albert Boulenger in 1901, from specimens obtained near the mouth of Lake No, on the White Nile in Sudan. The species name filamentosus comes from the elongated rays of the dorsal and caudal fins.

<i>Synodontis geledensis</i> Species of fish

Synodontis geledensis, known as the Geledi squeaker, is a species of upside-down catfish that is native to Ethiopia, Kenya and Somalia where it can be found in the Lorian Swamp, the Shebelle and Ewaso Ng'iro rivers. It was first described by German zoologist Albert Günther in 1896, from specimens obtained near Geledi, on the Shebeli River in east Africa. The species name geledensis comes from Geledi, Somalia, the location where the first specimens were first found.

<i>Synodontis katangae</i> Species of fish

Synodontis katangae is a species of upside-down catfish that is native to the Democratic Republic of the Congo and Zambia where it is found in the Congo Basin. It was first described by Max Poll in 1971. The original specimens were obtained in Lukonzolwa, on Lake Mweru, in what is now the Democratic Republic of the Congo. The species name katangae is a reference to the Katanga province in the Democratic Republic of the Congo, where the species was first found.

<i>Synodontis leopardinus</i> Species of fish

Synodontis leopardinus, known as the leopard squeaker, is a species of upside-down catfish that is native to the Cunene, Okavango and upper Zambezi Rivers. It was first described by Jacques Pellegrin in 1914. The original specimens were obtained in Barotsés, on the Zambezi River in Zambia. The species name leopardinus means "leopard like", referring to the fish's small black spots on a yellowish body.

Synodontis longispinis is a species of upside-down catfish that is endemic to the Republic of the Congo where it is found in the Sangha River. It was first described by Jacques Pellegrin 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.

Synodontis lufirae is a species of upside-down catfish that is endemic to the Democratic Republic of the Congo where it occurs in the Lufira River drainage. It was first described by Max Poll in 1971. The original specimens were obtained in the Lufira River, in the Congo River Basin. The species name lufirae is named for the river in which the species is found.

<i>Synodontis nigromaculatus</i> Species of fish

Synodontis nigromaculatus, known as the spotted squeaker, the blackspotted squeaker, or the speckled squeaker, is a species of upside-down catfish that is found widely in southern Africa. It has been identified in Angola, Botswana, the Democratic Republic of the Congo, Mozambique, Namibia, South Africa, Zambia, and Zimbabwe. It was first described by British-Belgian zoologist George Albert Boulenger in 1905, from specimens collected in Lake Bangweulu in Zambia.

<i>Synodontis ocellifer</i> Species of fish

Synodontis ocellifer, known as the ocellated synodontis, is a species of upside-down catfish native to the rivers of northern and western Africa. It has been reported in 10 countries, including Burkina Faso, Cameroon, Chad, Gambia, Ghana, Guinea, Mali, Niger, Nigeria, and Senegal. It was first described by Belgian-British zoologist George Albert Boulenger in 1900, from specimens collected in Kunchow Creek, in Gambia. The species name ocellifer comes from the Latin word ocellus, meaning "eye", and the Latin word ifer, meaning "to carry", which refers to the black spots, possibly with white centers found on the sides.

<i>Synodontis ornatipinnis</i> Species of fish

Synodontis ornatipinnis, known as the barfin synodontis, is a species of upside-down catfish that is native to the Congo Basin of the Democratic Republic of the Congo and Zambia. It was first described by British-Belgian zoologist George Albert Boulenger in 1899, from specimens collected in Mbandaka, on the Congo River in what is now the Democratic Republic of the Congo. The species name ornatipinnis means "ornate fins".

Synodontis pulcher is a species of upside-down catfish that is endemic to the Democratic Republic of the Congo where it is only known from Stanley Pool. It was first described by Max Poll in 1971. The original specimens were obtained from Stanley Pool, on the Congo River in what is now the Democratic Republic of the Congo. The species name pulcher means "beautiful", referring to the markings on the body.

<i>Synodontis sorex</i> Species of fish

Synodontis sorex is a species of upside-down catfish that is widely distributed in the rivers of northern Africa. It was first described by German zoologist Albert Günther in 1864, from specimens obtained in the upper Nile River, near Khartoum, Sudan. The species name sorex comes from the Latin word for shrew or shrew-mouse, the allusion was not explained. It possibly describes the pointed snout or the long, slender teeth.

Synodontis unicolor is a species of upside-down catfish that is endemic to the Democratic Republic of the Congo where it occurs in the area of Luapula-Mweru. It was first described by George Albert Boulenger in 1915. The original specimens were obtained in Kasenga, on the Luapula River in what is now the Democratic Republic of the Congo. The species name unicolor means "one color", referring to the uniform dark-brown coloration on the body and fins.

References

  1. 1 2 3 4 5 6 7 8 Stephan Koblmüller; Christian Sturmbauer; Erik Verheyen; Axel Meyer & Walter Salzburger (2006). "Mitochondrial phylogeny and phylogeography of East African squeaker catfishes (Siluriformes: Synodontis)". BMC Evolutionary Biology . 6: 49. doi: 10.1186/1471-2148-6-49 . PMC   1543664 . PMID   16784525.
  2. 1 2 3 4 5 6 John P. Friel & Thomas R. Vigliotta (March 2, 2009). "Mochokidae Jordan 1923: African squeaker and suckermouth catfishes". Tree of Life Web Project . Retrieved December 4, 2012.
  3. 1 2 3 4 5 Friel, John P.; Vigliotta, Thomas R. (2006). "Synodontis acanthoperca, a new species from the Ogôoué River system, Gabon with comments on spiny ornamentation and sexual dimorphism in mochokid catfishes (Siluriformes: Mochokidae)" (PDF). Zootaxa . 1125: 45–56.
  4. 1 2 3 4 Lalèyè, Philippe; Chikou, Antoine; Gnohossou, Pierre; Vandewalle, Pierre; Philippart, Jean Claude; Teugels, Guy (2006). "Studies on the biology of two species of catfish Synodontis schall and Synodontis nigrita (Ostariophysi : Mochokidae) from the Ouémé River, Bénin" (PDF). Belgian Journal of Zoology . 136 (2): 193–201. Archived from the original (PDF) on 2009-12-29.
  5. 1 2 Julia J. Day & Mark Wilkinson (2006). "On the origin of the Synodontis catfish species flock from Lake Tanganyika" (PDF). Biology Letters . 2 (4): 548–552. doi:10.1098/rsbl.2006.0532. PMC   1833983 . PMID   17148285.
  6. 1 2 J. J. Day; R. Bills & J. P. Friel (2009). "Lacustrine radiations in African Synodontis catfish". Journal of Evolutionary Biology . 22 (4): 805–817. doi: 10.1111/j.1420-9101.2009.01691.x .
  7. Brown KJ, Rüber L, Bills R, Day JJ (2010). "Mastacembelid eels support Lake Tanganyika as an evolutionary hotspot of diversification". BMC Evolutionary Biology. 10: 188. doi: 10.1186/1471-2148-10-188 . PMC   2903574 . PMID   20565906.
  8. Marijnissen SA, Michel E, Daniels SR, Erpenbeck D, Menken SB, Schram FR (August 2006). "Molecular evidence for recent divergence of Lake Tanganyika endemic crabs (Decapoda: Platythelphusidae)". Molecular Phylogenetics and Evolution. 40 (2): 628–34. doi:10.1016/j.ympev.2006.03.025. PMID   16647274.
  9. Wright JJ (February 2011). "Conservative coevolution of Müllerian mimicry in a group of rift lake catfish". Evolution; International Journal of Organic Evolution. 65 (2): 395–407. doi:10.1111/j.1558-5646.2010.01149.x. PMID   20964683.
  10. Sato T (1986). "A brood parasitic catfish of mouthbrooding cichlid fishes in Lake Tanganyika". Nature. 323 (6083): 58–9. doi:10.1038/323058a0. PMID   3748180.
  11. Pinton A, Fara E, Otero O (January 2006). "Spine anatomy reveals the diversity of catfish through time: a case study of Synodontis (Siluriformes)". Die Naturwissenschaften. 93 (1): 22–6. doi:10.1007/s00114-005-0051-4. PMID   16261332.
  12. H. M. Bishai & Y. B. Abu Gideiri (1965). "Studies on the biology of genus Synodontis at Khartoum". Hydrobiologia . 26 (1–2): 85–97. doi:10.1007/BF00142257.
  13. Froese, Rainer and Pauly, Daniel, eds. (2014). Species of Synodontis in FishBase . June 2014 version.
  14. 1 2 3 Jeremy J. Wright & Lawrence M. Page (2006). "Taxonomic revision of Lake Tanganyikan Synodontis (Siluriformes: Mochokidae)" (PDF). Bulletin of the Florida Museum of Natural History . 46 (4): 99–154.
  15. Jeremy J. Wright & Lawrence M. Page (2008). "A new species of Synodontis (Siluriformes: Mochokidae) from tributaries of the Kasai River in northern Angola". Copeia . 2008 (2): 294–300. doi:10.1643/CI-07-040.