Synodontis
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. Synodontis has over 131 different species within the genus. Synodontis are also known as squeakers, due to their ability to make stridulatory sounds through their pectoral fin spines when handled or disturbed. 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. Synodontis may also squeak when they are taken out of the water. These catfish are small- to medium-sized fish with many species exhibiting attractive spotted markings. Some species are also known for naturally swimming belly-up, earning the name upside-down catfish. 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.
Distribution
Synodontis is a freshwater catfish that is most commonly found throughout Africa, occurring mostly in Central and West Africa. Synodontis is the most widely distributed mochokidae genus, occurring throughout most of the freshwaters of sub-Saharan Africa and the Nile River system. They can live in freshwaters which can be creeks, ponds, streams, lakes, and rivers. 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, which includes the non-endemic species S. victoriae. This radiation is thought to have evolved relatively recently, having diversified within full lacustrine conditions. This is also the case for other endemic Lake Tanganyika lineages such as mastacembelid eels and platythelphusid crabs for example. Lake Tanganyikan Synodontis have also been shown to be Müllerian mimics, and that at least one species is a brood parasite.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.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. They are bottom-feeders and may be detritivores, some species may also be able to adapt to filter feeding. This allows them to cope with seasonal and habitat changes and gives them a better ability to colonize different habitats. 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. 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. 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. Species of Synodontis have been noted to reproduce with the flooding period of the rainy season.Relationship to humans
Many Synodontis species are prized ornamental fish in the fishkeeping hobby. While species of Synodontis are prized for their color or behavior, others are wanted for food. Some of the bigger species in the genus are important food sources for the people in Africa.Species
There are currently 131 recognized species in this genus: Synodontis accounts for about one-quarter of African catfish species. This genus has more members than any other African teleost genus other than Barbus and Haplochromis.Newer species are listed with references.Synodontis acanthomias Boulenger, 1899Synodontis acanthoperca Friel & Vigliotta, 2006Synodontis afrofischeri Hilgendorf, 1888 Synodontis alberti Schilthuis, 1891 Synodontis albolineatus Pellegrin, 1924Synodontis angelicus Schilthuis, 1891 Synodontis annectens Boulenger, 1911Synodontis ansorgii Boulenger, 1911Synodontis arnoulti Román, 1966Synodontis aterrimus Poll & Roberts, 1968Synodontis bastiani Daget, 1948Synodontis batensoda Rüppell, 1832 Synodontis batesii Boulenger, 1907Synodontis brichardi Poll, 1959Synodontis budgetti Boulenger, 1911Synodontis camelopardalis Poll, 1971Synodontis carineae Vreven & Ibala Zamba, 2011Synodontis caudalis Boulenger, 1899Synodontis caudovittatus Boulenger, 1901Synodontis centralis Poll, 1971Synodontis clarias Synodontis comoensis Daget & Lévêque, 1981Synodontis congicus Poll, 1971Synodontis contractus Vinciguerra, 1928 Synodontis courteti Pellegrin, 1906Synodontis cuangoanus Poll, 1971Synodontis decorus Boulenger, 1899 Synodontis dekimpei Paugy, 1987Synodontis depauwi Boulenger, 1899Synodontis dhonti Boulenger, 1917Synodontis dorsomaculatus Poll, 1971Synodontis eupterus Boulenger, 1901 Synodontis filamentosus Boulenger, 1901Synodontis flavitaeniatus Boulenger, 1919 Synodontis frontosus Vaillant, 1895Synodontis fuelleborni Hilgendorf & Pappenheim, 1903 Synodontis geledensis Günther, 1896 Synodontis gobroni Daget, 1954Synodontis grandiops Wright & Page, 2006Synodontis granulosus Boulenger, 1900Synodontis greshoffi Schilthuis, 1891Synodontis guttatus Günther, 1865Synodontis haugi Pellegrin, 1906Synodontis ilebrevis Wright & Page, 2006Synodontis irsacae Matthes, 1959Synodontis iturii Steindachner, 1911Synodontis katangae Poll, 1971Synodontis khartoumensis Abu Gideiri, 1967Synodontis koensis Pellegrin, 1933Synodontis kogonensis Musschoot & Lalèyè, 2008Synodontis laessoei Norman, 1923Synodontis leopardinus Pellegrin, 1914 Synodontis leopardus Pfeffer, 1896Synodontis levequei Paugy, 1987Synodontis longirostris Boulenger, 1902Synodontis longispinis Pellegrin, 1930Synodontis lucipinnis Wright & Page, 2006Synodontis lufirae Poll, 1971Synodontis macrophthalmus Poll, 1971Synodontis macrops Greenwood, 1963Synodontis macropunctatus Wright & Page, 2008Synodontis macrostigma Boulenger, 1911 Synodontis macrostoma Skelton & White, 1990 Synodontis manni De Vos, 2001 Synodontis marmoratus Lönnberg, 1895Synodontis matthesi Poll, 1971Synodontis melanopterus Boulenger, 1903Synodontis melanostictus Boulenger, 1906Synodontis membranacea Synodontis multimaculatus Boulenger, 1902Synodontis multipunctatus Boulenger, 1898 Synodontis nebulosus Peters, 1852 Synodontis ngouniensis De Weirdt, Vreven & Fermon, 2008Synodontis nigrita Valenciennes, 1840Synodontis nigriventris David, 1936 Synodontis nigromaculatus Boulenger, 1905 Synodontis njassae Keilhack, 1908 Synodontis notatus Vaillant, 1893 Synodontis nummifer Boulenger, 1899Synodontis obesus Boulenger, 1898Synodontis ocellifer Boulenger, 1900Synodontis omias Günther, 1864Synodontis orientalis Seegers, 2008Synodontis ornatipinnis Boulenger, 1899Synodontis ornatissimus Gosse, 1982Synodontis ouemeensis Musschoot & Lalèyè, 2008Synodontis pardalis Boulenger, 1908Synodontis petricola Matthes, 1959 Synodontis pleurops Boulenger, 1897 Synodontis polli Gosse, 1982Synodontis polyodon Vaillant, 1895Synodontis polystigma Boulenger, 1915Synodontis pulcher Poll, 1971Synodontis punctifer Daget, 1965Synodontis punctulatus Günther, 1889Synodontis punu Vreven & Milondo, 2009Synodontis rebeli Holly, 1926Synodontis resupinatus Boulenger, 1904Synodontis ricardoae Seegers, 1996 Synodontis robbianus Smith, 1875Synodontis robertsi Poll, 1974Synodontis ruandae Matthes, 1959Synodontis rufigiensis Bailey, 1968Synodontis rukwaensis Hilgendorf & Pappenheim, 1903 Synodontis schall Synodontis schoutedeni David, 1936Synodontis serpentis Whitehead, 1962 Synodontis serratus Rüppell, 1829Synodontis smiti Boulenger, 1902Synodontis soloni Boulenger, 1899Synodontis sorex Günther, 1864Synodontis steindachneri Boulenger, 1913Synodontis tanganyicae Borodin, 1936Synodontis tessmanni Pappenheim, 1911Synodontis thamalakanensis Fowler, 1935Synodontis thysi Poll, 1971Synodontis tourei Daget, 1962Synodontis unicolor Boulenger, 1915Synodontis vaillanti Boulenger, 1897Synodontis vanderwaali Skelton & White, 1990Synodontis velifer Norman, 1935Synodontis vermiculatus Daget, 1954Synodontis victoriae Boulenger, 1906 Synodontis violaceus Pellegrin, 1919Synodontis voltae Román, 1975Synodontis waterloti Daget, 1962Synodontis woleuensis Friel & Sullivan, 2008Synodontis woosnami Boulenger, 1911 Synodontis xiphias Günther, 1864Synodontis zambezensis Peters, 1852 Synodontis zanzibaricus Peters, 1868