''Macrognathus'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of eel-like

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Mastacembelidae The Mastacembelidae are a family of fishes, known as the spiny eels. The Mastacembelids are part of the Order Synbranchiformes, the swamp eels, which are part of the Actinopterygii (ray-finned fishes). In an evaluation of the family in 2004, the ...

of the

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

Synbranchiformes Synbranchiformes, often called swamp eels, is an order of ray-finned fishes that are eel-like but have spiny rays, indicating that they belong to the superorder Acanthopterygii. Taxonomy No synbrachiform fossil is known. The Mastacembeloidei were ...

. These fish are distributed throughout most of

South South is one of the cardinal directions or Points of the compass, compass points. The direction is the opposite of north and is perpendicular to both east and west. Etymology The word ''south'' comes from Old English ''sūþ'', from earlier Pro ...

and

Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...

. ''Macrognathus'' species feed on small aquatic

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

e as well as oligochaetes.

Appearance and anatomy

Most ''Macrognathus'' species attain in length, but a few surpass this size, with the largest being ''M. aral'' at up to . ''Macrognathus'' are mostly similar to ''

Mastacembelus ''Mastacembelus'' is a genus of many species of spiny eel fish from the family Mastacembelidae. They are native to Africa (c. 45 species) and Asia (c. 15 species). Most are found in rivers and associated systems (even in rapids), but there are al ...

''. However, they differ in a more modified rostrum, which may be slightly to significantly larger and longer than those found in ''Mastacembelus''. This serves not only to find food but also to help gather food.

In the aquarium

A number of species of this genus are popular

aquarium An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...

fish. These include the lesser spiny eel, ''Macrognathus aculeatus'', the spotfinned spiny eel, ''Macrognathus siamensis'', as well as others.

Species

According to

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

, there are currently 25 recognized species in this genus. According to Catalog of Fishes, one of these, ''M. malabaricus'', belongs in the genus ''

'' instead of ''Macrognathus'' and another, ''M. taeniagaster'', is considered a

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...

of ''M. circumcinctus''. * ''

Macrognathus aculeatus The lesser spiny eel, ''Macrognathus aculeatus'', is a Southeast Asian tropical freshwater fish belonging to the family Mastacembelidae. They are uncommonly found in aquaria. Physical characteristics The eel has an upper-body that is yellow, ...

'' (

Bloch Bloch is a surname of German origin. Notable people with this surname include: A–F * (1859-1914), French rabbi *Adele Bloch-Bauer (1881-1925), Austrian entrepreneur *Albert Bloch (1882–1961), American painter * (born 1972), German motor journal ...

, 1786) (Lesser spiny eel) * ''

Macrognathus albus ''Macrognathus'' is a genus of eel-like fish of the family Mastacembelidae of the order Synbranchiformes. These fish are distributed throughout most of South and Southeast Asia. ''Macrognathus'' species feed on small aquatic insect larvae as ...

'' * ''

Macrognathus aral ''Macrognathus aral'', the one-stripe spiny eel, is a small fish from Pakistan, India, Bangladesh, Nepal and Myanmar Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even i ...

'' (

& J. G. Schneider, 1801) (Onestripe spiny eel) * ''

Macrognathus aureus ''Macrognathus'' is a genus of eel-like fish of the family Mastacembelidae of the order Synbranchiformes. These fish are distributed throughout most of South and Southeast Asia. ''Macrognathus'' species feed on small aquatic insect larvae as ...

'' Britz, 2010 * ''

Macrognathus caudiocellatus ''Macrognathus'' is a genus of eel-like fish of the family Mastacembelidae of the order Synbranchiformes. These fish are distributed throughout most of South and Southeast Asia. ''Macrognathus'' species feed on small aquatic insect larvae as ...

'' (

Boulenger Boulenger is a surname. Notable people with the surname include: * Benjamin Boulenger (born 1990), French footballer * Edward George Boulenger (1888–1946), British zoologist, director of aquarium at London Zoo * George Albert Boulenger (1858–1 ...

, 1893) * ''

Macrognathus circumcinctus ''Macrognathus'' is a genus of eel-like fish of the family Mastacembelidae of the order Synbranchiformes. These fish are distributed throughout most of South and Southeast Asia. ''Macrognathus'' species feed on small aquatic insect larvae as ...

'' ( Hora, 1924) * ''

Macrognathus dorsiocellatus ''Macrognathus'' is a genus of eel-like fish of the family Mastacembelidae of the order Synbranchiformes. These fish are distributed throughout most of South and Southeast Asia. ''Macrognathus'' species feed on small aquatic insect larvae as ...

'' Britz, 2010 * ''

Macrognathus fasciatus ''Macrognathus fasciatus'' is a species of spiny eel found in the Manimala River Manimala River or Manimalayar is a 92km long river which flows through South and Central Kerala. The river used to be wrongly considered as a tributary of Pamba R ...

'' Plamoottil &

Abraham Abraham, ; ar, , , name=, group= (originally Abram) is the common Hebrew patriarch of the Abrahamic religions, including Judaism, Christianity, and Islam. In Judaism, he is the founding father of the special relationship between the Jew ...

, 2014Plamoottil, M. & Abraham, N.P. (2014): ''Macrognathus fasciatus'' (Synbranchiformes; Mastacembelidae) - a new fish species from Kerala, India. ''Journal of Experimental Zoology, India, 17 (1): 49-54.'' * '' Macrognathus guentheri'' ( F. Day, 1865) (Malabar spiny eel) * '' Macrognathus keithi'' ( Herre, 1940) * '' Macrognathus lineatomaculatus'' Britz, 2010 * '' Macrognathus maculatus'' (

G. Cuvier Jean Léopold Nicolas Frédéric, Baron Cuvier (; 23 August 1769 – 13 May 1832), known as Georges Cuvier, was a French naturalist and zoologist, sometimes referred to as the "founding father of paleontology". Cuvier was a major figure in nat ...

, 1832) (Frecklefin eel) * '' Macrognathus malabaricus'' ( Jerdon, 1849) * '' Macrognathus meklongensis'' T. R. Roberts, 1986 * '' Macrognathus morehensis'' Arunkumar & Tombi Singh, 2000 * '' Macrognathus obscurus'' Britz, 2010 * '' Macrognathus pancalus'' F. Hamilton, 1822 (Barred spiny eel) * '' Macrognathus pavo'' Britz, 2010 * '' Macrognathus pentophthalmos'' ( Gronow, 1854) (

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

?) * '' Macrognathus semiocellatus'' T. R. Roberts, 1986 * ''

Macrognathus siamensis The Peacock Eel or Spotfin Spiny Eel (''Macrognathus siamensis)'' is a spiny eel found in freshwater habitats throughout Southeast Asia. They are commercially important as food and aquarium fish. Distribution The peacock eel is native to the ...

'' ( Günther, 1861) (Peacock eel) * '' Macrognathus siangensis'' Arunkumar, 2016 * '' Macrognathus taeniagaster'' ( Fowler, 1935) * '' Macrognathus tapirus''

Kottelat Maurice Kottelat (born 16 July 1957 in Delémont, SwitzerlandC ...

& Widjanarti, 2005 * '' Macrognathus zebrinus'' ( Blyth, 1858) (Zebra spiny eel)

References

Mastacembelidae Fish of Southeast Asia {{Synbranchiformes-stub