''Scoloplax'' is the only

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

in the

catfish Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive, ...

(

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 ...

Siluriformes)

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

Scoloplacidae, the spiny dwarf catfishes.

Species

The six currently recognized species in this genus are: * ''

Scoloplax baileyi ''Scoloplax'' is the only genus in the catfish (order Siluriformes) family Scoloplacidae, the spiny dwarf catfishes. Species The six currently recognized species in this genus are: * '' Scoloplax baileyi'' Rocha, Lazzarotto & Rapp Py-Danie ...

'' Rocha, Lazzarotto & Rapp Py-Daniel, 2012Rocha, R., Lazzarotto, H. & Rapp Py-Daniel, L. (2012): A New Species of ''Scoloplax'' with a Remarkable New Tooth Morphology within Loricarioidea (Siluriformes: Scoloplacidae). ''Copeia, 2012 (4): 670-677.'' * ''

Scoloplax baskini ''Scoloplax'' is the only genus in the catfish (order Siluriformes) family Scoloplacidae, the spiny dwarf catfishes. Species The six currently recognized species in this genus are: * '' Scoloplax baileyi'' Rocha, Lazzarotto & Rapp Py-Danie ...

'' Rocha, de Oliveira & Rapp Py-Daniel, 2008 * ''

Scoloplax dicra ''Scoloplax'' is the only genus in the catfish (order Siluriformes) family Scoloplacidae, the spiny dwarf catfishes. Species The six currently recognized species in this genus are: * ''Scoloplax baileyi'' Rocha, Lazzarotto & Rapp Py-Daniel ...

'' Bailey & Baskin, 1976 * ''

Scoloplax distolothrix ''Scoloplax'' is the only genus in the catfish (order Siluriformes) family Scoloplacidae, the spiny dwarf catfishes. Species The six currently recognized species in this genus are: * ''Scoloplax baileyi'' Rocha, Lazzarotto & Rapp Py-Daniel ...

Schaefer Schaefer is an alternative spelling and cognate for the German word ''schäfer'', meaning 'shepherd', which itself descends from the Old High German '' scāphare''. Variants "Shaefer", "Schäfer" (a standardized spelling in many German-speaking ...

, Weitzman & Britski, 1989 * ''

Scoloplax dolicholophia ''Scoloplax'' is the only genus in the catfish (order Siluriformes) family Scoloplacidae, the spiny dwarf catfishes. Species The six currently recognized species in this genus are: * '' Scoloplax baileyi'' Rocha, Lazzarotto & Rapp Py-Danie ...

, Weitzman & Britski, 1989 * ''

Scoloplax empousa ''Scoloplax'' is the only genus in the catfish (order Siluriformes) family Scoloplacidae, the spiny dwarf catfishes. Species The six currently recognized species in this genus are: * '' Scoloplax baileyi'' Rocha, Lazzarotto & Rapp Py-Danie ...

, Weitzman & Britski, 1989 (Pantanal dwarf catfish)

Distribution

''Scoloplax'' is distributed in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sou ...

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = National seal , national_motto = "Firm and Happy f ...

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

, and

Paraguay Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to t ...

. ''S. baskini'' is from the small tributaries of Rio Aripuanã,

Rio Madeira The Madeira River ( pt, Rio Madeira, link=no ) is a major waterway in South America. It is estimated to be in length, while the Madeira-Mamoré is estimated near or in length depending on the measuring party and their methods. The Madeira is ...

drainage, Amazonas State, Brazil. ''S. dicra'' has the largest distribution in the

Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries of Boli ...

, originating from the Amazon and

Paraguay River The Paraguay River (Río Paraguay in Spanish, Rio Paraguai in Portuguese, Ysyry Paraguái in Guarani) is a major river in south-central South America, running through Brazil, Bolivia, Paraguay and Argentina. It flows about from its headwaters i ...

basins. ''S. distolothrix'' inhabits the

Tocantins Tocantins () is one of the 26 states of Brazil. It is the newest state, formed in 1988 and encompassing what had formerly been the northern two-fifths of the state of Goiás. Tocantins covers and had an estimated population of 1,496,880 in 20 ...

- Araguaia, Xingu, and Paraguay River basins. ''S. dolicholophia'' is known from the Rio Negro basin in Brazil, as well as the Lake Amanã. ''S. empousa'' lives in the Amazon and Paraguay-

Paraná River The Paraná River ( es, Río Paraná, links=no , pt, Rio Paraná, gn, Ysyry Parana) is a river in south-central South America, running through Brazil, Paraguay, and Argentina for some ."Parana River". Encyclopædia Britannica. Encyclopædia Br ...

basins.

Description

Species of ''Scoloplax'' are readily distinguishable from other catfishes by the presence of a conspicuous

shield A shield is a piece of personal armour held in the hand, which may or may not be strapped to the wrist or forearm. Shields are used to intercept specific attacks, whether from close-ranged weaponry or projectiles such as arrows, by means of ...

-shaped

rostral Rostral may refer to: Anatomy * Rostral (anatomical term), situated toward the oral or nasal region * Rostral bone, in ceratopsian dinosaurs * Rostral organ, of certain fish * Rostral scale, in snakes and scaled reptiles Other uses * Rostral ...

plate bearing numerous large and recurved

odontode Odontodes, or dermal teeth, are hard structures found on the external surfaces of animals or near internal openings. They consist of a soft pulp surrounded by dentine and covered by a mineralized substance such as enamel, a structure similar to th ...

s. These fish have three rows of odontode-bearing plates, two

bilateral Bilateral may refer to any concept including two sides, in particular: *Bilateria, bilateral animals *Bilateralism, the political and cultural relations between two states *Bilateral, occurring on both sides of an organism ( Anatomical terms of l ...

series and one midventral series. There is also a

plate with many recurved odootodes. The

adipose fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

is absent. The greatest length reached is about SL. ''Scoloplax'' species have modified

stomach The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...

s that are enlarged, thin-walled, and clear. The

esophagus The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to t ...

enters the stomach along the dorsal side just posterior to the anterior margin of the stomach; the intestine exits the stomach ventrally. A small patch of muscular tissue represents the digestive portion of the stomach, located from the entrance of the esophagus to where the intestine exits. This modified stomach may be for

buoyancy Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the ...

control or for breathing air.

Ecology

''Scoloplax'' species are fairly common among leaf litter in clear and blackwater habitats, including

oxbow lake An oxbow lake is a U-shaped lake or pool that forms when a wide meander of a river is cut off, creating a free-standing body of water. In South Texas, oxbows left by the Rio Grande are called '' resacas''. In Australia, oxbow lakes are call ...

s, backwater pools, and well-vegetated streams.

References

{{Taxonbar, from=Q2064940 Catfish of South America Taxa named by Reeve Maclaren Bailey Taxa named by Jonathan N. Baskin Fish of the Amazon basin Fish of Bolivia Freshwater fish of Brazil Fish of Paraguay Fish of Peru Catfish genera