''Scleronema'' 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 pencil catfishes native to

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 southe ...

. They are a member of the subfamily

Trichomycterinae The Trichomycterinae are a subfamily of catfishes (order Siluriformes) of the family Trichomycteridae. It includes six genera, '' Bullockia'', '' Hatcheria'', '' Rhizosomichthys'', and '' Eremophilus'', all monotypic, '' Silvinichthys'' with two ...

. Species of Scleronema are geographically distributed in the La Plata basin and Atlantic coastal drainages from

Southern Brazil The South Region of Brazil (; ) is one of the five regions of Brazil. It includes the states of Paraná, Rio Grande do Sul, and Santa Catarina, and covers , being the smallest region of the country, occupying only about 6.76% of the territory ...

, Southern

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 th ...

, Northeastern

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

and

Uruguay Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering ...

. They inhabit rivers or streams with sand or gravel-bottoms across the Pampa grasslands. In Greek, Scleronema means "hard filament."

Species

There are currently three recognized species in this genus: * '' Scleronema angustirostre'' ( Devincenzi, 1942) * '' Scleronema minutum'' (

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 ...

, 1891) * '' Scleronema operculatum'' C. H. Eigenmann, 1917 ''S. minutum'' and ''S. operculatum'' both originate from

Rio Grande do Sul Rio Grande do Sul (, , ; "Great River of the South") is a Federative units of Brazil, state in the South Region, Brazil, southern region of Brazil. It is the Federative_units_of_Brazil#List, fifth-most-populous state and the List of Brazilian st ...

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 ...

; ''S. minutum'' 4.0 cm (1.6 in) SL and ''S. operculatum'' 8.0 cm (3.1 in). ''S. minutum'' and '' S. operculatum'' usually live in a freshwater, tropical environment. '' S. operculatum'' are harmless to humans.

''Scleronema angustirostre''

As of 2017, ''S. angustirostre'' has been deemed a prohibited nonnative species in Florida, meaning the species is a danger to the ecology, health, and/or welfare of Florida and its residents. Like other species of Scleronema, ''S. angustirostre'' thrive in a freshwater environment and are benthopelagic, meaning that they either live at the surface or bottom of a body of water.

References

Trichomycteridae Fish of South America Fish of Brazil Fish of Uruguay Catfish genera Freshwater fish genera Taxa named by Carl H. Eigenmann {{Trichomycteridae-stub