''Paragenidens'' is a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of sea catfishes containing just one

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

, ''Paragenidens grandoculis''. This species was formerly classified under the genus '' Potamarius'' until a 2019 study found it to be wholly distinct from it. It is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

, where it is known from the

Paraíba do Sul The Paraíba do Sul (), or simply Paraíba, is a river in southeast Brazil. It flows west to northeast from its farthest source at the source of the river Paraitinga to the sea near Campos dos Goytacazes. The river receives its name when it m ...

and the

Doce River The Doce River ( , "Sweet River") is a river in southeast Brazil with a length of . The river basin is economically important. In 2015, the collapse of a dam released highly contaminated water from mining into the river, causing an ecological d ...

s and their mouths. It is highly endangered and was not seen for over 50 years until it was rediscovered during fieldwork for the 2019 study that reclassified it. It is now only known from Lagoa Nova in the municipality of

Linhares Linhares is a Municipalities of Brazil, municipality in the state of Espírito Santo, Brazil, north of the state capital, Vitória, Brazil, Vitória. It is the largest municipality by area in the state, at 9,501.6 km2, and has a population o ...

Espírito Santo Espírito Santo (; ) is a state in southeastern Brazil. Its capital is Vitória, and its largest city is Serra. With an extensive coastline, the state hosts some of the country's main ports, and its beaches are significant tourist attracti ...

state, having been extirpated from its only other recent locality,

Juparanã Lagoon The Juparanã Lagoon is a lagoon located between the municipalities of Linhares, Rio Bananal and Sooretama, in the state of Espírito Santo, Brazil. It is one of the largest lagoons in the country in freshwater volume. The main access is throug ...

in Linhares.

References

{{Taxonbar, from=Q65065322 Catfish genera Ariidae Monotypic fish genera Taxa named by Franz Steindachner Fish described in 1877