The Pimelodidae, commonly known as the long-whiskered catfishes, are a

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 ...

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, ...

es ( order Siluriformes).

Taxonomy

The family Pimelodidae has undergone much revision. Currently, it contains about 30

genera 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 nomenclat ...

and about 90 recognized and known but unnamed species. Wikipedia lists 109 species in this family. The low-eye catfish (previously family Hypophthalmidae), and thus the genus '' Hypophthalmus'', which contains four species, was reclassified with the pimelodids. This family previously included fish that are now classified under Pseudopimelodidae (previously subfamily Pseudopimelodinae) and

Heptapteridae The Heptapteridae, or three-barbeled catfishes, are a family of catfish that originate from the Americas. Most species are restricted to South America, but ''Imparfinis lineatus'', '' Nemuroglanis panamensis'' and ''Pimelodella chagresi'' are na ...

(previously subfamily Rhamdiinae). This family also previously included '' Conorhynchos conirostris'', currently ''

incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

''. However, a molecular analysis has shown unequivocal support for

monophyly In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...

of the individual families and the genus ''Conorhynchos'' into a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

called Pimelodoidea, including Pimelodidae + Pseudopimelodidae and Heptapteridae + ''Conorhynchos''. Some genera have relatively recently been synonymized. ''Merodontotus'' and ''Goslinia'' are now both included under ''

Brachyplatystoma ''Brachyplatystoma'' is a genus of catfish from the family Pimelodidae. As the occasionally used common name goliath catfishes indicates, this genus includes some of the largest species of catfish, including the piraíba, ''B. filamentosum'', whi ...

''. Also, ''Paulicea'' is now a synonym of ''

Zungaro ''Zungaro'' is a genus of long-whiskered catfishes native to South America, with two recognized species : * ' (Hermann von Ihering, H. von Ihering, 1898) * ''Zungaro zungaro'' (Alexander von Humboldt, Humboldt, 1821) (gilded catfish) References< ...

''. The six main groups within Pimelodidae are ''

Steindachneridion ''Steindachneridion'' is a genus of South American pimelodid catfish ( order Siluriformes). Taxonomy The first species of the genus, ''S. parahybae'', was described in 1877 by Franz Steindachner under the name ''Platystoma parahybae''. Later, ...

'', the ''

Phractocephalus The redtail catfish, ''Phractocephalus hemioliopterus'', is a pimelodid (long-whiskered) catfish. In Venezuela, it is known as cajaro, and in Brazil, it is known as pirarara, stemming from the Tupi language words ''pirá'' and ''arara''. It i ...

''-''

Leiarius ''Leiarius'' is a genus of long-whiskered catfishes native to South America. Most of the genus' species are found in the aquarium hobby as ornamental fish. Species There are currently four recognized species in this genus: * '' Leiarius arekaim ...

'' group, the ''

Pimelodus ''Pimelodus'' is a genus of fish in the family (biology), family Pimelodidae native to Central America, Central and South America. Species There are currently 33 recognized species in this genus: * ''Pimelodus absconditus'' María de las Mercede ...

'' group, the '' Calophysus'' group, ''

'', and the ''

Sorubim ''Sorubim'' is a small genus of long-whiskered catfish native to tropical South America. A number of characteristics allows the differentiation of each species in the genus. ''Sorubim'' species are important food fish in South America and are hig ...

'' group. The ''Pimelodus'' group includes ''Pimelodus'', '' Exallodontus'', ''

Duopalatinus ''Duopalatinus'' is a small genus of long-whiskered catfishes native to South America. Species There are currently two recognized species in this genus: * '' Duopalatinus emarginatus'' (Valenciennes, 1840) * '' Duopalatinus peruanus'' Eigenmann ...

'', '' Cheirocerus'', '' Iheringichthys'', '' Bergiaria'', '' Bagropsis'', '' Parapimelodus'', ''

Platysilurus ''Platysilurus'' is a genus of long-whiskered catfishes native to South America. Taxonomy ''Platysilurus'' is classified under the "'' Calophysus-Pimelodus'' clade". Within this clade, it is considered a part of the "Pimelodus-group" of Pimelo ...

'', ''

Platystomatichthys ''Platystomatichthys sturio'' is the only species in the genus ''Platystomatichthys'' of the catfish ( order Siluriformes) family Pimelodidae. It is sometimes called the sturgeon catfish. This species occurs in the Amazon Basin and reaches a len ...

'', and ''

Propimelodus ''Propimelodus'' is a genus of South American catfish of the family Pimelodidae. Taxonomy The type species of this genus, ''P. eigenmanni'', was first described in 1946 under the genus ''Pimelodus''. In 2002, the genus ''Propimelodus'' was descr ...

''. The ''Calophysus'' group includes the five genera '' Aguarunichthys'', '' Pimelodina'', ''Calophysus'', '' Luciopimelodus'', and ''

Pinirampus ''Pinirampus pirinampu'' is a species of catfish ( order Siluriformes) of the family Pimelodidae. ''P. pirinampu'' is also known as the flatwhiskered catfish. Taxonomy This species was first described as ''Pimelodus barbancho''; however, this is ...

''. The relationships within each genus are still being studied. Most genera lack a hypothesis for

Distribution

All species of Pimelodidae are found 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 southe ...

and the lower Isthmian region. Their range reaches from South America and

Panama Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Cos ...

north to southernmost

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

Description

Many long-whiskered catfishes grow to be very large, including the piraiba, ''Brachyplatystoma filamentosum'', reaching about 3 m in length. They have three pairs of

barbel Barbel may refer to: *Barbel (anatomy), a whisker-like organ near the mouth found in some fish (notably catfish, loaches and cyprinids) and turtles *Barbel (fish), a common name for certain species of fish **''Barbus barbus'', a species of cyprinid ...

s, with maxillary barbels that may reach the length of the fish's body. Like many other catfishes, their bodies lack scales. The adipose fin is well developed. Many species of Pimelodidae have juvenile forms that appear differently from their adult forms in color pattern, as well as body shape. ''Brachyplatystoma'' species have specialized pelagic young with greatly elongated barbels and fin filaments, and strongly ornamented pectoral spines. Other large pimelodids, such as ''Pseudoplatystoma'', ''Sorubim'', and ''Sorubimichthys'', whose young inhabit vegetated, marginal waters, have distinctive cryptic coloration patterns and much enlarged caudal and pectoral fins.

Ecology

They are generally bottom-living fish, though some are pelagic and probably filter-feeders. They do not guard their young.

Relationship to humans

Because of their large size in many species, pimelodids are an important food fish in South America. Many species have been hybridized through the use of

hormones A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and beh ...

in an effort to get even larger fish. This same size factor also makes them very popular for

sport fishing Recreational fishing, also called sport fishing or game fishing, is fishing for leisure, exercise or competition. It can be contrasted with commercial fishing, which is professional fishing for profit (economics), profit; or subsistence fishing ...

. Pimelodids are a common addition to Amazonian-themed exhibits in

zoo A zoo (short for zoological garden; also called an animal park or menagerie) is a facility in which animals are kept within enclosures for public exhibition and often bred for conservation purposes. The term ''zoological garden'' refers to zoo ...

s and

public aquaria A public aquarium (plural: ''public aquaria'' or ''public Water Zoo'') is the aquatic counterpart of a zoo, which houses living aquatic animal and plant specimens for public viewing. Most public aquariums feature tanks larger than those kept b ...

. Despite the looming danger of size in many species, pimelodids remain a popular home

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. Controversy exists over whether or not many of the larger species should be sold in the hobby because of their adult size. Also, some disagreement occurs over hybrids appearing in the hobby, as well. Many species are hardy and easy to take care of. However, care should have course be taken on what other fish to house pimelodids with, as they do not hesitate to eat other fish that are small enough.

References