Pimelodidae
Encyclopedia
Pimelodidae, commonly known as the long-whiskered catfishes, is a family
of catfish
es (order
Siluriformes).
and about 90 recognized and known but unnamed species. 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
(previously subfamily Rhamdiinae). This family also previously included Conorhynchos conirostris
, currently incertae sedis
. However, a molecular analysis has shown unequivocal support for monophyly
of the individual families and the genus Conorhynchos into a clade
called Pimelodoidea, including Pimelodidae + Pseudopimelodidae and Heptapteridae + Conorhynchos.
Some genera have relatively recently been synonymized
. Merodontotus and Goslinia are now both included under Brachyplatystoma
. Also, Paulicea is now a synonym of Zungaro.
There are six main groups within Pimelodidae; these are Steindachneridion
, the Phractocephalus-Leiarius
group, the Pimelodus
group, the Calophysus group, Zungaro, and the Sorubim
group. The Pimelodus group includes Pimelodus, Exallodontus, Duopalatinus
, Cheirocerus
, Iheringichthys
, Bergiaria
, Bagropsis, Parapimelodus
, Platysilurus
, Platystomatichthys, and Propimelodus
. The Calophysus group includes the five genera Aguarunichthys
, Pimelodina, Calophysus, Luciopimelodus, and Pinirampus.
The relationships within each genus are still being studied. Most genera lack a hypothesis for monophyly
.
and the lower Isthmian region. Their range reaches from South America and Panama
north to southernmost Mexico
.
s, with maxillary barbels that may reach the length of the fish's body. Like many other catfish, their bodies lack scales. The adipose fin is well developed.
Many species of Pimelodidae have juvenile forms that appear different from their adult forms in color pattern as well as body shape. Brachyplatystoma 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.
Pimelodids are a common addition to Amazonian-themed exhibits in zoo
s and public aquaria
.
Despite the looming danger of size in many species, Pimelodids remain a popular home aquarium
fish. Controversy exists over whether or not many of the larger Pimelodid species should be sold in the hobby because of their large adult size. Also, there is some disagreement over hybrids appearing in the hobby as well. Many species are hardy and easy to take care of. However, care should of course be taken on what other fish to house Pimelodids with, as they won't hesitate to eat other fish that are small enough.
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of catfish
Catfish
Catfishes 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 heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...
es (order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Siluriformes).
Taxonomy
Pimelodidae has undergone much revision. Currently, the family contains about 30 generaGenus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
and about 90 recognized and known but unnamed species. The low-eye catfish (previously family Hypophthalmidae), and thus the genus Hypophthalmus
Hypophthalmus
Hypophthalmus is a genus of catfishes of the family Pimelodidae. It includes four species, H. edentatus, H. fimbriatus, H. marginatus, and H. oremaculatus.-Taxonomy:...
which contains four species, was reclassified with the Pimelodids.
This family previously included fish that are now classified under Pseudopimelodidae
Pseudopimelodidae
Pseudopimelodidae is a small family of catfishes. Some of these fish are popular aquarium fish.-Taxonomy:This family was formerly a subfamily of Pimelodidae. Pseudopimelodidae is a monophyletic group. Previously, the superfamily Pseudopimelodoidea is sister to superfamilies Sisoroidea + Loricarioidea...
(previously subfamily Pseudopimelodinae) and Heptapteridae
Heptapteridae
Heptapteridae is a family of catfish that originate from Mexico to South America. Heptapteridae is derived from Greek, hepta meaning seven and pteron meaning fin....
(previously subfamily Rhamdiinae). This family also previously included Conorhynchos conirostris
Conorhynchos conirostris
Conorhynchos conirostris is a species of catfish .The spelling of the generic name has been confused; it is currently valid as Conorhynchos as described by Pieter Bleeker in 1858. This catfish has unknown relationships. It does not appear to be assignable to any family and is placed incertae sedis...
, currently incertae sedis
Incertae sedis
, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...
. However, a molecular analysis has shown unequivocal support for monophyly
Monophyly
In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it contains all the descendants of the possibly hypothetical closest common ancestor of the members of the group. The term is synonymous with the uncommon term holophyly...
of the individual families and the genus Conorhynchos into a clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
called Pimelodoidea, including Pimelodidae + Pseudopimelodidae and Heptapteridae + Conorhynchos.
Some genera have relatively recently been synonymized
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
. Merodontotus and Goslinia are now both included under Brachyplatystoma
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, which reaches about in length...
. Also, Paulicea is now a synonym of Zungaro.
There are six main groups within Pimelodidae; these are Steindachneridion
Steindachneridion
Steindachneridion is a genus of South American Pimelodid catfish .-Taxonomy:The first species of the genus, S. parahybae, was described in 1877 by Franz Steindachner under the name Platystoma parahybae. Later, Carl H. Eigenmann and Rosa Smith Eigenmann described Steindachneridia, named for...
, the Phractocephalus-Leiarius
Leiarius
Leiarius is a genus of catfishes of the family Pimelodidae. It includes four species. Most of the genus' species are ornamental species kept as pets in the aquarium hobby.-Taxonomy:...
group, the Pimelodus
Pimelodus
Pimelodus is a genus of catfishes of the family Pimelodidae.Pimelodus is a non-monophyletic assemblage with about 24 species; it is defined by a set of non-derived characters. Species level taxonomy of Pimelodus is still poorly known as well as the phylogenetic relationships within and of the genus...
group, the Calophysus group, Zungaro, and the Sorubim
Sorubim
Sorubim is a small genus of Pimelodid catfish originating from tropical South America. A number of characteristics allows the differentiation of each species in the genus...
group. The Pimelodus group includes Pimelodus, Exallodontus, Duopalatinus
Duopalatinus
Duopalatinus is a small genus of catfishes of the family Pimelodidae. It contains two species, D. emarginatus and D. peruanas.Duopalatinus is classified under the "Calophysus-Pimelodus clade"...
, Cheirocerus
Cheirocerus
Cheirocerus is a genus of catfishes of the family Pimelodidae. It includes three species, C. abuelo, C. eques, and C. goeldii.-Distribution and habitat:...
, Iheringichthys
Iheringichthys
Iheringichthys is a small genus of catfish of the family Pimelodidae. It includes two species, I. labrosus and I. megalops.-Appearance and anatomy:...
, Bergiaria
Bergiaria
Bergiaria is a small genus of catfishes of the family Pimelodidae. It contains two species, B. platana and B. westermanni....
, Bagropsis, Parapimelodus
Parapimelodus
Parapimelodus is a small genus of catfishes of the family Pimelodidae. It contains two species, P. nigribarbis and P. valenciennis.-Distribution:...
, Platysilurus
Platysilurus
Platysilurus is a genus of catfishes of the family Pimelodidae. This genus contains three species, P. malarmo, P. mucosus, and P. olallae....
, Platystomatichthys, and Propimelodus
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 described for this species. Shortly after, in 2006, the species P. caesius...
. The Calophysus group includes the five genera Aguarunichthys
Aguarunichthys
Aguarunichthys is a genus of catfishes of the family Pimelodidae. It includes species, A. inpai, A. tocantinsensis, and A. torosus.-Etymology:...
, Pimelodina, Calophysus, Luciopimelodus, and Pinirampus.
The relationships within each genus are still being studied. Most genera lack a hypothesis for monophyly
Monophyly
In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it contains all the descendants of the possibly hypothetical closest common ancestor of the members of the group. The term is synonymous with the uncommon term holophyly...
.
Distribution
All species of Pimelodidae are found in South AmericaSouth America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
and the lower Isthmian region. Their range reaches from South America and Panama
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
north to southernmost Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
.
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 barbelBarbel (anatomy)
A barbel on a fish is a slender, whiskerlike tactile organ near the mouth. Fish that have barbels include the catfish, the carp, the goatfish, sturgeon, the zebrafish and some species of shark...
s, with maxillary barbels that may reach the length of the fish's body. Like many other catfish, their bodies lack scales. The adipose fin is well developed.
Many species of Pimelodidae have juvenile forms that appear different from their adult forms in color pattern as well as body shape. Brachyplatystoma 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 in an effort to get even larger fish. This same size factor also makes Pimelodids very popular for sport fishing.Pimelodids are a common addition to Amazonian-themed exhibits in zoo
Zoo
A zoological garden, zoological park, menagerie, or zoo is a facility in which animals are confined within enclosures, displayed to the public, and in which they may also be bred....
s and public aquaria
Public aquarium
A public aquarium is the aquatic counterpart of a zoo, housing living aquatic species for viewing. Most public aquariums feature tanks larger than those kept by home aquarists, as well as smaller tanks. Since the first public aquariums were built in the mid-19th century, they have become popular...
.
Despite the looming danger of size in many species, Pimelodids remain a popular home aquarium
Aquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
fish. Controversy exists over whether or not many of the larger Pimelodid species should be sold in the hobby because of their large adult size. Also, there is some disagreement over hybrids appearing in the hobby as well. Many species are hardy and easy to take care of. However, care should of course be taken on what other fish to house Pimelodids with, as they won't hesitate to eat other fish that are small enough.