Doradidae
Encyclopedia
Doradidae is a family
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 also known as thorny catfishes or talking catfishes. These fish are native to South America
South 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...

, primarily in Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

, Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

, and the Guianas.

Doradids are omnivorous
Omnivore
Omnivores are species that eat both plants and animals as their primary food source...

.

Taxonomy

As of 2007, there are 31 genera
Genus
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 78 species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 in this family. Wertheimeria is considered to be the sister taxon
Cladistics
Cladistics is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants . For example, birds, dinosaurs, crocodiles, and all descendants of their most recent common ancestor form a clade...

 to all other doradids. This family is monophyletic
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...

 and contains the subfamilies Platydoradinae, Doradinae, and Astrodoradinae, though their relationships are mostly unresolved. Astrodoradinae contains the genera Amblydoras
Amblydoras
Amblydoras is a genus of catfishes of the family Doradidae. This genus includes, A. affinis, A. bolivarensis, A. gonzalezi, A. monitor, and A. nauticus....

, Anadoras
Anadoras
Anadoras is a genus of catfishes of the family Doradidae. There are three species A. grypus, A. regani, and A. weddellii. This genus belongs in the subfamily Astrodoradinae....

, Astrodoras, Hypodoras, Merodoras, Physopyxis
Physopyxis
Physopyxis is a genus of catfishes of the family Doradidae. It includes three species, P. ananas, P. cristata, and P. lyra.-Distribution:P...

, and Scorpiodoras.

Distribution

Doradids occur in most South America
South 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...

n basins, though they are absent from the Pacific coast
Pacific Coast
A country's Pacific coast is the part of its coast bordering the Pacific Ocean.-The Americas:Countries on the western side of the Americas have a Pacific coast as their western border.* Geography of Canada* Geography of Chile* Geography of Colombia...

 drainages and from coastal drainages south of the Río de la Plata
Río de la Plata
The Río de la Plata —sometimes rendered River Plate in British English and the Commonwealth, and occasionally rendered [La] Plata River in other English-speaking countries—is the river and estuary formed by the confluence of the Uruguay River and the Paraná River on the border between Argentina and...

. 70% of the valid species occur in the Amazon
Amazon River
The Amazon of South America is the second longest river in the world and by far the largest by waterflow with an average discharge greater than the next seven largest rivers combined...

 basin; the Orinoco basin harbors about 22 species and ranks second in species richness. On the other hand, only two species of doradids have been described from Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

ian eastern coastal basins: Wertheimeria maculata
Wertheimeria maculata
Wertheimeria maculata is the only species in the genus Wertheimeria of the catfish family Doradidae. This species originates from the Jequitinhonha and Pardo Rivers. These fish reach a length of about 30 centimetres . Within its restricted range, W...

from the Jequitinhonha
Jequitinhonha River
thumb|Source of the river in [[Serro]]|rightThe Jequitinhonha River is a river that flows mainly through the Brazilian state of Minas Gerais. Its source lies near Diamantina in the Serra do Espinhaço at an elevation of 1,200 m, after which it flows northward and then east-northeastward across the...

 and Pardo river
Rio Pardo (river)
Rio Pardo is a small river near Jaborandi in the Brazilian state of São Paulo....

s and Kalyptodoras bahiensis
Kalyptodoras bahiensis
Kalyptodoras bahiensis is the only species in the genus Kalyptodoras of the catfish family Doradidae. This species originates from the Paraguaçu River in northeastern Brazil and reaches a length of about 25 centimetres ....

from the Paraguaçu River
Paraguaçu River
The Paraguaçu River is a river in Bahia state of eastern Brazil. It originates in the Chapada Diamantina highlands of central Bahia following the chain of mountains called Sincura, and flows east 500 km to empty into the Baía de Todos os Santos....

.

Appearance and anatomy

Doradids are easily recognized by a well-developed nuchal
Nape
The nape is the back of the neck. In technical anatomical/medical terminology, the nape is referred to by the word nucha, which also gives the adjective corresponding to "nape" in English, "nuchal"....

 shield in front of the dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...

 as well as well-developed bony lumps along the lateral line
Lateral line
The lateral line is a sense organ in aquatic organisms , used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail...

 that form thorny scutes. Also, doradids typically have three pairs of barbel
Barbel (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 (no nasal barbels), an adipose fin, and 4–6 rays on the dorsal fin with a spine on the anterior (first) ray. These fish are sometimes called "talking catfish" because of their ability to produce sound by moving their pectoral spine or vibrating their swim bladder. Sizes range from 3.5 centimetres (1.4 in) SL
Fish measurement
Fish measurement refers to the measuring of the length of individual fish and of various parts of their anatomy. These data are used in many areas of ichthyology, including taxonomy and fisheries biology.-Overall length:...

 in Physopyxis lyra
Physopyxis
Physopyxis is a genus of catfishes of the family Doradidae. It includes three species, P. ananas, P. cristata, and P. lyra.-Distribution:P...

to 120 centimetres (47.2 in)
FL
Fish measurement
Fish measurement refers to the measuring of the length of individual fish and of various parts of their anatomy. These data are used in many areas of ichthyology, including taxonomy and fisheries biology.-Overall length:...

 and 20 kilograms (44.1 lb) in Oxydoras niger
Oxydoras niger
The ripsaw catfish is a species of catfish of the family Doradidae. It is native to the tropical river basins of South America.-In the aquarium:...

.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK