The Doradidae are a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

catfish Catfish (or catfishes; order (biology), order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Catfish are common name, named for their prominent barbel (anatomy), barbels, which resemble a cat's whiskers, though not ...

es also known as thorny catfishes, raphael catfishes or talking catfishes. These fish are native to

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

, primarily the

Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its tributary, tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries ...

and

the Guianas The Guianas, also spelled Guyanas or Guayanas, are a geographical region in north-eastern South America. Strictly, the term refers to the three Guianas: Guyana, Suriname, and French Guiana, formerly British, Dutch, and French Guiana respectiv ...

. Doradids are

omnivorous An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize ...

Taxonomy

As of 2007, 31

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

and 78

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), ...

are in this family. '' Wertheimeria'' is considered to be the

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

to all other doradids. This family is

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

and contains the subfamilies Doradinae, Astrodoradinae and Wertheimerinae. The Astrodoradinae contain the genera '' Amblydoras'', '' Anadoras'', '' Astrodoras'', '' Hypodoras'', ''

Merodoras ''Merodoras nheco'' is a species of freshwater ray-finned fish, it is the only species in the genus ''Merodoras'' of the catfish (order (biology), order Siluriformes) family (biology), family Doradidae. Taxonomy ''Merodoras'' and its type specie ...

'', ''

Physopyxis ''Physopyxis'' is a genus of thorny catfishes native to tropical South America. Species There are currently three recognized species in this genus. * '' Physopyxis ananas'' Sousa & Rapp Py-Daniel, 2005 * '' Physopyxis cristata'' Sousa & R ...

'', and '' Scorpiodoras''.

Distribution

Doradids occur in most

n basins, though they are absent from the

Pacific Coast Pacific coast may be used to reference any coastline that borders the Pacific Ocean. Geography Americas North America Countries on the western side of North America have a Pacific coast as their western or south-western border. One of th ...

drainages and from coastal drainages south of the

Río de la Plata The Río de la Plata (; ), also called the River Plate or La Plata River in English, is the estuary formed by the confluence of the Uruguay River and the Paraná River at Punta Gorda, Colonia, Punta Gorda. It empties into the Atlantic Ocean and ...

. About 70% of the valid species occur in the

Amazon Amazon most often refers to: * Amazon River, in South America * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon (company), an American multinational technology company * Amazons, a tribe of female warriors in Greek myth ...

basin; the

Orinoco The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers approximately 1 million km2, with 65% of it in Venezuela and 35% in Colombia. It is the List of rivers by discharge, f ...

basin harbors about 22 species and ranks second in species richness. Conversely, only two species of doradids have been described from

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 ...

ian eastern coastal basins: '' Wertheimeria maculata'' from the Jequitinhonha and Pardo rivers and '' Kalyptodoras bahiensis'' from the

Paraguaçu River The Paraguaçu River () is a river in Bahia state, located in eastern Brazil. It runs from the Chapada Diamantina highlands of central Bahia to its mouth at the Baía de Todos os Santos. The Paraguaçu River is the largest river entirely within B ...

Appearance and anatomy

Doradids are easily recognized by a well-developed

nuchal The nape is the back of the neck. In technical anatomical/medical terminology, the nape is also called the nucha (from the Medieval Latin rendering of the Arabic , ). The corresponding adjective is ''nuchal'', as in the term ''nuchal rigidity' ...

shield in front of the

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

, as well as well-developed bony lumps along the

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelia ...

that form thorny scutes. Also, doradids typically 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 cyprini ...

s (no nasal barbels), an

adipose fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only b ...

, and four to six rays on the dorsal fin with a spine on the

anterior Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

(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 SL in '' Physopyxis lyra'' to FL and in '' Oxydoras niger''.

References

External links

The Family Doradidae or "Talking Catfishes"
Article on Scotcat.com by Chris Ralph {{Authority control Catfish of South America Catfish families Taxa named by Pieter Bleeker

Taxonomy

Distribution

Appearance and anatomy

See also

References

External links