Sisoroidea is a superfamily 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). It contains the four families

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...

 Amblycipitidae

Amblycipitidae

Amblycipitidae is a family of catfishes, commonly known as torrent catfishes. It includes three genera, Amblyceps, Liobagrus, and Xiurenbagrus.-Taxonomy:...

, Akysidae, Sisoridae

Sisoridae

Sisoridae is a family of catfishes . These Asian catfish live in fast-moving waters and often have adaptations that allow them to adhere to objects in their habitat.-Taxonomy:...

, and Erethistidae

Erethistidae

Erethistidae are a family of catfishes that originate from southern Asia.-Taxonomy:This family includes species previously placed in Sisoridae. They were removed because they were thought to be more closely related to the neotropical Aspredinidae than to the remaining sisorids due to a number of...

; many sources also include Aspredinidae

Aspredinidae

The Aspredinidae are a small South American family of catfishes also known as the banjo catfishes.-Distribution:Aspredinids are found throughout the major tropical rivers of South America...

. With Aspredinidae, this superfamily includes about 42 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 230 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...

.

Taxonomy

Sisoroidea is sister

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 the Loricarioidea

Loricarioidea

Loricarioidea is a superfamily of catfishes . It contains the six families Trichomycteridae, Nematogenyiidae, Callichthyidae, Scoloplacidae, Astroblepidae, and Loricariidae. Some schemes also include Amphiliidae...

. The 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 this superfamily is supported by a number of morphological

Morphology (biology)

In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....

 characters. Amblycipitidae is the most basal

Basal (phylogenetics)

In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...

 family and is sister to the remaining families. Based on morphological data, Erethistidae is the sister group to Aspredinidae, with Sisoridae being the sister group of the 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...

 formed by these two families. However, it has been proposed to move the erethistid genera back into Sisoridae. Also, some authors have removed Aspredinidae from Sisoroidea, having found it to be more closely related to Doradoidea (Doradidae, Auchenipteridae, and possibly Mochokidae) with morphological and molecular evidence.

Distribution

Sisoroidea includes almost exclusively Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

tic catfish families with the exception of Aspredinidae

Aspredinidae

The Aspredinidae are a small South American family of catfishes also known as the banjo catfishes.-Distribution:Aspredinids are found throughout the major tropical rivers of South America...

, which is 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...

.