Aspidoras is a genus

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...

 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) of the 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...

 Callichthyidae

Callichthyidae

Callichthyidae is a family of catfishes , called armored catfishes due to the two rows of bony plates running down the length of the body. This family contains some of the most popular freshwater aquarium fish, such as the Corydoras.-Taxonomy:The family derives its name from the Greek words kallis...

.

Taxonomy

The type species for this genus is Aspidoras rochai

Aspidoras rochai

Aspidoras rochai is a tropical freshwater fish belonging to the Corydoradinae sub-family of the Callichthyidae family. It originates in inland waters in South America, and is found in coastal rivers in Ceará, Brazil. It was originally described by Hermann von Ihering in 1907.The fish will grow in...

. The name Aspidoras is derived from the Greek

Greek language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 aspis (shield) and dora (skin).

Aspidoras is easily distinguished from the other genera of the subfamily Corydoradinae by the presence of a supraoccipital fontanel; this character is an autapomorphy

Autapomorphy

In cladistics, an autapomorphy is a distinctive anatomical feature, known as a derived trait, that is unique to a given terminal group. That is, it is found only in one member of a clade, but not found in any others or outgroup taxa, not even those most closely related to the group...

 for the genus. Many of the species of Aspidoras are similar and often hard to distinguish. Without specimens, it is often very difficult to positively identify a species from photographs alone.

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 the genus has been demonstrated. Several species of Aspidorasremain to be described.

Distribution

Aspidoras species are endemic to small and shallow streams draining the 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 Shield. The species of Aspidoras are distributed in northeastern and central Brazil, in the states of Ceará

Ceará

Ceará is one of the 27 states of Brazil, located in the northeastern part of the country, on the Atlantic coast. It is currently the 8th largest Brazilian State by population and the 17th by area. It is also one of the main touristic destinations in Brazil. The state capital is the city of...

, Maranhão

Maranhão

Maranhão is a northeastern state of Brazil. To the north lies the Atlantic Ocean. Maranhão is neighbored by the states of Piauí, Tocantins and Pará. The people of Maranhão have a distinctive accent...

, Goiás

Goiás

Goiás is a state of Brazil, located in the central part of the country. The name Goiás comes from the name of an indigenous community...

, Minas Gerais

Minas Gerais

Minas Gerais is one of the 26 states of Brazil, of which it is the second most populous, the third richest, and the fourth largest in area. Minas Gerais is the Brazilian state with the largest number of Presidents of Brazil, the current one, Dilma Rousseff, being one of them. The capital is the...

, Bahia

Bahia

Bahia is one of the 26 states of Brazil, and is located in the northeastern part of the country on the Atlantic coast. It is the fourth most populous Brazilian state after São Paulo, Minas Gerais and Rio de Janeiro, and the fifth-largest in size...

, and Espírito Santo

Espírito Santo

Espírito Santo is one of the states of southeastern Brazil, often referred to by the abbreviation "ES". Its capital is Vitória and the largest city is Vila Velha. The name of the state means literally "holy spirit" after the Holy Ghost of Christianity...

. Most species are narrowly endemic, occurring in restricted areas of some major river drainages: A. lakoi and A. fuscoguttatus from the Paraná River

Paraná River

The Paraná River is a river in south Central South America, running through Brazil, Paraguay and Argentina for some . It is second in length only to the Amazon River among South American rivers. The name Paraná is an abbreviation of the phrase "para rehe onáva", which comes from the Tupi language...

 system, A. albater and A. eurycephalus from the Tocantins River

Tocantins River

The Tocantins is a river in Brazil, the central fluvial artery of the country. In the Tupi language, its name means "toucan's beak" . It runs from south to north for about 2,640 km. It is not really a branch of the Amazon River, although usually so considered, since its waters flow into the...

 system, A. brunneus and A. microgalaeus from the Xingu River

Xingu River

The Xingu River , also called Rio Xingu, is a 1,230-mile long, river in north Brazil; it is a southeast tributary of the Amazon River.-Description and history:...

 system, and A. belenos from Araguaia River

Araguaia River

The Araguaia River or, in Portuguese, Rio Araguaia is one of the major rivers of Brazil, and the principal tributary of the Tocantins. It has a total length of approximately 2,627 km. Araguaia means "river of macaws" in the Tupi language....

 system. Six species are known from northeastern Brazilian coastal river basins: A. rochai from rivers around Fortaleza

Fortaleza

Fortaleza is the state capital of Ceará, located in Northeastern Brazil. With a population close to 2.5 million , Fortaleza is the 5th largest city in Brazil. It has an area of and one of the highest demographic densities in the country...

, A. raimundi from the Parnaíba River

Parnaiba River

The Parnaíba River is a river in Brazil, which forms the border between the states of Maranhão and Piauí. The Parnaíba River rises in the Chapada das Mangabeiras range, and flows northeastward for 1,056 miles to empty into the Atlantic Ocean. The middle and upper regions of this river are...

, A. carvalhoi from rivers around Guaramiranga

Guaramiranga

Guaramiranga is a small town in the Northeastern state of Ceará in Brazil.It is located at an altitude of 835 m in the Serra de Baturité hills 110 km from the state capital of Fortaleza. Guaramiranga is known locally for its temperate climate and lush green scenery...

, Ceará State, A. maculosus from the Itapicuru River

Itapicuru River

The Itapicuru River is a river in Bahia state of eastern Brazil. The Itapicuru rises in the northern part of the state, and flows east to empty into the Atlantic Ocean....

, A. menezesi from the Jaguaribe River

Jaguaribe River

The Jaguaribe River is a highly seasonal river in Ceará state of northeastern Brazil. Two large dams were constructed across the Jaguaribe, the Orós Dam, completed in 1960, and the Castanhão Dam, completed in 2003. The Castanhão Dam flooded the city of Jaguaribara, which was rebuilt nearby as the...

, and A. spilotus from the Acaráu River

Acaraú River

-References:*...

. A. depinnai, is from the Ipojuca River

Ipojuca River

-References:*...

 basin, Pernambuco State. A. taurus is known from the upper Itiquira River

Itiquira River

-References:*...

 and upper Taquari River, both tributaries of the Paraguay River

Paraguay River

The Paraguay River is a major river in south central South America, running through Brazil, Bolivia, Paraguay, and Argentina...

, Mato Grosso

Mato Grosso

Mato Grosso is one of the states of Brazil, the third largest in area, located in the western part of the country.Neighboring states are Rondônia, Amazonas, Pará, Tocantins, Goiás and Mato Grosso do Sul. It also borders Bolivia to the southwest...

 State, Brazil.

Description

They are all small species. A. taurus is exceptional in that it just surpasses 5 cm in length.

In the aquarium

Aspidoras do fairly well in aquaria under similar conditions as for most Corydoras species. The water conditions that seem best are a pH

PH

In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...

 of 6.8 to 7.0 and a temperature of about 22°C to 26°C. The species that is most likely to be found in an aquarium is the sixray corydoras, Aspidoras pauciradiatus.