''Pseudochondrostoma'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of freshwater

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

belonging to the

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 ...

Leuciscidae Leuciscidae is a family of freshwater ray-finned fishes, formerly classified as a subfamily of the Cyprinidae, which contains the true minnows. Members of the Old World (OW) clade of minnows within this subfamily are known as European minnow ...

, which includes the daces, Eurasian minnows and related species. The fishes in this genus occur in the

Iberian Peninsula The Iberian Peninsula ( ), also known as Iberia, is a peninsula in south-western Europe. Mostly separated from the rest of the European landmass by the Pyrenees, it includes the territories of peninsular Spain and Continental Portugal, comprisin ...

. They are commonly known as the straight-mouth nases.

Taxonomy

''Pseudochondrostoma'' was first proposed as a genus in 2007 by Joana Isabel Robalo, Vítor Carvalho Almada, André Levy Coelho and

Ignacio Doadrio Villarejo Ignacio is a male Spanish name originating in the Latin name "Ignatius" from ''ignis'' "fire". This was the name of several saints, including the third bishop of Antioch (who was thrown to wild beasts by emperor Trajan) and Saint Ignatius of Lo ...

with ''Chondrostoma polylepis'' designated as the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

. ''C. polylepis'' was first formally described in 1864 by the Austrian

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 35,800 species of fish had been described as of March 2 ...

Franz Steindachner Franz Steindachner (11 November 1834 in Vienna – 10 December 1919 in Vienna) was an Austrian zoologist, ichthyologist, and herpetologist. He published over 200 papers on fishes and over 50 papers on reptiles and amphibians. Steindachner des ...

with its type locality given as Crato, Portugal. Robalo ''et al'' proposed the genus ''Pseudochondrostoma'' when they reviewed the genus '' Chondrostoma'' and found that in the north and central Mediterranean the taxa previoulsy included in ''Chondrostoma'' should be placed in new genera. The authors proposed that these taxa be transferred into the genera '' Achondrostoma'', ''

Iberochondrostoma ''Iberochondrostoma'' is a genus of freshwater Actinopterygii, ray-finned fishes belonging to the Family (biology), family Leuciscidae. The fishes in this genus are Endemism, endemic to the Iberian Peninsula. Species ''Iberochondrostoma'' contain ...

'', ''Pseudochondrostoma'', '' Protochondrostoma'' and '' Parachondrostoma''. The genus ''Pseudochondrostoma'' is classified within the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

Leuciscinae Leuciscinae is a subfamily of freshwater Actinopterygii, ray-finned fishes belonging to the Family (biology), family Leuciscidae, which includes the fishes known as daces, chubs, shiners and minnows. The fishes in this subfamily are mainly found i ...

of the family Leuciscidae.

Species

''Pseudochondrostoma'' contains the following species: * '' Pseudochondrostoma duriense'' ( M. M. Coelho, 1985) (Northern straight-mouth nase) * '' Pseudochondrostoma polylepis'' (Steindachner, 1864) (Iberian nase) * '' Pseudochondrostoma willkommii'' (Steindachner, 1866) (Southern straight-mouth nase)

Etymology

''Pseudchondrostoma'' prefixes ''Chondrostoma'' with ''pseudo-'' which means "false", applied because although the fishes in this genus are similar in appearance to the nases in the genus ''Chondrostoma'' such similarities are due to

convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last comm ...

rather than common ancestry, and are therefore "false".

Characteristics

''Pseudchondrostoma'' nases have a straight, rather than arched mouth, which has a horny layer in the lower lip. They have between 59 and 78 pored scales in 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 ...

, there are between 10 and 12 scales above the lateral line with 4 to 6 scales below it. The

anal 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 o ...

has between 8 and 10 branched rays with 8 or 9 branched rays in 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 ...

. These fishes all have maximum

standard length Fish measurement is the measuring of individual fish and various parts of fish anatomy, their anatomies, for data used in many areas of ichthyology, including Taxonomy (biology), taxonomy and fishery biology. Overall length Standard length (SL) is ...

of .

Distribution

''Pseudchondrostoma'' nases are endemic to the rivers on the Atlantic coastal slope if the Iberian Peninsula.

References

Leuciscinae Fish of Europe Taxa named by Ignacio Doadrio Villarejo {{Leuciscinae-stub