''Squalius valentinus'', commonly known as the Valencia chub and the Levantine bagra, is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

of freshwater fish in the carp

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Cyprinidae Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest v ...

.Doadrio, Ignacio, and Jose A. Carmona. "Phylogenetic overview of the genus Squalius (Actinopterygii, Cyprinidae) in the Iberian Peninsula, with description of two new species." Cybium 30.3 (2006): 199-214. It was first isolated from the

Turia River The Turia or Túria ( ca-valencia, Riu Túria ; es, link=no, Río Turia ; la, Tūria) is a river in Spain, which has its source in the Montes Universales in the mountain ranges of the northwesternmost end of the Sistema Ibérico, Teruel pro ...

Valencia Valencia ( va, València) is the capital of the autonomous community of Valencia and the third-most populated municipality in Spain, with 791,413 inhabitants. It is also the capital of the province of the same name. The wider urban area al ...

, hence its name. It is considered endangered. This species is differentiated from its cogenerates by having eight branched rays in its

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...

; eight branched rays in its

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as s ...

; two rows of

pharyngeal teeth Pharyngeal teeth are teeth in the pharyngeal arch of the throat of cyprinids, suckers, and a number of other fish species otherwise lacking teeth.

on both sides possessing 2 and 5 teeth (); a wide caudal peduncle; its number of

gill raker Gill rakers in fish are bony or cartilaginous processes that project from the branchial arch (gill arch) and are involved with suspension feeding tiny prey. They are not to be confused with the gill filaments that compose the fleshy part of th ...

s; the number of

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number ...

in its lateral line; the number of scale rows above the latter; by possessing three scale rows below it; by having thirty-nine

vertebrae The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristi ...

(twenty-two of them abdominal and seventeen of them caudal); showing large 4th and 5th infraorbital bones; a

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The ...

with a very distinct marked anterior process; exhibiting a

frontal bone The frontal bone is a bone in the human skull. The bone consists of two portions.'' Gray's Anatomy'' (1918) These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bony part of the forehead, pa ...

expanded at the middle; a wide

neurocranium In human anatomy, the neurocranium, also known as the braincase, brainpan, or brain-pan is the upper and back part of the skull, which forms a protective case around the brain. In the human skull, the neurocranium includes the calvaria or sk ...

bone; the lower branch of the pharyngeal bone being robust; a large and narrow urohyal; as well as genetic differences (

allozymes Alloenzymes (or also called allozymes) are variant forms of an enzyme which differ structurally but not functionally from other allozymes coded for by different alleles at the same locus. These are opposed to isozymes, which are enzymes that perfo ...

Description

''Squalius valentinus'' is a small sized species that is usually shorter than ; its head is large and similar to the maximum body depth. Its preorbital distance is similar to its eye's diameter, exhibiting a long interorbital distance. Its

ventral fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous Homology may refer to: Sciences Biology *Homology (biology), any characteristic of biological organisms that is der ...

is inserted at the origin of the dorsal fin, on its same

axis An axis (plural ''axes'') is an imaginary line around which an object rotates or is symmetrical. Axis may also refer to: Mathematics * Axis of rotation: see rotation around a fixed axis * Axis (mathematics), a designator for a Cartesian-coordinat ...

. Its predorsal length is somewhat larger than its preventral length. It possesses a high caudal

peduncle Peduncle may refer to: *Peduncle (botany), a stalk supporting an inflorescence, which is the part of the shoot of seed plants where flowers are formed *Peduncle (anatomy), a stem, through which a mass of tissue is attached to a body **Peduncle (art ...

. It shows a large fin size, with a

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

that is larger than the height of its dorsal fin.

Pigmentation

Its body is silver, somewhat darker dorsally; its scales have a big black spot at their base and several small black spots on its distal border. Its peritoneum also carries small black spots. Its scales are

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, a ...

in juveniles.

Osteology

It possesses a wide and short supraethmoid, parietal and

s. The posterior process of its pterotic bone is wide and robust, while the pharyngeal bone's lower branch is very robust. Its urohyal bone is large and thin. The maxilla's anterior process is pointed, and its 4th and 5th infraorbital bones are very wide. The posterior lamina of its

cleithrum The cleithrum (plural cleithra) is a membrane bone which first appears as part of the skeleton in primitive bony fish, where it runs vertically along the scapula. Its name is derived from Greek κλειθρον = "key (lock)", by analogy with " cl ...

is widened. It shows a short maxilla with a relatively developed coronoid process. Itd 3rd, 4th and 5th pharyngeal teeth in its external row are small or even lack a masticatory area.

Distribution and habitat

''Squalius valentinus'' inhabits rivers in the Spanish

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on th ...

, between the

Mijares Mijares is a municipality located in the province of Ávila, Castile and León, Spain. According to the 2004 census (INE INE, Ine or ine may refer to: Institutions * Institut für Nukleare Entsorgung, a German nuclear research center * Insti ...

and

Vinalopó The Vinalopó is a small river flowing through the Alicante province, of Spain. It flows from north to south and, with a length of 81 km., it is the longest of the rivers which flows for its entire length within the limits of this province. ...

basins Basin may refer to: Geography and geology * Depression (geology) ** Back-arc basin, a submarine feature associated with island arcs and subduction zones ** Debris basin, designed to prevent damage from debris flow ** Drainage basin (hydrology), ...

. The

Júcar left The Júcar () or Xúquer () is a river on the Iberian Peninsula of Spain. The river runs for approximately 509 km from its source at Ojuelos de Valdeminguete, on the eastern flank of the Montes Universales, Sistema Ibérico. Its most i ...

basin is inhabited by both this species and '' S. pyrenaicus'', although both species are

allopatric Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from ...

, the latter inhabiting the upper basin while former is distributed throughout rivers of the lower basin. The species usually is found to inhabit streams with clear waters and gravel bottoms. In streams such as the Gorgos River it is the only

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...

fish. In the Turia and Mijares basins it occurs in

sympatry In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species s ...

with other native cyprinids: '' Barbus guiraonis'', '' Chondrostoma turiense'' and '' Chondrostoma arcasii''. ''S. valentinus'' inhabits the Júcar,

Serpis The Serpis () is a short coastal river in the provinces of Alicante and Valencia, in Spain. The river starts at the feet of the Carrasqueta, a mountain area southwest to Alcoi, by the confluence of the Polop and Troncal streams. In its initial pa ...

and Vinalopó basins along with ''B. guiraonis''.

Status

The IUCN lists this fish as being a

vulnerable species A vulnerable species is a species which has been categorized by the International Union for Conservation of Nature as being threatened with extinction unless the circumstances that are threatening its survival and reproduction improve. Vulne ...

because of its limited range which covers less than , and due to

water abstraction Water extraction (or water withdrawal) is the process of taking water from any source, either temporarily or permanently, for flood control or to obtain water for, for example, irrigation. The extracted water could also be used as drinking wate ...

for the construction of dams as well as the introduction of foreign species. It is a rare species and has a restricted distribution range. The population is currently declining. ''S. valentinus'' is frequently dominant as a species in small rivers, however in wide rivers the species is local and rare.

References

External links

*
FishBase
{{DEFAULTSORT:Squalius valentinus Squalius Fauna of Spain Freshwater fish of Europe Taxa named by Ignacio Doadrio Villarejo Taxa named by José Ambrosio González-Carmona Fish described in 2006