The Bearn beaked dace (''Leuciscus bearnensis'') is a species 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 ...

. This species has been recorded from several localities in the

Adour The Adour (; ; ) is a river in southwestern France. It rises in High- Bigorre ( Pyrenees), in the commune of Aspin-Aure, and flows into the Atlantic Ocean ( Bay of Biscay) near Bayonne. It is long, of which the uppermost ca. is known as the ' ...

drainage in

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

Taxonomy

The Bearn beaked dace was first formally described as ''Squlaius bearnensis'' in 1866 by the French

zoologist Zoology ( , ) is the scientific study of animals. Its studies include the structure, embryology, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. Zoology is one ...

Émile Blanchard Charles Émile Blanchard (6 March 1819 – 11 February 1900) was a French zoologist and entomologist. Career Blanchard was born in Paris. His father was an artist and naturalist and Émile began natural history very early in life. When he was ...

with its type locality given as Lac de Mouriscot, near

Biarritz Biarritz ( , , , ; also spelled ; ) is a city on the Bay of Biscay, on the Atlantic coast in the Pyrénées-Atlantiques department in the French Basque Country in southwestern France. It is located from the border with Spain. It is a luxu ...

. In the past it was regarded as a

synonym A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

of both the

common dace The common dace (''Leuciscus leuciscus'') is a species of freshwater and brackish water ray-finned fish from the family Leuciscidae which is native to Europe but which has been introduced to other parts of the world. It is a quarry species for co ...

(''L. leuciscus'') and the beaked dace ('' L. burdigalensis''). It is now classified as a valid species in the genus ''

Leuciscus ''Leuciscus'' is a genus of freshwater and brackish water ray-finned fishes belonging to the family Leuciscidae, which includes the daces, Eurasian minnows and related species. They are inland water fishes commonly called Eurasian daces. Th ...

'' 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

Etymology

The Bearn beaked dace is a member of the genus ''Leuciscus'', a name derived tautonymously from the type species' name, '' Cyprinus leuciscus''. ''Leuciscus'' is from the Greek ''leukískos'', a “white mullet” which is a diminutive of ''leukós'', meaning "white", an allusion to the silvery sides of the

. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, ''bearnensis'' , means "of

Béarn Béarn (; ; or ''Biarn''; or ''Biarno''; or ''Bearnia'') is one of the traditional provinces of France, located in the Pyrenees mountains and in the plain at their feet, in Southwestern France. Along with the three Northern Basque Country, ...

, the area of France the type locality is in.

Description

The Bearn beaked dace is distinguished from other western European members of the genus ''

'' by having a keel which runs from its nape to the origin 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 ...

, a projecting snout which has a rounded tip and a projecting upper jaw, the dorsal profile of head and body shows a distinct hump; the snout is 32-35% of the length of the head; and 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 ...

has around 47-52 scales. It also has thick, fleshy lips and a large eye, the diameter of them being approximately a fifth to a quarter of the length of the head. It grows to 280mm in

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 ...

Distribution

The Bearn beaked dave occurs only in the drainage basin of the

in south-western France

Habitat and ecology

The Bearn beaked dace is found in streams, especially in sections of the streams which have clear water and current with cool, deep pools.

References