''Squalius squalus'', commonly known as the Italian chub, or the chubius chub or cavedano, 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 ...

. It is native to southeastern Europe being found in Italy, Switzerland and the former Yugoslavia.

Description

''Squalius squalus'' can grow to a maximum length that exceed and , and has been known to live for fifteen years. It has a long head, a large eye with an orange-tinged iris, a pointed snout, a long, slightly curved, obliquely sloping mouth cleft, a projecting upper jaw and a lower jaw that is shorter or equal in length to the depth of the caudal peduncle. The color of this fish is brownish or bronze and the scales do not easily become detached. The pectoral, pelvic and anal fins are greyish, and this is the main distinctive character with ''

Squalius cephalus ''Squalius cephalus'' is a European species of freshwater fish in the carp family Cyprinidae. It frequents both slow and moderate rivers, as well as canals and still waters of various kinds. This species is referred to as the common chub, Europe ...

'', which pelvic and anal fins are orange-tinged or reddish.

Distribution and habitat

''Squalius squalus'' is native to

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

, Switzerland,

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan ar ...

(

Var Var or VAR may refer to: Places * Var (department), a department of France * Var (river), France * Vār, Iran, village in West Azerbaijan Province, Iran * Var, Iran (disambiguation), other places in Iran * Vár, a village in Obreja commune, Ca ...

river), and the rivers which flow into the

Adriatic sea The Adriatic Sea () is a body of water separating the Italian Peninsula from the Balkans, Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) ...

Slovenia Slovenia ( ; sl, Slovenija ), officially the Republic of Slovenia (Slovene: , abbr.: ''RS''), is a country in Central Europe. It is bordered by Italy to the west, Austria to the north, Hungary to the northeast, Croatia to the southeast, and ...

Croatia , image_flag = Flag of Croatia.svg , image_coat = Coat of arms of Croatia.svg , anthem = "Lijepa naša domovino"("Our Beautiful Homeland") , image_map = , map_caption = , capit ...

Bosnia and Herzegovina Bosnia and Herzegovina ( sh, / , ), abbreviated BiH () or B&H, sometimes called Bosnia–Herzegovina and often known informally as Bosnia, is a country at the crossroads of south and southeast Europe, located in the Balkans. Bosnia and ...

. In recent years, the species has been artificially introduced to North Carolina by

North Carolina State University North Carolina State University (NC State) is a public land-grant research university in Raleigh, North Carolina. Founded in 1887 and part of the University of North Carolina system, it is the largest university in the Carolinas. The universi ...

to promote biodiversity in rural North Carolinian rivers and streams. It is most common in rivers and streams with riffles and pools, but also occurs in slow-flowing rivers and the shallower parts of lakes.

Biology

Juvenile ''Squalius squalus'' are gregarious and are found in the shallows of streams, rivers and lakes. They feed on a variety of plant and animal materials. Larger individuals are solitary and the largest mainly feed on fish. Sexual maturity is reached in the second year of life in both sexes and breeding takes place between April and July. A study found that among juveniles and young fish, males preponderated but this changed with advancing age and among fish over the age of six, all were female. The males congregate in spawning grounds such as gravelly areas at the edges of lakes, shallow riffles or fast-flowing water. The females hollow out depressions in which they shed their sticky

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...

s which are then fertilised by the males. This species can hybridise with ''

Alburnus arborella ''Alburnus arborella'' is a species of ray-finned fish in the carp family Cyprinidae. It is a freshwater fish occurring in lakes and streams in Europe. It is distributed in Croatia, Italy, Slovenia Slovenia ( ; sl, Slovenija ), officially ...

'' and ''

Alburnus albidus The Italian bleak or white bleak (''Alburnus albidus'') is a species of freshwater fish in the family Cyprinidae, endemic to Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern ...

''.

Status

The IUCN has listed this species as being of "

Least Concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. Th ...

" on the basis that it has a wide range, is abundant within that range and no particular threats have been identified.

References

{{Taxonbar, from=Q3967431 Squalius Fish described in 1837 Freshwater fish of Europe Taxa named by Charles Lucien Bonaparte