The pigoKottelat, M. and J. Freyhof, 2007. Handbook of European freshwater fishes. Publications Kottelat, Cornol, Switzerland. 646 p. (''Rutilus pigus''), or Italian roach, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

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 fishes. This species is found in northern Italy and southern Switzerland.

Taxonomy

The pigo was first formally described as ''Cyprinus pigus'' in 1803 by the French

naturalist Natural history is a domain of inquiry involving organisms, including animals, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history is cal ...

Bernard Germain de Lacépède Bernard-Germain-Étienne de La Ville-sur-Illon, comte de Lacépède or La Cépède (; 26 December 17566 October 1825) was a French natural history, naturalist and an active freemason. He is known for his contribution to the Comte de Buffon's g ...

with its type locality given as

Lake Como Lake Como ( , ) also known as Lario, is a lake of glacial origin in Lombardy, Italy. It has an area of , making it the third-largest lake in Italy, after Lake Garda and Lake Maggiore. At over deep, it is one of the deepest lakes in Europe. ...

Lake Maggiore Lake Maggiore (, ; ; ; ; literally 'greater lake') or Verbano (; ) is a large lake located on the south side of the Alps. It is the second largest lake in Italy and the largest in southern Switzerland. The lake and its shoreline are divided be ...

and other lakes of Italy. This species is now classified within the genus ''

Rutilus ''Rutilus'', commonly known as roaches, is a genus of freshwater ray-finned fish belonging to the family Leuciscidae, which includes the daces, Eurasian minnows and related fishes. This genus is a widely distributed lineage of leuciscids and r ...

'' in 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

. This species was previously considered to be the same species as the cactus roach (''Rutilus virgo''), of the Danube River system. However, molecular analyses published since the late 2000s have shown that these are two separate valid species.

Etymology

The pigo belongs to the genus ''Rutilus'', a name which means "red, golden red and reddish yellow" and is an allusion to the red colour of the fins of the

common roach The roach, or rutilus roach (''Rutilus rutilus''), also known as the common roach, is a fresh- and brackish-water fish of the family Cyprinidae, native to most of Europe and western Asia. Fish called roach can be any species of the genera ''Rut ...

''R. rutilus''), the type species of the genus. 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 ...

, ''pigus'', is a latinisation of the Latinization of the Italian name for this species, ''pigo'' or ''picho''. This name dates to at least 1558 when Hippolito Salviani included it in his ''Aquatilium animalium''. In 1560

Conrad Gessner Conrad Gessner (; ; 26 March 1516 – 13 December 1565) was a Swiss physician, naturalist, bibliographer, and philologist. Born into a poor family in Zürich, Switzerland, his father and teachers quickly realised his talents and supported him t ...

stated that the name is derived from the German ''becken'', meaning "to beat or strike" or ''bicken'', which means "to prick", a reference to the sharp, pointed nuptial tubercles on males.

Description

The pigo is told apart from the other roaches in Italy by having a black

peritoneum The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesotheli ...

and the males having two rows of nuptial tubercles on the side of the head above the eyes. The lower row has between 8 and 11 tubercles, the upper one has 3 to 6. These tubercles on body and head are conical, acutely pointed, forward pointing, and take up around 1/3 of the exposed area of their scale. Additional identification features include having between 43 and 46 scales along 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 branched fin 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 ...

and in 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 ...

, the inferior mouth and laterally compressed body, a silvery iris, the flanks are golden-bronze, marbled with black, and the snout is conical. This species has a 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 , although is more typical, and a maximum weight of .

Distribution and habitat

The pigo is found in the northern basin of the Adriatic Sea in Italy and Switzerland between the Po east to the

Livenza The Livenza (; ; ) is a river in the Italian provinces of Pordenone, Treviso and Venice. Its source is near Polcenigo and Caneva in Pordenone. It flows in a southeasterly direction past Sacile and forms the border between the provinces of Porden ...

, including Lakes Como, Maggiore,

Lugano Lugano ( , , ; ) is a city and municipality within the Lugano District in the canton of Ticino, Switzerland. It is the largest city in both Ticino and the Italian-speaking region of southern Switzerland. Lugano has a population () of , and an u ...

, Garda,

Iseo Iseo may refer to: Acronyms * International Sustainable Energy Organization (ISEO) Places Italy * Iseo, Lombardy, a ''comune'' in the Province of Brescia * Lake Iseo, a lake in the Provinces of Bergamo and Brescia, Lombardy * Provaglio d'Ise ...

and other fluvial lakes on the left bank of the Po drainage system. Introductions of this species to

Arno The Arno is a river in the Tuscany region of Italy. It is the most important river of central Italy after the Tiber. Source and route The river originates on Monte Falterona in the Casentino area of the Apennines, and initially takes a sou ...

River system, which flows into the

Ligurian Sea The Ligurian Sea is an arm of the Mediterranean Sea. It lies between the Italian Riviera ( Liguria) and the island of Corsica. The sea is thought to have been named after the ancient Ligures people. Geography The sea borders Italy as far as ...

, as well as some lakes in the Appennino Tosco-Emiliano National Park and to

Lazio Lazio ( , ; ) or Latium ( , ; from Latium, the original Latin name, ) is one of the 20 Regions of Italy, administrative regions of Italy. Situated in the Central Italy, central peninsular section of the country, it has 5,714,882 inhabitants an ...

, but there is a lack of information on these. The Italian roach is found in oligotrophic, subalpine lakes and slow-moving reaches of large perennial river channels. It has colonised some lakes resulting from gravel extraction in the upper Po Valley.

Conservation

The pigo is classified as Vulnerable by the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

. It has a restricted range and its habitat is being degraded by many anthropogenic factors including pollution, damming, water abstraction and non-native

invasive species An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...

References

{{Taxonbar, from=Q925796 pigus Fish described in 1803 Taxa named by Bernard Germain de Lacépède Taxonomy articles created by Polbot Habitats Directive species