Iberian long-snout barbel  (Luciobarbus comizo)

The Iberian long-snout barbel is classified as Vulnerable (VU) on the IUCN Red List (1).

The Iberian long-snout barbel (Luciobarbus comizo) is a fairly large fish, most easily distinguished from other barbel species by its elongated head (2) (3) (4). There is a notable snout, and the head is somewhat concave in profile (4) (5). The body of the Iberian long-snout barbel is also elongated, especially in the tail region, where it narrows considerably (3) (4). Although this species can reach nearly a metre in length, it is usually closer to about 45 centimetres (3).

The dorsal fin of the Iberian long-snout barbel is set quite far back on the body, and the last simple (unbranched) ray of the fin is thick, bony and strongly serrated (2) (3) (4) (5). The tail fin is deeply notched, forming two distinct lobes (3). The female Iberian long-snout barbel generally grows larger than the male, and can also be distinguished by a distinctly larger anal fin. During the breeding season, males develop small projections, known as ‘nuptial tubercles’, on the front of the head (2) (3) (4).

Barbel species are usually characterised by possessing four barbels around the mouth (6), which in the Iberian long-snout barbel are relatively short in relation to the head (2) (3) (4). This species is quite variable in colour, but individuals are usually dark greenish on the upperparts and whitish on the underparts, sometimes with a pink or orange tinge. Smaller individuals, below about 15 centimetres in length, have black spots on the body (3).

Identifying Luciobarbus species can sometimes be difficult due to individuals that are intermediate in appearance, possibly as a result of hybridisation (7). For example, the Iberian long-snout barbel has been recorded hybridising with the related Iberian barbel (Luciobarbus bocagei) and Iberian small-head barbel (Luciobarbus microcephalus) (3) (8).

The Iberian long-snout barbel is endemic to the Tagus and Guadiana river basins of Spain and Portugal (1) (2) (3) (4) (5) (7). It was also formerly found in the Guadalquivir and Ebro basins, but now appears to have been lost from these locations (3) (4) (5) (7).

This species inhabits the lower and middle reaches of rivers, preferring deep water with slow currents and abundant submerged vegetation (1) (2) (3) (4) (5). The Iberian long-snout barbel has also been recorded in reservoirs (1) (3) (7) and estuaries (3).

The diet of the Iberian long-snout barbel includes invertebrates, detritus and plant material, including algae. It also sometimes eats other fish (2) (4) (5), and is adapted to capture prey in open water (3). Juvenile Iberian long-snout barbels generally take more invertebrates, while adults feed more on fish and plant material (3) (5). The diet of this species also varies seasonally (3). Like other members of the Cyprinidae family, the Iberian long-snout barbel lacks teeth in the jaws, instead possessing a specialised pair of enlarged bones in the throat, the ‘teeth’ of which are used to process food (6).

Relatively little is known about reproduction in the Iberian long-snout barbel, but it is believed to spawn between April and June (2) (3) (4) (5). At the start of the breeding season, the adult Iberian long-snout barbels migrate upstream to suitable spawning areas, usually in shallow, fast-flowing waters. This species is able to move through very shallow sections of water, sometimes even exposing the top of the body to the air, and can also leap past obstacles along its route. After spawning, the adults return to deeper, stiller waters, while the juveniles remain in shallow areas (3).

Juvenile Iberian long-snout barbels often join together in schools, but adults are more solitary, at least outside of the breeding season (3). The Iberian long-snout barbel has been recorded living to about 14 years old (3).

The Iberian long-snout barbel is undergoing a decline due to a combination of habitat loss, habitat degradation and introduced fish species. The rivers it inhabits are being degraded by water extraction, pollution, and the extraction of aggregates (crushed rock and gravel), which destroys this species’ spawning grounds (1) (2) (3) (4) (7). Dams, weirs and other structures are also presenting an increasing number of obstacles to the Iberian long-snout barbel’s migration (3).

A variety of non-native fish species have been introduced within the Iberian long-snout barbel’s range, including the pumpkinseed (Lepomis gibbosus), black bullhead (Ameiurus melas), largemouth bass (Micropterus salmoides) and pike (Esox lucius) (3) (4). These exotic species are thought to be threatening endemic fish, including the Iberian long-snout barbel, through a combination of predation, competition, and the spread of disease and parasites (3) (7).

The Iberian long-snout barbel is listed on Annex III of the Bern Convention (9) and on Annexes II and V of the European Union Habitats Directive (10). It is also listed as Endangered in the Portuguese Red Book (7) and as Vulnerable in the Spanish Red Book (4).

Conservation measures recommended for the Iberian long-snout barbel include protecting its habitat, for example by improving water quality and controlling water and aggregate extraction. The impacts of water infrastructure projects such as dams also need to be addressed, and measures need to be taken to control non-native species and to prevent further introductions (2) (4) (7). Finally, the Iberian long-snout barbel would also benefit from population monitoring and further research into its biology and ecology (7).

Find out more about the Iberian long-snout barbel and its conservation:

• FishBase - Iberian barbel:
  http://www.fishbase.org/Summary/SpeciesSummary.php?ID=9585&AT=Iberische+Barbe
• Atlas y Libro Rojo de los Peces Continentales de España - Barbus comizo:
  http://www.marm.es/imagenes/es/09047122800af640_tcm7-22078.pdf (In Spanish)
• Livro Vermelho dos Vertebrados de Portugal - Barbus comizo:
  http://portal.icnb.pt/NR/rdonlyres/CB478D55-FC7C-4EE2-AEFC-84B423307566/3096/LVVP_Peixes_Barbuscomizo.pdf (In Portuguese)
• Enciclopedia Virtual de los Vertebrados Españoles: Barbo comizo - Luciobarbus comizo:
  http://www.vertebradosibericos.org/peces/pdf/luccom.pdf (In Spanish)