Chondrostoma

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Chondrostoma
Nose (Chondrostoma nasus)

Nose ( Chondrostoma nasus )

Systematics
without rank: Otophysa
Order : Carp-like (Cypriniformes)
Subordination : Carp fish-like (Cyprinoidei)
Family : White fish (Leuciscidae)
Subfamily : Leuciscinae
Genre : Chondrostoma
Scientific name
Chondrostoma
Agassiz , 1832

Chondrostoma is a genus of freshwater fish within the carp family . Their most noticeable feature is a well-developed, nose-like attachment that covers most of the upper lip. Together with fish of the genera Protochondrostoma , Pseudochondrostoma , Parachondrostoma , Achondrostoma and Iberochondrostoma , which have a similarly shaped upper lip, they are therefore also referred to in German as noses.

features

The fish of the genus Chondrostoma reach standard lengths of 135 to 470 mm. The bodies are cylindrical or laterally flattened. The adult fish have a deeply set mouth with a horny, often sharp-edged layer that covers the lower lip. The upper lip has a nose-like attachment. In some species the mouth is curved. In more specialized species, the front edge of the lower lip is straight. The morphology of the mouth changes during ontogenesis . For example, in Chondrostoma nasus, the mouth of adult fish is straight, while it is curved in juvenile fish.

Way of life

Most of the species in the genus Chondrostoma inhabit fast-flowing waters. Their diet consists of invertebrates and algae, which they scrape off stones or rocks on the stone floor.

Systematics

For a long time the name chondrostoma was used for a heterogeneous group of fish that shared a nose-like attachment on the upper lip. On the basis of genetic analyzes, the Spanish ichthyologist Benigno Elvira was able to determine in 1987 that these similarities are based solely on convergent evolution and that these fish differ through clearly defined molecular characteristics. Today, the following six genera are distinguished: Chondrostoma , Protochondrostoma , Pseudochondrostoma , Parachondrostoma , Achondrostoma and Iberochondrostoma . Molecular analyzes from 2008 suggested, however, that the genera Achondrostoma and Iberochondrostoma cannot be distinguished.

Species and their distribution

Geographically, the distribution areas of the genus Chondrostoma are divided into three regions.

The first region comprises the Volga region , the Black Sea , the Caspian Sea and the tributaries to the North Sea and the Baltic Sea . The following taxa occur here:

The second region includes the tributaries to the Mediterranean and the freshwater regions of the Balkan Peninsula , where the following species are represented:

The third region comprises the freshwater regions of the Caucasus , Turkey and the Middle East . Here are the ranges of the following species:

Individual evidence

  1. Benigno Elvira: A taxonomic revision of the genus Chondrostoma Agassiz, 1835 (Pisces, Cyprinidae) Cybium 11, 1987.
  2. Robalo, JI; Doadrio, I .; Valente, A. & Almada, VC (2008): Insights on speciation patterns in the genus Iberochondrostoma (Cyprinidae): Evidence from mitochondrial and nuclear data.

literature

  • Benigno Elvira: Taxonomy of the Genus Chondrostoma (Osteichtyes, Cyprinidae): An updated Review . In: Folia Zoologica - 46 (Suppl. 1): pp. 1-14 (1997). University of Madrid, Faculty of Biology
  • Maurice Kottelat: European Freshwater fishes. An heuristic checklist of the freshwater fishes of Europe (exclusive of former USSR), with an introduction for non-systematists and comments on nomenclature and conservation . Biologia (Bratislava) Sect. Zool., 52 (Suppl.). 1997.
  • Maurice Kottelat & Jörg Freyhof: Handbook of European Freshwater Fishes . 2007, ISBN 978-2-8399-0298-4 .

Web links

Commons : Chondrostoma  - collection of images, videos and audio files