''Romanogobio uranoscopus'', also known as the Danubian longbarbel gudgeon, Danubian gudgeon, Danube gudgeon or the steingressling, 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 ...

Gobionidae Gobioninae is a monophyletic family of Eurasian cyprinoid fishes. This is a species rich clade which, as a subfamily of the Cyprinidae was divided into five tribes: Gobionini, Pseudogobionini, Hemibarbini, Coreiini, and Sarcocheilichthyini. T ...

, the gudgeons. It can be found in Austria, Bulgaria, Croatia, Czech Republic, Germany, Hungary, Italy, Romania, Serbia and Montenegro, Slovakia, Slovenia and Ukraine.

Description

The Danube gudgeon grows to a maximum length of , though a more normal size is . It has a distinctive pair of

barbels In fish anatomy and turtle anatomy, a barbel is a slender, whisker like sensory organ near the mouth (sometimes called whiskers or tendrils). Fish that have barbels include the catfish, the carp, the goatfish, the hagfish, the sturgeon, the z ...

at the corner of the mouth which are long enough to extend back to beyond the eyes. These are tactile organs and are used to search through sediment for edible items. There are no scales on the throat and this helps distinguish it from its close relative, Kessler's gudgeon ''(Romanogobio kessleri)''. The dorsal fin has seven branched rays and the general colour is silver with a few dark spots. There is a thin blue streak that runs 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 ...

Distribution

The Danube gudgeon occurs in the rapid running tributaries of the River Danube but not in the main river except for its upper stretches. It favours sand and gravel bottoms.

Biology

Spawning takes place between May and September in shallow areas with stone or gravel bottoms. The fish rise to the surface in open water where the current is flowing at about . The eggs and milt are released and the fertilised eggs sink to the bottom and adhere there. The juveniles are diurnal but the adults are solitary and nocturnal. Both eat invertebrates of different kinds including

earthworm An earthworm is a soil-dwelling terrestrial invertebrate that belongs to the phylum Annelida. The term is the common name for the largest members of the class (or subclass, depending on the author) Oligochaeta. In classical systems, they we ...

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

larvae and

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

Status

The

IUCN Red List of Threatened Species The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological spe ...

lists the Danube gudgeon as being of "

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

". This is because the species is abundant and widespread throughout the fast flowing rivers of the Danube basin. However, it is sensitive to organic

pollution Pollution is the introduction of contaminants into the natural environment that cause harm. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the component ...

, and

sedimentation Sedimentation is the deposition of sediments. It takes place when particles in suspension settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to th ...

may have occurred because of the building of damns. It is likely to react adversely to human disturbance to its habitat. Although its populations appear to be declining slowly, this is gradual and does not warrant a higher level categorization.

References

{{Taxonbar, from=Q528704 uranscopus Freshwater fish of Europe Fish of Europe Taxa named by Louis Agassiz Fish described in 1828 Taxonomy articles created by Polbot Habitats Directive species