Order:	Cypriniformes
Family:	Cyprinidae
Genus and species:	Chondrostoma nasus

Alwyne Wheeler (1969) in "The Fishes of the British Isles and North West Europe":

Chondrostoma nasus (Linnaeus, 1758)

NAMES Fr. Hotu; Du. Sneep; Ge. Nase.

IDENTIFICATION This slim-bodied fish is only slightly compressed laterally. The snout projects and is broad and blunt. The mouth is inferior, and the upper lip thick. The lower lip is covered with a horny sheath, making a sharp cutting edge. The mouth is transverse or, in small fish, slightly arched. The dorsal fin origin is just in front of the base of the pelvic fins. It grows to 20 in (50 cm) and a weight of 3½ lb (1.79 kg).
The back is grey, shading to greeny-grey on the sides, and the belly yellowish. The dorsal and tail fins are grey or blackish, shaded with red, the other fins yellowish orange.
D. III/9-10; A. III/10-11; lateral line 57-62; transverse series 8-9/5-6; pharyngeal teeth mostly six each side, sometimes 7-6.

BIOLOGY It is found in deep, swiftly flowing water in the larger rivers, particularly in such places as upstream of weirs or near obstructions, such as wharf or bridge piles. It is a gregarious fish, usually keeping deep in the water in shoals of forty to a hundred. It spawns from February to April, after migrating upstream in large shoals, on gravelly shallows of the smaller river tributaries; the large eggs adhere to the gravel.
It eats mostly bottom-living organisms, both animal and plant. The principal item in its diet is the green alga growing on the stones and piles of the river.
It is fished for locally in rapids in the Rhine and Danube, where it forms a small fishery. It is seldom caught by anglers.
This fish has extended its range considerably within the last century, principally as a result of the construction of navigable waterways connecting river systems.
Closely related species are found in northern Italy, C. soetta Bonaparte, 1843 and in Spain C. polylepis Steindachner, 1866; both are similar in appearance to the `hotu' of northern France.

DISTRIBUTION

Eastwards to the Caspian Sea basin.