The European river lamprey (''Lampetra fluviatilis''), also known as the river lamprey or lampern, is a species of freshwater

lamprey Lampreys (sometimes inaccurately called lamprey eels) are an ancient extant lineage of jawless fish of the order Petromyzontiformes , placed in the superclass Cyclostomata. The adult lamprey may be characterized by a toothed, funnel-like s ...

Description

Adult river lampreys measure from for the sea-going forms and up to for the lake forms. The very elongate body is a uniform dark grey above, lightening to yellowish off-white on the sides and pure white below. Like all lampreys, these fish lack paired fins and possess a circular sucking disc instead of

jaw The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth and serv ...

s. They have a single nostril and seven small breathing holes on either side behind the eye. The teeth are sharp and these fish can be told from the rather smaller

brook lamprey The brook lamprey (''Lampetra planeri'', also known as the European brook lamprey and the western brook lamprey) is a small European lamprey species that exclusively inhabits freshwater environments. The species is related to, but distinct from, ...

(''Lampetra planeri'') by the fact that the two dorsal fins are more widely separated.

Distribution

The European river lamprey is found in coastal waters around almost all of Europe from the north-west

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

north to the lakes of

Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...

, Scotland, Norway (

Mjøsa Mjøsa is Norway's largest lake, as well as one of the deepest lakes in Norway and in Europe. It is the fourth-deepest lake in Norway. It is located in the southern part of Norway, about north of the city of Oslo. Its main tributary is the rive ...

Wales Wales ( cy, Cymru ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by England to the Wales–England border, east, the Irish Sea to the north and west, the Celtic Sea to the south west and the ...

(

Cors Caron Cors Caron is a raised bog in Ceredigion, Wales. Cors is the Welsh word for "bog". Cors Caron covers an area of approximately .The Ramsar site is 874 ha. Cors Caron represents the most intact surviving example of a raised bog landscape in the Un ...

), and Russia, including rivers in the

Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Sw ...

; especially in Nakkila, Finland, European river lampreys are a traditional local delicacy. Initially, in 1996, its conservation status was rated "

near threatened A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify fo ...

" but since 2008 it has been rated as being of "

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

" following recovery of populations after pollution problems in central and western Europe. An assessment for the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from ...

published in 2014, however, classified the river lamprey as ''Near Threatened'' in this region. In August 2018, Spain declared it officially extinct in its territory.

Prey

Like many lampreys, this species feeds as an

ectoparasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

and

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

of fish. It clings on to the flanks or gills of the fish with its sucker and rasps at the tissues below.

Taxonomy

River lampreys belong to the same genus as

and are thought to be very closely related. Current thinking suggests that European brook and river lampreys are a paired species, which means the river lamprey represents the

anadromous Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousan ...

(seagoing) form of the resident brook lamprey. However, this is an area that is still being actively researched.

Reproductive cycle

The European river lamprey has a reproduction cycle similar to that of

salmon Salmon () is the common name for several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the family (biology), family Salmonidae, which are native to tributary, tributaries of the ...

. River lampreys migrate upstream from the sea to spawning grounds in autumn and winter. Spawning activity is greatest in the springtime (like the brook lamprey) and after spawning, the adults die. The young larvae, known as ammocoetes, spend several years in soft sediment before migrating to the sea as adults. It is thought that these fish spend two to three years in marine habitats before making the return trip to spawn.

Statistics

As ammocoetes, identification of these animals beyond genus level (''Lampetra'') is difficult because of their close similarity to brook lamprey. They average 30 cm in length as adults, and some may be considerably smaller (20 cm), but in each case they are distinctly larger than adult brook lamprey (12–14 cm). They are generally 150 g in mass, and their maximum life span is roughly 10 years. River lamprey mouth labelled.jpg, Mouth of a river lamprey Lampetra_fluviatilis.jpg, Top view

Description

Distribution

Prey

Taxonomy

Reproductive cycle

Statistics

See also

References

Further reading